Pathophysiology: The Biologic Basis for Disease in Adults and Children (9th) edition Questions and Answers

Chapter 01: Cellular Biolog

MULTIPLE CHOICE

 

1.         Which statement best describes the cellular function of metabolic absorption?

a.       Cells can produce proteins.

b.      Cells can secrete digestive enzymes.

c.       Cells can take in and use nutrients.

d.      Cells can synthesize fats.

 

 

ANS: C

In metabolic absorption, all cells take in and use nutrients and other substances from their surroundings. The remaining options are not inclusive in their descriptions of cellular metabolic absorption.

 

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2.         Where is most of a cell’s genetic information, including RNA and DNA, contained? a. Mitochondria

b.      Ribosome

c.       Nucleolus

d.      Lysosome

 

 

ANS: C

The nucleus contains the nucleolus, a small dense structure composed largely of RNA, most of the cellular DNA, and the DNA-binding proteins, such as the histones, which regulate its activity. The mitochondria are responsible for cellular respiration and energy production. Ribosomes’ chief function is to provide sites for cellular protein synthesis. Lysosomes function as the intracellular digestive system.

 

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3.         Which component of the cell produces hydrogen peroxide (H2O2) by using oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction? a. Lysosomes

b.      Peroxisomes

c.       Ribosomes

d.      Endosome

 

 

ANS: B

Peroxisomes are so named because they usually contain enzymes that use oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction that produces H2O2, which is a powerful oxidant and potentially destructive if it accumulates or escapes from peroxisomes. Ribosomes are RNA-protein complexes (nucleoproteins) that are synthesized in the nucleolus and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore complexes. Lysosomes are saclike structures that originate from the Golgi complex and contain more than 40 digestive enzymes called hydrolases, which catalyze bonds in proteins, lipids, nucleic acids, and carbohydrates. An endosome is a vesical that has been pinched off from the cellular membrane.

 

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4.         Which cell component is capable of cellular autodigestion when it is released during cell injury? a. Ribosome

b.      Golgi complex

c.       Smooth endoplasmic reticulum

d.      Lysosomes

 

 

ANS: D

The lysosomal membrane acts as a protective shield between the powerful digestive enzymes within the lysosome and the cytoplasm, preventing their leakage into the cytoplasmic matrix. Disruption of the membrane by various treatments or cellular injury leads to a release of the lysosomal enzymes, which can then react with their specific substrates, causing cellular selfdigestion. The chief function of a ribosome is to provide sites for cellular protein synthesis. The Golgi complex is a network of flattened, smooth vesicles and membranes often located near the cell nucleus. The smooth endoplasmic reticulum is involved in steroid hormone production and removing toxic substances from the cell.

 

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5.         Which cAMP-mediated response is related to antidiuretic hormone?

a.       Increased heart rate and force of contraction

b.      Secretion of cortisol

c.       Increased retention of water

d.      Breakdown of fat

 

 

ANS: C

Antidiuretic hormone leads to increased retention of water in the body. Epinephrine causes increases in heart rate and force of contraction. Increased cortisol secretion is due to ACTH. Breakdown of fat is due to glucagon.

 

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6.         During which phase of the cell cycle is DNA synthesized?

a.       G1

b.      S

c.       G2

d.      M

 

 

ANS: B

The four designated phases of the cell cycle are: (1) the G1 phase (G = gap), which is the period between the M phase (M = mitosis) and the start of DNA synthesis; (2) the S phase (S = synthesis), during which DNA is synthesized in the cell nucleus; (3) the G2 phase, during which RNA and protein synthesis occurs, the period between the completion of DNA synthesis and the next phase (M); and (4) the M phase, which includes nuclear and cytoplasmic division.

 

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7.         What organic compound facilitates transportation across cell membranes by acting as receptors, transport channels for electrolytes, and enzymes to drive active pumps? a. Lipids

b.      Proteases

c.       Proteins

d.      Carbohydrates

 

 

ANS: C

Proteins have several functions, including acting as receptors, transport channels for electrolytes, and enzymes to drive active pumps Lipids help act as the “glue” holding cell membranes together. Proteases cause the breakdown of protein. Carbohydrates are involved in cellular protection and lubrication and help produce energy via oxidative phosphorylation.

 

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8.         Understanding the various steps of proteolytic cascades may be useful in designing drug therapy for which human diseases?

a.       Cardiac and vascular disorders

b.      Autoimmune and malignant disorders

c.       Gastrointestinal and renal disorders

d.      Endocrine and gastrointestinal disorders

 

 

ANS: B

Understanding the various steps involved in this process is crucial for designing drug interventions. Dysregulation of proteases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders. Cardiac, vascular, gastrointestinal, renal, and endocrine disorders do not involve this process.

 

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9.         Which structure prevents water-soluble molecules from entering cells across the plasma membrane?

a.       Carbohydrate chains

b.      Glycoprotein channels

c.       Membrane channel proteins

d.      Lipid bilayer

 

 

ANS: D

The bilayer’s structure accounts for one of the essential functions of the plasma membrane. It is impermeable to most water-soluble molecules (molecules that dissolve in water) because the water-soluble molecules are insoluble in the oily core region. The bilayer serves as a barrier to the diffusion of water and hydrophilic substances while allowing lipid-soluble molecules, such as oxygen (O2) and carbon dioxide (CO2), to diffuse through it readily. Carbohydrate chains, glycoprotein channels, and membrane channel proteins do not prevent water-soluble molecules from entering cells across the cell membrane.

 

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10.     A student asks for an explanation of the absolute refractory period of the action potential. What response by the professor is best?

a.       A stronger than normal impulse will evoke another response.

b.      No stimulus is able to evoke another response at this time.

c.       Multiple stimuli can produce more rapid action potentials.

d.      The hyperpolarized state means a weaker stimulus produces a response.

 

 

ANS: B

During the absolute refractory state of the action potential, no stimulus is able to evoke another response from the cell. A stronger than normal impulse may generate a response in the relative refractory period. This period of time is not related to the number of stimuli. A hyperpolarized state means a stronger than normal stimulus would be needed to generate a response.

 

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11.     Which form of cell communication is used to communicate within the cell itself and with other cells in direct physical contact?

a.       Protein channel (gap junction)

b.      Plasma membrane-bound signaling molecules

c.       Hormone secretion such as neurotransmitters

d.      Extracellular chemical messengers such as ligands

 

 

ANS: B

Cells communicate in three main ways; they display plasma membrane-bound signaling molecules that affect the cell itself and other cells in direct physical contact with it, they affect receptor proteins inside the target cell, and they form protein channels (gap junctions) that directly coordinate the activities of adjacent cells. Neurotransmitters are released by neurons and cross the synaptic cleft to communicate with the cells they innervate. Ligands are involved in binding processes.

 

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12.     Which mode of chemical signaling uses blood to transport communication to cells some distance away?

a.       Paracrine

b.      Autocrine

c.       Neurotransmitter

d.      Hormonal

 

 

ANS: D

Chemical signaling can be classified into three categories: (1) local-chemical mediator, (2) hormone, and (3) neurotransmitter. Hormones are released by one set of cells and travel through tissues or the bloodstream to another set of cells where they produce a response by those cells. In paracrine signaling, cells secrete local chemical mediators that are quickly absorbed, destroyed, or immobilized. Paracrine signaling requires close membrane-to-membrane contact. Paracrine signaling usually involves different cell types; however, cells also may produce signals that they, themselves, respond to, which is called autocrine signaling. Neurotransmitters are released by neurons and cross the synaptic cleft to communicate with the cells they innervate.

 

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13.     Which mode of chemical signaling uses local chemical mediators that are quickly taken up, destroyed, or immobilized? a. Paracrine

b.      Autocrine

c.       Neurotransmitter

d.      Hormone

 

 

ANS: A

In paracrine signaling, cells secrete local chemical mediators that are quickly taken up, destroyed, or immobilized. Autocrine signaling occurs when the target cells produce signals that they themselves respond to. Neurotransmitters are released by neurons and cross the synaptic cleft to communicate with the cells they innervate. Hormones are released by one set of cells and travel through tissues or the bloodstream to another set of cells where they produce a response by those cells.

 

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14.     Neurotransmitters affect the postsynaptic membrane by binding to which structure? a. Lipids

b.      Ribosomes

c.       Amphipathic lipids

d.      Receptors

 

 

ANS: D

In each type of chemical signaling, the target cell receives the signal by first attaching to its receptors. The other options do not correctly describe this process.

 

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15.     How do cells receive communication from the extracellular fluid surrounding them?

a.       Protein channel (gap junction)

b.      Plasma membrane-bound signaling molecules (involving receptors)

c.       Hormone secretion such as neurotransmitters

d.      Chemical messengers such as ligands

 

 

ANS: D

Signal transduction involves incoming signals or instructions from extracellular chemical messengers (ligands) that are conveyed to the cell’s interior for execution. The other options do not correctly describe how cells receive communication from the surrounding extracellular fluid.

 

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16.     Which molecule provides the second messenger necessary for extracellular communication to be activated?

a.       Guanosine triphosphate (GTP)

b.      Adenosine monophosphate (AMP)

c.       Adenosine triphosphate (ATP)

d.      Guanosine diphosphate (GDP)

 

 

ANS: B

The two major second-messenger pathways are cyclic AMP (cAMP) and calcium (Ca++). GTP, ATP, and GDP are not major second-messenger pathways. GTP and GDP are “middlemen” or intermediaries. Nutrients are transformed into energy in the form of ATP.

 

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17.     Under anaerobic conditions, what process provides energy for the cell?

a.       Oxidative phosphorylation

b.      Glycolysis

c.       Lactolysis

d.      Passive transport

 

 

ANS: B

Glycolysis provides energy to the cells when oxygen delivery is insufficient or delayed. Oxidative phosphorylation is the process by which energy produced from nutrients is transferred to ATP. Lactolysis is the breakdown of lactose. Passive transport is the movement of water and small, nonelectrically charge molecules across plasma membranes.

 

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18.     What is the mechanism by which the energy produced from carbohydrates, proteins, and lipids is transferred to adenosine triphosphate (ATP)? a. Anaerobic glycolysis

b.      Oxidative cellular metabolism

c.       Oxidative phosphorylation

d.      Tricarboxylic acid phosphorylation

 

 

ANS: C

Oxidative phosphorylation occurs in the mitochondria and is the mechanism by which the energy produced from carbohydrates, fats, and proteins is transferred to ATP. Glycolysis provides energy to the cells when oxygen delivery is insufficient or delayed. Oxidative cellular metabolism and tricarboxylic acid phosphorylation are not involved in transferring energy to ATP.

 

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19.     Passive transport is best described with which statement?

a.       Being driven by osmosis, hydrostatic pressure, and diffusion

b.      Involving receptors that can bind with substances being transported

c.       Being capable of transporting macromolecules

d.      Requiring energy generated by the cell

 

 

ANS: A

Water and small electrically uncharged molecules move easily through pores in the plasma membrane’s lipid bilayer. This process, called passive transport, naturally occurs through any semipermeable barrier. It is driven by osmosis, hydrostatic pressure, and diffusion, all of which depend on the laws of physics and do not require life. The other options do not correctly describe passive transport.

 

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20.     Which is the best example of active transport?

a.       Movement across a membrane due to differences in solute concentration

b.      Movement requiring the expenditure of metabolic energy

c.       Movement of two molecules simultaneously in one direction

d.      Movement of two molecules simultaneously in opposite directions

 

 

ANS: B

Active transport requires a life, biologic activity, and the expenditure of metabolic energy. Movement due simply to differences in concentration gradients is called passive transport. Movement of two molecules in the same direction is called symport, while moving two molecules in opposite directions is called antiport.

 

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21.     Which method of transport uses transmembrane proteins with receptors with a high degree of specificity for the substance being transported? a. Active

b.      Mediated

c.       Transmembranous

d.      Passive

 

 

ANS: B

Mediated transport (passive and active) involves integral or transmembrane proteins with receptors having a high degree of specificity for the substance being transported. Active and passive transport are opposites with active transport requiring the use of energy and passive transport relying on osmosis, hydrostatic pressure, and diffusion and not energy.

Transmembranous means “across membranes.”

 

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22.     The movement of fluid across the arterial end of capillary membranes into the interstitial fluid surrounding the capillary is an example of which fluid movement process? a. Hydrostatic pressure

b.      Osmosis

c.       Diffusion

d.      Active transport

 

 

ANS: A

Hydrostatic pressure is the mechanical force of water pushing against cellular membranes. Osmosis is the movement of water “down” a concentration gradient, that is, across a semipermeable membrane from a region of higher water concentration to a region of lower water concentration. Diffusion is the movement of a solute molecule from an area of greater solute concentration to an area of lesser solute concentration. Active transport requires a life, biologic activity, and the expenditure of metabolic energy.

 

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23.     A student asks why osmolality is preferred over osmolarity as the measurement of osmotic activity in the clinical assessment of individuals. What response by the professor is most accurate?

a.       Plasma contains sodium and chloride, which influence the volume of solution.

b.      Volume affects perfusion more than the weight of solutes.

c.       More of the weight of plasma is influenced by solutes rather than by water.

d.      Osmotic activity depends on the concentration of solutes present in plasma.

 

 

ANS: C

Osmolality is a measure of the number of milliosmoles per kilogram (mOsm/kg) of water, or the concentration of molecules per weight of water. Osmolarity is a measure of the number of milliosmoles per liter (mOsm/L) of solution, or the concentration of molecules per volume of solution. Osmolality is a measure of the number of milliosmoles per kilogram (mOsm/kg) of water, or the concentration of molecules per weight of water. Osmolarity is a measure of the number of milliosmoles per liter (mOsm/L) of solution, or the concentration of molecules per volume of solution. In plasma, less of the plasma weight is water; therefore the overall concentration of particles is greater. The osmolality will be greater than the osmolarity because of the smaller proportion of water. Osmolality is thus the preferred measure of osmotic activity in clinical assessment of individuals.

 

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24.     A patient who has diarrhea receives a 3% saline solution intravenously to replace the sodium and chloride lost in the stool. What effect will this fluid replacement have on cells? a. Become hydrated

b.      Swell or burst

c.       Shrink

d.      Divide

 

 

ANS: C

A hypertonic solution has a concentration of greater than 285 to 294 mOsm/kg. An example of a hypertonic solution is 3% saline solution. Water can be pulled out of the cells by a hypertonic solution; therefore the cells shrink. An isotonic solution will cause the cells to become more hydrated without disrupting the osmolality of either intracellular or extracellular fluid. Hypotonic solutions can cause cells to swell or burst. No solutions lead to cell division.

 

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25.     The transport of glucose from the blood to the cell is accomplished by which process? a. Hydrostatic pressure

b.      Active diffusion

c.       Passive osmosis

d.      Mediated transport

 

 

ANS: D

Mediated transport is the means by which glucose is transported from the blood to the cells. This process uses transport proteins. Hydrostatic pressure is the force of water pushing against a cell membrane. Diffusion is a passive process, not active. Osmosis is the movement of water “down” a concentration gradient, that is, across a semipermeable membrane from a region of higher water concentration to a region of lower water concentration and is a passive process.

 

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26.     What transports potassium and sodium across plasma membranes?

a.       Passive electrolyte channels

b.      Coupled channels

c.       Adenosine triphosphatase (ATPase) enzyme

d.      Diffusion

 

 

ANS: C

The exact mechanism for the transport of Na+ and K+ across the membrane is uncertain. One proposal is that ATPase enzyme induces the transporter protein to undergo several conformational changes, causing Na+ and K+ to move short distances (see Figure 1-29). The remaining options do not correctly describe the means by which K+ and Na+ are transported.

 

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27.     What occurs during exocytosis?

a.       Macromolecules can be secreted across eukaryotic cell membranes.

b.      All substances are secreted into the cellular matrix.

c.       No repairs in the plasma membrane can take place.

d.      Solute molecules flow freely into and out of the cell.

 

 

ANS: A

In eukaryotic cells, secretion of macromolecules almost always occurs by exocytosis. The remaining options do not correctly describe exocytosis.

 

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28.     The cellular uptake of the nutrient cholesterol depends on which process?

a.       Receptor-mediated exocytosis

b.      Antiport system

c.       Receptor-mediated endocytosis

d.      Passive transport

 

 

ANS: C

The cellular uptake of nutrients, such as cholesterol, for example, depends on receptor-mediated endocytosis. Nutrients are not transported via the other options.

 

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29.     What causes the rapid change in the resting membrane potential to initiate an action potential?

a.       Potassium gates open, and potassium rushes into the cell, changing the membrane potential from negative to positive.

b.      Sodium gates open, and sodium rushes into the cell, changing the membrane potential from negative to positive.

c.       Sodium gates close, allowing potassium into the cell to change the membrane potential from positive to negative.

d.      Potassium gates close, allowing sodium into the cell to change the membrane potential from positive to negative.

 

 

ANS: B

When a resting cell is stimulated through voltage-regulated channels, the cell membranes become more permeable to Na+. As Na+ moves into the cell the membrane potential decreases, or moves forward, from a negative value (in millivolts) to zero. The Na+ gates open, and Na+ rushes into the cell, causing the membrane potential to reduce to zero and then become positive (depolarization). The remaining options do not correctly describe the change that initiates an action potential.

 

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30.     The action of platelet-derived growth factor is to stimulate the production of which cells? a. Platelets

b.      Epidermal cells

c.       Connective tissue cells

d.      Fibroblast cells

 

 

ANS: C

Different types of cells require different factors to stimulate proliferation; for example, plateletderived growth factor stimulates the production of connective tissue cells. Platelet-derived growth factor does not stimulate production of platelets, epidermal cells, or fibroblasts.

 

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31.     What role do cytokines play in cell reproduction?

a.       Provide growth factor for tissue growth and development

b.      Block progress of cell reproduction through the cell cycle

c.       Restrain cell growth and development

d.      Provide nutrients for cell growth and development

 

 

ANS: A

Growth factors, also called cytokines, stimulate an increase in cell mass or cell growth by promoting the synthesis of proteins and other macromolecules and inhibiting their degradation.

 

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32.     What is the process of cellular reproduction?

a.       The process often takes months or years to complete.

b.      Cellular reproduction typically has a short interphase.

c.       Two diploid cells, called daughter cells, have been formed.

d.      The process involves the interaction of male and female cells.

 

 

ANS: C

During telophase, the final stage of cellular reproduction, two identical diploid cells, called daughter cells, has been formed from the original cell. The process occurs hundreds of times a second. Interphase is the longest phase of the cell cycle. Male and female cells do not interact in cellular reproduction; each cell is responsible for reproducing itself.

 

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33.     Which statement is true about eukaryotic cells?

a.       They lack distinct nucleus.

b.      They contain compartments called organelles.

c.       They lack an encasing nuclear membrane.

d.      They are smaller than the typical prokaryote cell.

 

 

ANS: B

Eukaryotic cells have a characteristic set of membrane-bound intracellular compartments called organelles that include a well-defined nucleus encased in a nuclear membrane. Eukaryotic cells are also larger than prokaryotes.

 

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34.     Which statement is true about phagocytosis?

a.       Phagocytosis is an example of exocytosis.

b.      Phagocytosis is dependent on small vesicles.

c.       Phagocytosis involves the ingestion of bacteria.

d.      Phagocytosis focuses on solute molecules.

 

 

ANS: C

Phagocytosis is the engulfment of large particles in phagocytic cells. Phagocytosis is an example of endocytosis, not exocytosis and does not focus on solutes.

 

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35.     A muscle cell possesses which specialized function?

a.       Movement

b.      Conductivity

c.       Secretion

d.      Respiration

 

 

ANS: A

A cell has the potential to differentiation and to gain the ability to perform one of eight specialized functions. Muscle cells can generate forces that produce motion. Nerves cells are capable of conductivity. Cells of the adrenal gland, testis, and ovary can secrete. Respiration is a function that all cells possess.

 

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36.     When a mucous gland cell creates a new substance from previously absorbed material, this process is known as which specialized cellular function? a. Excretion

b.      Metabolic absorption

c.       Reproduction

d.      Secretion

 

 

ANS: D

Certain cells, such as mucous gland cells, can synthesize new substances from substances they absorb and then secrete the new substances to serve elsewhere as needed. Excretion occurs when cells rid themselves of waste products. Reproduction is the process of forming new cells.

 

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37.     All cells are capable of what process?

a.       Excretion

b.      Movement

c.       Conductivity

d.      Continuous division

 

 

ANS: A

All cells have the capacity to excrete, thus allowing them to rid themselves of waste products resulting from the metabolic breakdown of nutrients. Muscle cells have the property of movement. Conductivity is a property of nerve cells. Many, but not all, cells are capable of reproduction.

 

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38.     What is the best description of cell cycle arrest?

a.       The cell cycle is stopped due to damaged DNA.

b.      Programmed cell death is suppressed.

c.       Macromolecule degradation is inhibited.

d.      Production of growth factors is halted.

 

 

ANS: A

The DNA damage response occurs when DNA is damaged and several protein kinases are recruited to the site of damage and start a signaling pathway that stops the progression of the cell cycle, or cell cycle arrest. Cell cycle arrest does not involve suppressing programmed cell death, macromolecule degradation, or growth factor production.

 

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MULTIPLE RESPONSE

 

1.      What are the major chemical components of the cell membranes? (Select all that apply.) a. Lipids

b.      Sodium ions

c.       Carbohydrates

d.      DNA

e.       Proteins

 

 

ANS: A, E

The major chemical components of all cell membranes are lipids and proteins. Sodium ions, carbohydrates, and DNA are not major chemical components of cell membranes.

 

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2.      Which statements are true concerning the process of mediated transport? (Select all that apply.) a. Can be active or passive

b.      Only moves one molecule at a time

c.       Involves transport proteins

d.      Expends tremendous energy

e.       Occurs only with hormones

 

 

ANS: A, C

Mediated transport uses membrane transport proteins and can be either active or passive. Mediated transport systems can move molecules singly or two at a time and may or may not use energy. Many substances can be moved through mediated transport.

 

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3.      What is passive transport dependent on? (Select all that apply.)

a.       Semipermeable barrier membrane

b.      The process of osmosis

c.       Diffusion as a driving force

d.      A living host

e.       Hydrostatic pressure

 

 

ANS: A, B, C, E

Passive transport naturally occurs through any semipermeable barrier. It is driven by osmosis, hydrostatic pressure, and diffusion, all of which depend on the laws of physics and do not require life.  

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4.      What is the primary function of proteins? (Select all that apply.)

a.       Proteins are binding units.

b.      Proteins are transport channels.

c.       Proteins are ribonucleoproteins.

d.      Proteins provide cell surface markers.

e.       Proteins are chemical reaction catalysts.

 

 

ANS: A, B, D, E

Protein functions include (a) recognition and binding units (receptors) for substances moving in and out of the cell; (b) pores or transport channels; (c) enzymes that drive active pumps; (d) cell surface markers, such as glycoproteins; (e) cell adhesion molecules; and (f) catalysts of chemical reactions.

 

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Chapter 02: Altered Cellular and Tissue Biology: Environmental Agents

 

MULTIPLE CHOICE

 

1.         Which type of cell adaptation occurs when normal columnar ciliated epithelial cells of the bronchial lining have been replaced by stratified squamous epithelial cells? a. Hyperplasia

b.      Metaplasia

c.       Dysplasia

d.      Anaplasia

 

 

ANS: B

Metaplasia is the reversible replacement of one mature cell by another, sometimes a lessdifferentiated cell type. The best example of metaplasia is the replacement of normal columnarciliated epithelial cells of the bronchial (airway) lining by stratified squamous epithelial cells. The other options do not accurately describe the event in the question.

 

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2.         What does the loss of the adenosine triphosphate (ATP) during ischemia cause cells to do?

a.       Shrink because of the influx of calcium (Ca)

b.      Shrink because of the influx of potassium chloride (KCl)

c.       Swell because of the influx of sodium chloride (NaCl)

d.      Swell because of the influx of nitric oxide (NO)

 

 

ANS: C

A reduction in ATP levels causes the plasma membrane’s sodium–potassium (Na+–K+) pump and sodium–calcium exchange to fail, which leads to an intracellular accumulation of sodium and calcium and diffusion of potassium out of the cell. (The Na+–K+ pump is discussed in Chapter 1.) Sodium and water can then freely enter the cell, and cellular swelling results. The other options do not accurately describe the result of ATP at the cellular level.

 

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3.         The mammary glands enlarge during pregnancy primarily as a consequence of what hormonal process?

a.       Atrophy

b.      Hyperplasia

c.       Anaplasia

d.      Dysplasia

 

 

ANS: B

Hormonal hyperplasia occurs chiefly in estrogen-dependent organs, such as the uterus and breast. Atrophy is a decrease or shrinkage in cellular size. Anaplasia is a condition of poor cellular differentiation, a characteristic of cancer cells. Dysplasia is a change in the size, shape, and organization of mature cells.

 

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4.         Free radicals play a major role in the initiation and progression of which diseases?

a.       Cardiovascular diseases such as hypertension and ischemic heart disease

b.      Renal diseases such as acute tubular necrosis and glomerulonephritis

c.       Gastrointestinal diseases such as peptic ulcer disease and Crohn disease

d.      Muscular disease such as muscular dystrophy and fibromyalgia

 

 

ANS: A

Emerging data indicate that reactive oxygen species play major roles in the initiation and progression of cardiovascular alterations associated with hyperlipidemia, diabetes mellitus, hypertension, ischemic heart disease, and chronic heart failure. Free radical damage is not a contributing mechanism for the renal, gastrointestinal, or muscular diseases listed.

 

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5.         How do free radicals cause cell damage?

a.       Stealing the cell’s oxygen to stabilize the electron, thus causing hypoxia

b.      Stimulating the release of lysosomal enzymes that digest the cell membranes

c.       Transferring one of its charged, stabilized atoms to the cell membrane, which causes lysis

d.      Giving up an electron, which causes injury to the chemical bonds of the cell membrane

 

 

ANS: D

A free radical is an electrically uncharged atom or group of atoms having an unpaired electron. Having one unpaired electron makes the molecule unstable; thus to stabilize, the molecule gives up an electron to another molecule or steals one. Therefore it is capable of forming injurious chemical bonds with proteins, lipids, or carbohydrates—key molecules in membranes and nucleic acids. Free radical damage is not caused by hypoxia, lysosomal enzymes, or transferring atoms.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

6.         What is a consequence of plasma membrane damage to the mitochondria?

a.       Enzymatic digestion halts DNA synthesis.

b.      Influx of calcium ions halts ATP production.

c.       Edema from an influx in sodium causes a reduction in ATP production.

d.      Potassium shifts out of the mitochondria, which destroys the infrastructure.

 

 

ANS: B

Calcium alterations are an important mechanism of cell injury and death. Cell membrane injury leads to calcium influx into the cell. An influx of calcium ions from the extracellular compartment activates multiple enzyme systems, resulting in cytoskeleton disruption, membrane damage, activation of inflammation, and eventually DNA degradation. Calcium ion accumulation in the mitochondria causes the mitochondria to swell, which is an occurrence that is associated with irreversible cellular injury. The injured mitochondria can no longer generate ATP, but they do continue to accumulate calcium ions. Mitochondrial consequences of cell membrane damage do not include enzymatic digestion, reduced ATP production due to edema, or infrastructure damage from potassium shifts.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

7.         What is a consequence of leakage of lysosomal enzymes during chemical injury?

a.       Enzymatic digestion of the nucleus and nucleolus occurs, halting DNA synthesis.

b.      Influx of potassium ions into the mitochondria occurs, halting the ATP production.

c.       Edema of the Golgi body prevents the transport of proteins out of the cell.

d.      Shift of calcium out of the plasma membrane occurs, destroying the cytoskeleton.

 

 

ANS: A

Acid hydrolases from leaking lysosomes are activated in the reduced pH of the injured cell and they digest cytoplasmic and nuclear components. Influx of potassium ions into the mitochondria, edema of Golgi bodies, and calcium destruction of the cytoskeleton are not a consequence of leakage of lysosomal enzymes during chemical injury.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

8.         Lead causes damage within the cell by interfering with the action of what?

a.       Sodium and chloride

b.      Potassium

c.       Calcium

d.      ATP

 

 

ANS: C

Lead affects many different biologic activities at the cellular and molecular levels, many of which may be related to its ability to interfere with the functions and homeostasis of calcium. Lead does not appear to cause damage by interfering with the action of sodium, chloride, potassium, or ATP.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

9.         A health professions student asks the professor to explain apoptosis. What response is most accurate?

a.       Programmed cell death

b.      Due to chemical injury

c.       Unpredictable patterns of cell death

d.      Results in benign malignancies

 

 

ANS: A

Apoptosis is an active process of cellular self-destruction, also known as programmed cell death, which is implicated in normal and pathologic tissue changes. Apoptosis causes cell death in many pathologic states, not just from chemical injury. A predictable, tightly regulated cellular program leads to apoptosis. Apoptosis does not cause benign malignancies.

 

                PTS: 1                     DIF: Cognitive Level: Understanding

 

10.     A healthcare professional is assessing a child whose parents report poor grades in school, trouble paying attention, and “naughty” behaviors that have become so frequent the child is always in trouble. For which health condition should the professional facilitate testing? a. Hypoxic injury

b.      Lead poisoning

c.       Mercury exposure

d.      Cadmium injection

 

 

ANS: B

Decreased academic achievement, IQ, and specific cognitive measures; increased incidence of attention-related behaviors and problem behaviors are related to lead exposure. Hypoxic injury is usually caused by ischemia, which is not apparent in this child. Exposure to mercury poisoning in utero can lead to deafness, blindness, intellectual disability, cerebral palsy, and central nervous system (CNS) defects. The main effects of cadmium poisoning are renal tubular disease and obstructive lung disease.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

11.     A student asks why carbon monoxide causes tissue damage. What response by the professor is best?

a.       Competes with carbon dioxide so that it cannot be excreted

b.      Binds to hemoglobin so that it cannot carry oxygen

c.       Destroys the chemical bonds of hemoglobin so it cannot carry oxygen

d.      Removes iron from hemoglobin so it cannot carry oxygen

 

 

ANS: B

Because carbon monoxide’s affinity for hemoglobin is 200 times greater than that of oxygen, it quickly binds with the hemoglobin, preventing oxygen molecules from doing so. Carbon monoxide does not cause tissue damage by competing with carbon dioxide, destroying chemical bonds, or removing iron from hemoglobin.

 

                PTS: 1                     DIF: Cognitive Level: Understanding

 

12.     A healthcare professional is working with a person who drinks several 6-packs of beer a week. What testing does the professional encourage the person to get? a. Hepatic function

b.      Gastrointestinal function

c.       Renal function

d.      Central nervous system function

 

 

ANS: A

Chronic alcohol use/abuse affects the hepatic system primarily. The gastrointestinal and renal systems are not as significantly impacted. Central nervous system problems are often seen in acute alcohol intoxication, and may be seen in advanced alcoholic liver disease.

 

                PTS: 1                     DIF: Cognitive Level: Comprehension

 

13.     During cell injury caused by hypoxia, why does an increase in the osmotic pressure within the cell occur?

a.       Plasma proteins enter the cell.

b.      The adenosine triphosphatase (ATPase)-driven pump is stronger during hypoxia.

c.       Sodium chloride enters the cell.

d.      An influx of glucose occurs through the injured cell membranes.

 

 

ANS: C

In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure of metabolism and a loss of ATP production. Normally, the pump that transports sodium ions out of the cell is maintained by the presence of ATP and ATPase, the active transport enzyme. In metabolic failure caused by hypoxia, reduced ATP and ATPase levels permit sodium to accumulate in the cell, whereas potassium diffuses outward. The increase of intracellular sodium increases osmotic pressure, which draws more water into the cell. (Transport mechanisms are described in Chapter 1.) The remaining options do not accurately describe the cell injury that results in increased osmotic pressure caused by hypoxia.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

14.     Which statement is true regarding the difference between subdural hematoma and epidural hematoma?

a.       No difference exists, and these terms may be correctly used interchangeably.

b.      A subdural hematoma occurs above the dura, an epidural hematoma occurs under the dura.

c.       A subdural hematoma is often the result of shaken baby syndrome, whereas an epidural hematoma rapidly forms as a result of a skull fracture.

d.      A subdural hematoma usually forms from bleeding within the skull, an epidural hematoma occurs from trauma outside the skull.

 

 

ANS: C

A subdural hematoma is a collection of blood between the inner surface of the dura mater and the surface of the brain, resulting from the shearing of small veins that bridge the subdural space. Subdural hematomas can be the result of blows, falls, or sudden acceleration-deceleration of the head, which occurs in the shaken baby syndrome. An epidural hematoma is a collection of blood between the inner surface of the skull and the dura and is almost always associated with a skull fracture. The other options do not accurately describe the differences between the two hematomas.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

15.     A healthcare professional is working at the health tent during a marathon. A runner is brought to the tent complaining of nausea and weakness. What is the first thing the professional should do?

a.       Call 911.

b.      Have the person lie down.

c.       Give the person salt tablets.

d.      Ask about street drug use.

 

 

ANS: B

Heat exhaustion is probably the most common heat-related injury. Symptoms include nausea and weakness due to hypovolemia. The person can suddenly collapse due to the loss of fluids, so the first measure the professional should take is to have the runner lie down. This is not a medical emergency so 911 does not yet need to be called. Salt replacement is the treatment for heat cramps. Street drug use could cause nausea or weakness, but since the person is running outside and sweating, a heat-related injury is far more likely.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

16.     In hypoxic injury, why does sodium enter the cell and cause swelling?

a.       The cell membrane permeability increases for sodium during periods of hypoxia.

b.      ATP is insufficient to maintain the pump that keeps sodium out of the cell.

c.       The lactic acid produced by the hypoxia binds with sodium in the cell.

d.      Sodium cannot be transported to the cell membrane during hypoxia.

 

 

ANS: B

In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure of metabolism and a loss of ATP production. Normally, the presence of ATP and ATPase, the active transport enzyme, maintains the pump that transports sodium ions out of the cell. In metabolic failure caused by hypoxia, reduced ATP and ATPase levels permit sodium to accumulate in the cell, whereas potassium diffuses outward. The other options do not accurately describe the cause of the swelling caused by hypoxia.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

17.     What is the most common site of lipid accumulation?

a.       Coronary arteries

b.      Kidneys

c.       Liver

d.      Subcutaneous tissue

 

 

ANS: C

Although lipids sometimes accumulate in heart and kidney cells, the most common site of intracellular lipid accumulation, or fatty change, is liver cells. Subcutaneous tissue is not a common site of lipid accumulation.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

18.     What mechanisms occur in the liver cells as a result of lipid accumulation?

a.       Accumulation of lipids that obstruct the common bile duct, preventing flow of bile from the liver to the gallbladder

b.      Increased synthesis of triglycerides from fatty acids and decreased synthesis of apoproteins

c.       Increased binding of lipids with apoproteins to form lipoproteins

d.      Increased conversion of fatty acids to phospholipids

 

 

ANS: B

Lipid accumulation in liver cells occurs after cellular injury sets the following mechanisms in motion: increased synthesis of triglycerides from fatty acids (increases in the enzyme, glycerophosphatase, which can accelerate triglyceride synthesis) and decreased synthesis of apoproteins (lipid-acceptor proteins). Accumulation of lipids does not cause obstruction of bile flow, increased binding of lipids with apoproteins, or conversion of fatty acids to phospholipids.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

19.     Hemoprotein accumulations are a result of the excessive storage of what?

a.       Iron, which is transferred from the cells to the bloodstream

b.      Hemoglobin, which is transferred from the bloodstream to the cells

c.       Albumin, which is transferred from the cells to the bloodstream

d.      Amino acids, which are transferred from the cells to the bloodstream

 

 

ANS: A

Excessive storage of iron, which is transferred to the cells from the bloodstream, causes hemoprotein accumulations in cells. Hemoglobin, albumin, or amino acids will not cause hemoprotein accumulations.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

20.     A patient suffered multiple traumatic injuries and received many blood transfusions within a few days of the injuries. For which medical condition should the healthcare professional monitor the patient for?

a.       High blood pressure

b.      HIV infection

c.       Hemosiderosis

d.      Kidney damage

 

 

ANS: C

Hemosiderosis is a condition that occurs only when excess iron is stored as hemosiderin in the cells of many organs and tissues. This condition is common in individuals who have received repeated blood transfusions or prolonged parenteral administration of iron. While blood transfusions can expose a person to infectious diseases, this is not as likely to be a problem since blood products are tested. Kidney damage may occur in patients with traumatic injuries, but is not directly related to the multiple blood transfusions.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

21.     What is the cause of free calcium in the cytosol that damages cell membranes by uncontrolled enzyme activation?

a.       Activation of endonuclease interferes with the binding of calcium to protein.

b.      Activation of phospholipases, to which calcium normally binds, degrades the proteins.

c.       An influx of phosphate ions competes with calcium for binding to proteins.

d.      Depletion of ATP normally pumps calcium from the cell.

 

 

ANS: D

If abnormal direct damage occurs to membranes or ATP is depleted, then calcium increases in the cytosol. The other options do not accurately describe the cause of free calcium in cytosol to damage cell membranes.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

22.     What two types of hearing loss are associated with noise?

a.       Acoustic trauma and noise-induced

b.      High frequency and low frequency

c.       High frequency and acoustic trauma

d.      Noise-induced and low frequency

 

 

ANS: A

Two types of hearing loss are associated with noise: (1) acoustic trauma or instantaneous damage caused by a single sharply rising wave of sound (e.g., gunfire), and (2) noise-induced hearing loss, the more common type, which is the result of prolonged exposure to intense sound (e.g., noise associated with the workplace and leisure-time activities). The remaining options are not related to noise but rather to the amplitude of the sound.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

23.     What type of necrosis results from ischemia of neurons and glial cells?

a.       Coagulative

b.      Liquefactive

c.       Caseous

d.      Gangrene

 

 

ANS: B

Liquefactive necrosis commonly results from ischemic injury to neurons and glial cells in the brain. Coagulative necrosis commonly occurs in the kidney, heart, and adrenal glands. Caseous necrosis is a combination of coagulative and liquefactive processes and is seen in tuberculosis. Gangrene refers to death of tissue and results from severe hypoxic injury, commonly occurring because of arteriosclerosis, or blockage, of major arteries, especially in the lower leg.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

24.     What type of necrosis is often associated with pulmonary tuberculosis? a. Bacteriologic

b.      Caseous

c.       Liquefactive

d.      Gangrenous

 

 

ANS: B

Caseous necrosis, which commonly results from tuberculous pulmonary infection, particularly Mycobacterium tuberculosis, is a combination of coagulative and liquefactive necrosis. The other types of necrosis are not observed in pulmonary tuberculosis.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

25.     What type of necrosis is associated with wet gangrene?

a.       Coagulative

b.      Liquefactive

c.       Caseous

d.      Gangrene

 

 

ANS: B

Wet gangrene develops only when neutrophils invade the site, causing liquefactive necrosis.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

26.     After ovulation, the uterine endometrial cells divide under the influence of estrogen. This process is an example of what hormonal process? a. Hyperplasia

b.      Dysplasia

c.       Hypertrophy

d.      Anaplasia

 

 

ANS: A

Hormonal hyperplasia chiefly occurs in estrogen-dependent organs, such as the uterus and breast. After ovulation, for example, estrogen stimulates the endometrium to grow and thicken for reception of the fertilized ovum. Dysplasia refers to abnormal changes in the size, shape, and organization of mature cells. Hypertrophy is an increase in the size of cells that consequently increases the size of the affected organ. Anaplasia is a condition of poor cellular differentiation, a characteristic of cancer cells. Dysplasia is a change in the size, shape, and organization of mature cells.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

27.     What is the abnormal proliferation of cells in response to excessive hormonal stimulation? a. Dysplasia

b.      Pathologic dysplasia

c.       Hyperplasia

d.      Pathologic hyperplasia

 

 

ANS: D

Pathologic hyperplasia is the abnormal proliferation of normal cells and can occur as a response to excessive hormonal stimulation or the effects of growth factors on target cells. Dysplasia refers to abnormal changes in the size, shape, and organization of mature cells. Hyperplasia is an increase in the number of cells in an organ or tissue resulting from an increased rate of cellular division and is a response to prolonged injury.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

28.     Removal of part of the liver leads to the remaining liver cells undergoing which compensatory process?

a.       Atrophy

b.      Metaplasia

c.       Hyperplasia

d.      Dysplasia

 

 

ANS: C

Compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate.

For example, the removal of part of the liver leads to hyperplasia of the remaining liver cells (hepatocytes) to compensate for the loss. The other options do not accurately identify the compensatory process described in the question.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

29.     What is the single most common cause of cellular injury?

a.       Hypoxic injury

b.      Chemical injury

c.       Infectious injury

d.      Genetic injury

 

 

ANS: A

Hypoxia, or lack of sufficient oxygen, is the single most common cause of cellular injury. The other options are not as commonly observed as is the correct option.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

30.     In decompression sickness, emboli are formed by bubbles of what?

a.       Oxygen

b.      Nitrogen

c.       Carbon monoxide

d.      Hydrogen

 

 

ANS: B

If water pressure is too rapidly reduced, the gases dissolved in blood bubble out of the solution, forming emboli. Oxygen is quickly redissolved, but nitrogen bubbles may persist and obstruct blood vessels. Ischemia, resulting from gas emboli, causes cellular hypoxia, particularly in the muscles, joints, and tendons, which are especially susceptible to changes in oxygen supply. The remaining options are not involved in the formation of decompression sickness emboli.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

31.     Which is an effect of ionizing radiation exposure?

a.       Respiratory distress

b.      Sun intolerance

c.       DNA aberrations

d.      Death

 

 

ANS: C

The effects of ionizing radiation may be acute or delayed. Acute effects of high doses, such as skin redness, skin damage, or chromosomal aberrations, occur within hours, days, or months. The delayed effects of low doses may not be evident for years. The other options are not commonly considered effects of radiation exposure.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

32.     What is dysplasia?

a.       Abnormal increase in the number of a specific cell type

b.      True adaptive process at the cellular level

c.       Modification in the shape of a specific cell type

d.      Lack of oxygen at the cellular level

 

 

ANS: C

Dysplasia refers only to abnormal changes in the size, shape, and organization of mature cells, not an increase in number. Dysplasia is not a true adaptive change and is not due to lack of oxygen at the cellular level.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

MULTIPLE RESPONSE

 

1.      Which organs are affected by lead consumption? (Select all that apply.) a. Bones

b.      Muscles

c.       Pancreas

d.      Nerves

e.       Eyes

 

 

ANS: A, D

The organ systems that are primarily affected by lead include the nervous system, bones, kidneys, teeth, cardiovascular, and reproductive and immune systems.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

2.      A healthcare professional is screening children for fetal alcohol syndrome. Which children would the professional assess as possibly suffering from this disorder? (Select all that apply.) a. Frequent asthma attacks

b.      Cognitive impairment

c.       Short stature for age

d.      Esophageal stricture

e.       Facial anomalies

 

 

ANS: B, C, E

Fetal alcohol syndrome (FAS) can lead to specific facial abnormalities, growth deficits, and CNS abnormalities. The children displaying these signs should be suspected of having FAS. FAS does not cause asthma or esophageal strictures.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

3.      What organs are affected by the type of necrosis that results from either severe ischemia or chemical injury? (Select all that apply.) a. Lungs

b.      Brain

c.       Kidneys

d.      Muscles

e.       Heart

 

 

ANS: C, E

Coagulative necrosis, which occurs primarily in the kidneys, heart, and adrenal glands, is a common result of hypoxia from severe ischemia or hypoxia caused by chemical injury, especially the ingestion of mercuric chloride. The other options do not accurately identify organs affected by necrosis resulting from ischemia or chemical injury.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

4.      Which statements are true about melanin? (Select all that apply.)

a.       Rarely found in epithelial cells

b.      Found in cells called keratinocytes, which are present in the retina

c.       A factor in the prevention of certain types of cancer

d.      Most influential in managing the effects of short-term sunlight exposure

e.       Accumulates in specific cells found in the skin

 

 

ANS: B, C, E

Melanin accumulates in epithelial cells (keratinocytes) of the skin and retina and is an extremely important pigment because it protects the skin against long exposure to sunlight and is considered an essential factor in the prevention of skin cancer. Melanin is found in epithelial cells and is not most influential in managing the effects of short-term sunlight exposure.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

5.      What are examples of adaptive cellular responses? (Select all that apply.) a. Atrophy

b.      Dysplasia

c.       Hypertrophy

d.      Hyperplasia

e.       Metaplasia

 

 

ANS: A, C, D, E

Atrophy, hypertrophy, hyperplasia, and metaplasia are considered to be adaptive cellular responses. Dysplasia is not a true adaptive response.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

6.      What are examples of blunt force injuries? (Select all that apply.)

a.       Bruise to the upper arm, resulting from a fall

b.      Simple tibia fracture sustained in a skiing accident

c.       Cut on the finger while slicing vegetables for a salad

d.      Spleen laceration caused by a punch during a physical fight

e.       Small caliber gunshot wound to the foot while target shooting

 

 

ANS: A, B, D

Blunt force injuries are the result of tearing, shearing, or crushing types of injuries, resulting in bruises, fractures, and lacerations caused by blows or impacts. Knife wounds and gunshot wounds are considered penetrating injuries.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

7.      Which statements are true regarding the effects of marijuana use? (Select all that apply.)

a.       Beneficial effects include decreases in nausea and pain.

b.      Heavy use can result in psychomotor impairments.

c.       Possibly causes reproductive changes

d.      Research does not support marijuana use as a factor in developing lung cancer.

e.       Fetal development appears to be unharmed by marijuana use.

 

 

ANS: A, B, C

Marijuana’s effects include psychomotor impairments with heavy use, possible lung cancer (dose not determined), and fetal developmental effects. Reproductive changes have been seen in animal studies and may occur in humans. Beneficial effects include a decrease in nausea and chronic pain.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

Chapter 03: The Cellular Environment: Fluids and Electrolytes, Acids and Bases

 

MULTIPLE CHOICE

 

1.         Why are infants most susceptible to significant losses in total body water?

a.       High body surface-to-body size ratio

b.      Slow metabolic rate

c.       Kidneys are not mature enough to counter fluid losses

d.      Inability to communicate adequately when he or she is thirsty

 

 

ANS: C

Renal mechanisms that regulate fluid and electrolyte conservation are often not mature enough to counter the losses; consequently, dehydration may rapidly develop. Infants can be susceptible to changes in total body water because of their high metabolic rate and the turnover of body fluids caused by their greater body surface area in proportion to their total body size. An infant’s ability to communicate is limited and caregivers must become adept at reading their signals.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

2.         Why does obesity create a greater risk for dehydration in people?

a.       Adipose cells contain little water because fat is water repelling.

b.      The metabolic rate of obese adults is slower than the rate of lean adults.

c.       The rate of urine output of obese adults is higher than in lean adults.

d.      The thirst receptors of the hypothalamus do not function effectively.

 

 

ANS: A

The percentage of total body water (TBW) varies with the amount of body fat and age. Because fat is water repelling (hydrophobic), very little water is contained in adipose cells. Individuals with more body fat have proportionately less TBW and tend to be more susceptible to fluid imbalances that cause dehydration.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

3.         A patient’s blood gases reveal the following findings: pH 7.3; bicarbonate (HCO3) 27 mEq/L; carbon dioxide (CO2) 58 mm Hg. What is the interpretation of these gases? a. Respiratory alkalosis

b.      Metabolic acidosis

c.       Respiratory acidosis

d.      Metabolic alkalosis

 

 

ANS: C

The values provided in this question characterize only acute uncompensated respiratory acidosis. Respiratory acidosis is characterized by a low pH and high CO2. Alkalosis is characterized by higher than normal pH. A metabolic acidosis would have a lower than normal pH with a bicarbonate concentration of <22 mEq/L.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

4.         Water movement between the intracellular fluid (ICF) compartment and the extracellular fluid (ECF) compartment is primarily a function of what? a. Osmotic forces

b.      Plasma oncotic pressure

c.       Antidiuretic hormone

d.      Hydrostatic forces

 

 

ANS: A

The movement of water between the ICF and ECF compartments is primarily a function of osmotic forces.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

5.         In addition to osmosis, what force is involved in the movement of water between the plasma and interstitial fluid spaces? a. Oncotic pressure

b.      Buffering

c.       Net filtration

d.      Hydrostatic pressure

 

 

ANS: D

Water moves between the plasma and interstitial fluid through the forces of only osmosis and hydrostatic pressure, which occur across the capillary membrane. Buffers are substances that can absorb excessive acid or base to minimize pH fluctuations. Net filtration is a term used to identify fluid movement in relationship to the Starling hypothesis. Oncotic pressure encourages water to cross the barrier of capillaries to enter the circulatory system.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

6.         Venous obstruction is a cause of edema because of an increase in which pressure? a. Capillary hydrostatic

b.      Interstitial hydrostatic

c.       Capillary oncotic

d.      Interstitial oncotic

 

 

ANS: A

Venous obstruction can increase the hydrostatic pressure of fluid in the capillaries enough to cause fluid to escape into the interstitial spaces. The remaining options are not causes of edema resulting from venous obstruction.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

7.         At the arterial end of capillaries, why does fluid move from the intravascular space into the interstitial space?

a.       Interstitial hydrostatic pressure is higher than the capillary hydrostatic pressure.

b.      Capillary hydrostatic pressure is higher than the capillary oncotic pressure.

c.       Interstitial oncotic pressure is higher than the interstitial hydrostatic pressure.

d.      Capillary oncotic pressure is lower than the interstitial hydrostatic pressure.

 

 

ANS: B

At the arterial end of capillaries, fluid moves from the intravascular space into the interstitial because capillary hydrostatic pressure is higher than the capillary oncotic pressure.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

8.         Low plasma albumin causes edema as a result of a reduction in which pressure? a. Capillary hydrostatic

b.      Interstitial hydrostatic

c.       Plasma oncotic

d.      Interstitial oncotic

 

 

ANS: C

Albumin is the plasma protein that is primarily responsible for the plasma oncotic pressure because it has the highest concentration. Therefore a low concentration of albumin would lower the plasma oncotic pressure, leading to edema.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

9.         How are secretion of antidiuretic hormone (ADH) and the perception of thirst stimulated? a. Decrease in serum sodium

b.      Increase in plasma osmolality

c.       Increase in glomerular filtration rate

d.      Decrease in osmoreceptor stimulation

 

 

ANS: B

Secretion of ADH and the perception of thirst are primary factors in the regulation of water balance. Thirst is a sensation that stimulates water-drinking behavior. Thirst is experienced when water loss equals 2% of an individual’s body weight or when osmotic pressure increases. A decrease in serum sodium would have the opposite effect. Increased glomerular filtration and decreased osmoreceptor stimulation would not lead to secretion of ADH and the feeling of thirst.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

10.     Thirst activates osmoreceptors following an increase in which blood plasma component? a. Antidiuretic hormone

b.      Aldosterone

c.       Hydrostatic pressure

d.      Osmotic pressure

 

 

ANS: D

Thirst is experienced when water loss equals 2% of an individual’s body weight or when osmotic pressure increases. Dry mouth, hyperosmolality, and plasma volume depletion activate osmoreceptors (neurons located in the hypothalamus that are stimulated by increased osmotic pressure). Increased antidiuretic hormone, aldosterone, and hydrostatic pressure do not activate osmoreceptors.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

11.     A student asks about natriuretic peptides. Which statement by the professor is most accurate?

a.       Decrease blood pressure and increase sodium and water excretion.

b.      Increase blood pressure and decrease sodium and water excretion.

c.       Increase heart rate and decrease potassium excretion.

d.      Decrease heart rate and increase potassium excretion.

 

 

ANS: A

Natriuretic peptides are hormones that include atrial natriuretic peptide (ANP) produced by the myocardial atria, brain natriuretic peptide (BNP) produced by the myocardial ventricles, and urodilatin within the kidney. Natriuretic peptides decrease blood pressure and increase sodium and water excretion. They do not increase blood pressure, decrease sodium and water excretion, directly affect heart rate, or change potassium excretion.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

12.     When changes in total body water are accompanied by proportional changes in electrolytes, what type of alteration occurs? a. Isotonic

b.      Hypertonic

c.       Hypotonic

d.      Normotonic

 

 

ANS: A

Isotonic alterations occur when proportional changes in electrolytes and water accompany changes in total body water leaving osmolality unchanged. Hypertonic changes develop when the osmolality of the ECF is elevated higher than normal. Hypotonic changes occur when the osmolality of the ECF is lower than normal. Normotonic is not a description of changes in body water.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

13.     Which enzyme is secreted by the juxtaglomerular cells of the kidney when circulating blood volume is reduced? a. Angiotensin I

b.      Angiotensin II

c.       Aldosterone

d.      Renin

 

 

ANS: D

When circulating blood volume or blood pressure is reduced, renin, an enzyme secreted by the juxtaglomerular cells of the kidney, is released in response to sympathetic nerve stimulation and decreased perfusion of the renal vasculature. Renin stimulates the formation of angiotensin I, which is an inactive polypeptide, In the presence of angiotensin-converting enzyme, angiotensin I is transformed into angiotensin II, which is a potent vasoconstrictor. Aldosterone promotes sodium and water reabsorption by the kidneys.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

14.     A patient in the hospital has hypernatremia. What condition should the healthcare professional assess for?

a.       Syndrome of inappropriate antidiuretic hormone

b.      Hypersecretion of aldosterone

c.       Brief bouts of vomiting or diarrhea

d.      Excessive diuretic therapy

 

 

ANS: B

Hypernatremia occurs because of (1) inadequate free water intake, (2) inappropriate administration of hypertonic saline solution (e.g., sodium bicarbonate for treatment of acidosis during cardiac arrest), (3) high sodium levels as a result of oversecretion of aldosterone (as in primary hyperaldosteronism), or (4) Cushing syndrome (caused by the excess secretion of adrenocorticotropic hormone [ACTH], which also causes increased secretion of aldosterone). The other options do not result in hypernatremia. The healthcare professional should assess the patient for hypersecretion of aldosterone.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

15.     A patient has a serum sodium level of 165 mEq/L. The healthcare professional explains that the clinical manifestations of confusion, convulsions, cerebral hemorrhage, and coma are caused by what mechanism?

a.       High sodium in the blood vessels pulls water out of the brain cells into the blood vessels, causing brain cells to shrink.

b.      High sodium in the brain cells pulls water out of the blood vessels into the brain cells, causing them to swell.

c.       Low sodium in the blood vessels pulls potassium out of the brain cells, which slows the synapses in the brain.

d.      Low sodium in the blood vessels draws chloride into the brain cells followed by water, causing the brain cells to swell.

 

 

ANS: A

A normal serum sodium level is 135 to 145 mEq/L so this patient’s level is high. Hypernatremia causes manifestations by pulling water out of the brain cells into the blood vessels.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

16.     What does vomiting-induced metabolic alkalosis cause?

a.       Retained sodium to bind with the chloride

b.      Hydrogen to move into the cell and exchange with potassium

c.       Retention of bicarbonate to maintain the anion balance

d.      Hypoventilation to compensate for the metabolic alkalosis

 

 

ANS: C

When vomiting with the depletion of ECF and chloride (hypochloremic metabolic alkalosis) causes acid loss, renal compensation is not effective; the volume depletion and loss of electrolytes (sodium [Na+], potassium [K+], hydrogen [H+], chlorine [Cl–]) stimulate a paradoxic response by the kidneys. The kidneys increase sodium and bicarbonate reabsorption with the excretion of hydrogen. Bicarbonate is reabsorbed to maintain an anionic balance because the ECF chloride concentration is decreased. Metabolic alkalosis will not lead to retained sodium, hydrogen movement into the cell, or hypoventilation.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

17.     The pathophysiologic process of edema is related to which mechanism?

a.       Sodium depletion

b.      Decreased capillary hydrostatic pressure

c.       Increased plasma oncotic pressure

d.      Lymphatic obstruction

 

 

ANS: D

The pathophysiologic process of edema is related to an increase in the forces favoring fluid filtration from the capillaries or lymphatic channels into the tissues. The most common mechanisms are increased capillary hydrostatic pressure, decreased plasma oncotic pressure, increased capillary membrane permeability and lymphatic obstruction, and sodium retention.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

18.     Why is insulin used to treat hyperkalemia?

a.       Stimulates sodium to be removed from the cell in exchange for potassium

b.      Binds to potassium to remove it through the kidneys

c.       Transports potassium from the blood into the cell along with glucose

d.      Breaks down the chemical components of potassium, inactivating it

 

 

ANS: C

Insulin promotes the uptake of K+ by stimulating the Na+-K+-ATPase pump. It does not stimulate the removal of sodium from the cell nor does it bind to K+ to excrete it. The Na+-K+-ATPase pump does facilitate movement of K+ into liver and muscle cells along with glucose to regulate blood glucose after eating.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

19.     A major determinant of the resting membrane potential necessary for the transmission of nerve impulses is the ratio between what?

a.       Intracellular and extracellular Na+

b.      Intracellular and extracellular K+

c.       Intracellular Na+ and extracellular K+

d.      Intracellular K+ and extracellular Na+

 

 

ANS: B

The ratio of K+ in the ICF to K+ in the ECF is the major determinant of the resting membrane potential, which is necessary for the transmission and conduction of nerve impulses, for the maintenance of normal cardiac rhythms, and for the skeletal and smooth muscle contraction. This is not true of the other options.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

20.     During acidosis, the body compensates for the increase in serum hydrogen ions by shifting hydrogen ions into the cell in exchange for which electrolyte? a. Oxygen

b.      Sodium

c.       Potassium

d.      Magnesium

 

 

ANS: C

In states of acidosis, hydrogen ions shift into the cells in exchange for intracellular fluid potassium; hyperkalemia and acidosis therefore often occur together. This is not true of the other options.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

21.     A healthcare professional is caring for four patients. Which patient should the professional assess for hyperkalemia?

a.       Hyperparathyroidism

b.      Vomiting

c.       Renal failure

d.      Hyperaldosteronism

 

 

ANS: C

Hyperkalemia should be investigated when a history of renal disease, massive trauma, insulin deficiency, Addison disease, use of potassium salt substitutes, or metabolic acidosis exists. Hyperparathyroidism might lead to hyperphosphatemia. Vomiting is frequently associated with potassium depletion. Hyperaldosteronism also can lead to potassium wasting.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

22.     In hyperkalemia, what change occurs to the cells’ resting membrane potential? a. Hypopolarization

b.      Hyperexcitability

c.       Depolarization

d.      Repolarization

 

 

ANS: A

In hyperkalemia, the cells’ resting membrane potential becomes more positive (i.e., changes from –90 to –80 mV) and the cell membrane is hypopolarized (i.e., the inside of the cell becomes less negative or partially depolarized).

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

23.     A patient’s chart indicates Kussmaul respirations. The student asks the healthcare professional what this is caused by. What response by the professional is most accurate?

a.       Anxiety leads to Kussmaul respirations and is a cause of respiratory acidosis.

b.      A compensatory measure is needed to correct metabolic acidosis.

c.       Diabetic ketoacidosis is leading to metabolic acidosis.

d.      More oxygen is necessary to compensate for respiratory acidosis.

 

 

ANS: B

Deep, rapid respirations (Kussmaul respirations) are indicative of respiratory compensation for metabolic acidosis. Anxiety would lead to respiratory alkalosis as carbon dioxide is blown off by the lungs. Kussmaul’s respirations may be seen in diabetic ketoacidosis, but they do not diagnose it. Kussmaul’s respirations are not present in respiratory acidosis.

 

                PTS: 1                     DIF: Cognitive Level: Comprehension

 

24.     A healthcare provider notes that tapping the patient’s facial nerve leads to lip twitching. What electrolyte value is correlated with this finding? a. K+: 2.8 mEq/L

b.      K+: 5.4 mEq/L

c.       Ca++: 8.2 mg/dL

d.      Ca++: 12.9 mg/dL

 

 

ANS: C

This patient has a positive Chvostek sign, which is indicative of hypocalcemia. The normal range of Ca++ is 9 to 10.5 mg/dL. 12.9 mg/dL indicates hypercalcemia. Potassium imbalances are not related.

 

                PTS: 1                      DIF: Cognitive Level: Analyzing

 

25.     A patient has a history of excessive use of magnesium-containing antacids and aluminumcontaining antacids. What lab value does the healthcare professional correlate to this behavior? a. Magnesium 1.8 mg/dL

b.      Phosphate 1.9 mg/dL

c.       Sodium 149 mEq/L

d.      Potassium 2.5 mEq/L

 

 

ANS: B

Excessive use of magnesium-containing and aluminum-containing antacids can lead to hypophosphatemia, which is a serum level less than 2 mg/dL. The magnesium level is normal, but magnesium is not related. The sodium level is high, but that is not related. The potassium level is low, but this is also not related.

 

                PTS: 1                      DIF: Cognitive Level: Analyzing

 

26.     A healthcare professional is caring for four patients. Which patient should the professional assess for hypermagnesemia as a priority? a. Hepatitis

b.      Renal failure

c.       Trauma to the hypothalamus

d.      Pancreatitis

 

 

ANS: B

Renal failure usually causes hypermagnesemia, in which magnesium concentration is greater than 2.5 mEq/L. Hypermagnesemia is not a result of the other options.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

27.     Physiologic pH is maintained at approximately 7.4 because bicarbonate (HCO3) and carbonic acid (H2CO3) exist in what ratio? a. 20:1

b.      1:20

c.       10:2

d.      10:5

 

 

ANS: A

The relationship between HCO3 and H2CO3 is usually expressed as a ratio. When the pH is 7.4, this ratio is 20:1 (HCO3:H2CO3). The other options do not accurately identify physiologic pH by the correct ratio of HCO3 and H2CO3.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

28.     Where is two thirds of the body’s water found?

a.       Interstitial fluid spaces

b.      Vascular system

c.       Intracellular fluid compartments

d.      Intraocular fluids

 

 

ANS: C

Two thirds of the body’s water is in the intracellular fluid (ICF) compartment, and one third is in the extracellular fluid (ECF) compartment. The two main ECF compartments are the interstitial fluid and the intravascular fluid, which is the blood plasma. Other ECF compartments include the lymph and the transcellular fluids, such as the synovial, intestinal, biliary, hepatic, pancreatic, and cerebrospinal fluids; sweat; urine; and pleural, synovial, peritoneal, pericardial, and intraocular fluids.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

29.     A healthcare professional just administered a large dose of insulin to a patient. Which electrolyte value should the professional monitor as a priority? a. Sodium

b.      Potassium

c.       Calcium

d.      Magnesium

 

 

ANS: B

Insulin contributes to the regulation of plasma potassium levels by stimulating the Na+, K+ATPase pump, thereby promoting the movement of potassium into the cells. The professional should monitor this patient’s potassium level as a priority. The other electrolytes are not directly influenced by insulin administration.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

30.     Why does increased capillary hydrostatic pressure result in edema?

a.       Losses or diminished production of plasma albumin

b.      Inflammation resulting from an immune response

c.       Blockage within the lymphatic channel system

d.      Sodium and water retention

 

 

ANS: D

Increased capillary hydrostatic pressure can result from venous obstruction or sodium and water retention. The other options do not accurately describe the cause of edema related to increased capillary hydrostatic pressure.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

31.     A patient’s electrocardiogram (ECG) shows tall, peaked T waves. What lab value or assessment would the healthcare professional correlate with this finding? a. Positive Chvostek sign

b.      Serum potassium 6.7 mEq/L

c.       Nausea and vomiting

d.      Serum sodium 138 mEq/L

 

 

ANS: B

Tall peaked T waves on an ECG are indicative of hyperkalemia. Normal potassium is 3.5 to 5.0 mEq/L. A positive Chvostek sign is indicative of hypocalcemia. Nausea and vomiting are not related.

 

                PTS: 1                      DIF: Cognitive Level: Analyzing

 

MULTIPLE RESPONSE

 

1.         Which groups are at risk for fluid imbalance? (Select all that apply.)

a.       Women

b.      Infants

c.       Men

d.      Obese persons

e.       Older adults

 

 

ANS: B, D, E

Kidney function, surface area, total body water, and the hydrophobic nature of fat cells all contribute to the increased risk for fluid imbalance among obese individuals, infants, and older adults. Gender alone is not a risk factor for fluid imbalance.

 

                PTS: 1                     DIF:   Cognitive Level: Knowledge

 

2.         A patient is admitted to the hospital with dehydration. For which signs or symptoms would the healthcare professional assess? (Select all that apply.) a. Moist mucous membranes

b.      Weak pulses

c.       Tachycardia

d.      Polyuria

e.       Weight loss

 

 

ANS: B, C, E

Symptoms of dehydration include weak pulses, tachycardia, and weight loss among others. Moist mucus membranes are normal and indicate normal fluid balance. Polyuria would indicate either a disease state or fluid volume overload.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

3.         What are the causes of hypocalcemia? (Select all that apply.)

a.       Repeated blood administration

b.      Pancreatitis

c.       Decreased reabsorption of calcium

d.      Hyperparathyroidism

e.       Kidney stones

 

 

ANS: A, B

Blood transfusions are a common cause of hypocalcemia because the citrate solution used in storing whole blood binds with calcium. Pancreatitis causes a release of lipases into soft-tissue spaces; consequently, the free fatty acids that are formed bind calcium, causing a decrease in ionized calcium. The other options are not recognized causes of hypocalcemia.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

4.         A patient is admitted with hyponatremia. For which clinical manifestations would the healthcare professional assess? (Select all that apply.) a. Headache

b.      Seizures

c.       Paranoia

d.      Confusion

e.       Lethargy

 

 

ANS: A, B, D, E

Behavioral and neurologic changes characteristic of hyponatremia include lethargy, headache, confusion, apprehension, seizures, and coma. Paranoia is not associated with hyponatremia.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

5.         A patient has been diagnosed with hypercalcemia. Which manifestations does the healthcare professional assess for? (Select all that apply.) a. Diarrhea

b.      Calcium-based kidney stones

c.       ECG showing narrow T waves

d.      Lethargy

e.       Bradycardia

 

 

ANS: B, D, E

Fatigue, weakness, lethargy, anorexia, nausea, and constipation are common. Behavioral changes may occur. Impaired renal function frequently develops, and kidney stones form as precipitates of calcium salts. A shortened QT segment and depressed widened T waves also may be observed on the ECG, with bradycardia and varying degrees of heart block.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

6.         A patient’s serum potassium level is 2.7 mEq/L. Which clinical manifestations does the healthcare professional assess for? (Select all that apply.) a. Paralytic ileus

b.      Sinus bradycardia

c.       Atrioventricular block

d.      Dry mucous membranes

e.       Tetany

 

 

ANS: A, B, C

Normal potassium level is 3.5 to 5.0 mEq/L so this patient has hypokalemia. A variety of dysrhythmias may occur, including sinus bradycardia, atrioventricular block, paroxysmal atrial tachycardia, and paralytic ileus. The other options are not related to hypokalemia.

 

                PTS: 1                      DIF: Cognitive Level: Analyzing

 

7.         A third of the body’s fluid is contained in the extracellular interstitial fluid spaces that include what? (Select all that apply.) a. Urine

b.      Intraocular fluids

c.       Lymph

d.      Blood plasma

e.       Sweat

 

 

ANS: A, B, C, E Two thirds of the body’s water is in the intracellular fluid (ICF) compartment, and one third is in the extracellular fluid (ECF) compartments. The two main ECF compartments are the interstitial fluid and the intravascular fluid, such as the blood plasma. Interstitial ECF compartments include the lymph and the transcellular fluids, such as the synovial, intestinal, biliary, hepatic, pancreatic, and cerebrospinal fluids; sweat; urine; and pleural, synovial, peritoneal, pericardial, and intraocular fluids.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

8.         An imbalance of potassium can produce which dysfunctions? (Select all that apply.)

a.       Weakness of skeletal muscles

b.      Cardiac dysrhythmias

c.       Smooth muscle atony

d.      Visual impairment

e.       Hearing loss

 

 

ANS: A, B, C

Symptoms of hyperkalemia vary, but common characteristics are muscle weakness or paralysis and dysrhythmias with changes in the ECG. A wide range of metabolic dysfunctions may result from hypokalemia. Neuromuscular excitability is decreased, causing skeletal muscle weakness, smooth muscle atony, and cardiac dysrhythmias. Potassium imbalances do not produce visual or hearing problems.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

9.         Which statements regarding total body water (TBW) are true? (Select all that apply.)

a.       During childhood, TBW slowly decreases in relationship to body weight.

b.      Gender has no influence on TBW until old age.

c.       Men tend to have greater TBW as a result of their muscle mass.

d.      Estrogen plays a role in female TBW.

e.       Older adults experience a decrease in TBW as a result of decreased muscle mass.

 

 

ANS: A, C, D, E

During childhood, TBW slowly decreases to 60% to 65% of body weight. At adolescence, the percentage of TBW approaches adult proportions, and gender differences begin to appear. Men eventually have a greater percentage of body water as a function of increasing muscle mass. Women have more body fat and less muscle as a function of estrogens and therefore have less body water. With increasing age, the percentage of TBW declines further still. The decrease is caused, in part, by an increased amount of fat and a decreased amount of muscle, as well as by a reduced ability to regulate sodium and water balance.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

 

10.     The calcium and phosphate balance is influenced by which three substances? (Select all that apply.)

a.       Parathyroid hormone

b.      Vasopressin

c.       Thyroid hormone

d.      Calcitonin

e.       Vitamin D

 

 

ANS: A, D, E

Three hormones regulate calcium and phosphate balance: parathyroid hormone (PTH), vitamin D, and calcitonin. Vasopressin and thyroid hormone do not influence calcium and phosphate balance.

 

                PTS: 1                      DIF: Cognitive Level: Knowledge

Chapter 04: Genes and Genetic Diseases

 

MULTIPLE CHOICE

 

1.         In somatic cell gene therapy, what type of vector is most commonly used to alter a specific set of an individual’s somatic cells? a. Virus

b.      Bacteria

c.       RNA polymerase

d.      Recombinant DNA

 

 

ANS: A

In somatic cell gene therapy, a vector is used to carry a normal copy of the mutated gene into the individual’s cells. These vectors are usually viruses, such as retroviruses, lentiviruses, or adenoviruses, which have been genetically modified so that they contain the normal human gene and cannot make copies of themselves (otherwise they could cause a viral infection). Bacteria, RNA polymerase, and recombinant DNA are not used as vectors in somatic cell gene therapy.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

2.         In DNA replication, what does the enzyme DNA polymerase do?

a.       Travel along the single DNA strand, adding the correct nucleotide to the new strand

b.      Move along the double strand of DNA to unwind the nucleotides of the double helix

c.       Hold the double strand apart while the correct nucleotides are added to the strand

d.      Transport the double strand of DNA from the nucleus to the cytoplasm for protein formation

 

 

ANS: A

The DNA polymerase enzyme travels along the single DNA strand, adding the correct nucleotides to the free end of the new strand (see Figure 4-3, B). The correct option is the only one that accurately describes the process involved in DNA replication using DNA polymerase.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

3.         How is transcription best defined?

a.       DNA polymerase binds to the promoter site on ribonucleic acid (RNA).

b.      RNA directs the synthesis of polypeptides for protein synthesis.

c.       RNA is synthesized from a DNA template.

d.      A base pair substitution results in a mutation of the amino acid sequence.

 

 

ANS: C

Transcription is the process by which RNA is synthesized from a DNA template. The correct option is the only one that accurately defines the term transcription.

 

                PTS: 1                     DIF:   Cognitive Level: Remembering

 

4.         What is the purpose of using a Giemsa staining technique on chromosomes?

a.       Permit the mitotic process to be followed and monitored for variations.

b.      Allow for the numbering of chromosomes and the identification of variations.

c.       Identify new somatic cells formed through mitosis and cytokinesis.

d.      Distinguish the sex chromosomes from the homologous chromosomes.

 

 

ANS: B

One of the most commonly used stains is Giemsa stain. By using banding techniques, chromosomes can be unambiguously numbered, and individual variation in chromosome composition can be studied. Missing or duplicated portions of chromosomes, which often result in serious diseases, also can be readily identified. The correct option is the only one that accurately describes the purpose of the Giemsa staining technique.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

5.         An amniocentesis indicates a neural tube defect when an increase in which protein is evident? a. Cytochrome P-450

b.      Alpha fetoprotein

c.       DNA polymerase

d.      Embryonic proteins

 

 

ANS: B

Other disorders can be detected with this procedure. These include most neural tube defects, which cause an elevation of alpha fetoprotein in the amniotic fluid, and hundreds of diseases caused by mutations of single genes. Cytochrome P-450 is useful in helping to formulate drug doses more precisely. DNA polymerase travels along the single DNA strand, adding the correct nucleotides to the free end of the new strand during DNA replication. Embryonic proteins are not involved in neural tube defects.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

6.         Amniocentesis is recommended for pregnant with what history?

a.       Have a history of chronic illness

b.      Have a family history of genetic disorders

c.       Have experienced in vitro fertilization

d.      Had a late menarche

 

 

ANS: B

Amniocentesis is recommended only for pregnancies known to have an elevated risk for a genetic disease or in women older than 30 to 35 years of age because of the slightly higher risk of fetal loss as compared to the general population. Having a chronic illness, previous in vitro fertilization, or late menarche are not reasons to have an amniocentesis.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

7.         What is the technique for prenatal diagnosis of chromosomal abnormalities at 10 to 12 weeks’ gestation?

a.       Gene mapping

b.      Linkage analysis

c.       Amniocentesis

d.      Chorionic villus sampling

 

 

ANS: D

Chorionic villus sampling consists of extracting a small amount of villous tissue directly from the chorion. This procedure can be performed at 10 weeks’ gestation and does not require in vitro culturing of cells; sufficient numbers are directly available in the extracted tissue. Thus the procedure allows prenatal diagnosis at approximately 3 months’ gestation rather than at nearly 4 months’ gestation which is generally when amniocentesis is performed. Gene mapping and linkage analysis are not performed exclusively on women who are 10 weeks’ pregnant.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

8.         What is the term for an error in which homologous chromosomes fail to separate during meiosis or mitosis?

a.       Aneuploidy

b.      Nondisjunction

c.       Polyploidy

d.      Translocation

 

 

ANS: B

Aneuploidy is usually the result of nondisjunction, an error in which homologous chromosomes or sister chromatids fail to separate normally during meiosis or mitosis. Aneuploidy refers to cells that do not contain a multiple of 23 chromosomes. Polyploidy is when a cell has more than the diploid number of chromosomes, it is said to be a polyploid cell. Translocation refers the interchanging of genetic material between nonhomologous chromosomes.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

9.         A healthcare professional is assessing a child who has complete trisomy of the twenty-first chromosome. What findings does the professional relate to this condition?

a.       Widely spaced nipples, reduced carrying angle at the elbow, and sparse body hair

b.      An IQ of 25 to 70, low nasal bridge, protruding tongue, and flat, low-set ears

c.       High-pitched voice, tall stature, gynecomastia, and an IQ of 60 to 90

d.      Circumoral cyanosis, edema of the feet, short stature, and mental slowness

 

 

ANS: B

This child has Trisomy 21, also known as Down syndrome. These children typically present with IQs ranging from 25 to 70. The facial appearance is distinctive and exhibits a low nasal bridge, epicanthal folds, protruding tongue, and flat, low-set ears. Widely spaced nipples and edema of the newborn’s feet are characteristic of Turner syndrome. The high-pitched voice and gynecomastia are characteristic of Klinefelter syndrome.

 

                PTS: 1                      DIF: Cognitive Level: Applying

 

10.     What is the most common cause of Down syndrome?

a.       Paternal nondisjunction

b.      Maternal translocations

c.       Maternal nondisjunction

d.      Paternal translocation

 

 

ANS: C

Nondisjunction during the formation of one of the parent’s gametes or during early embryonic development occurs in approximately 97% of infants born with Down syndrome. In approximately 90% to 95% of infants, the nondisjunction occurs in the formation of the mother’s egg cell. Down syndrome is rarely caused by paternal nondisjunction. Robertsonian translocations are responsible for 3% to 5% of cases of Down syndrome. A high-pitched voice and gynecomastia are characteristic of Klinefelter syndrome.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

11.     What syndrome, characterized by an absent homologous X chromosome with only a single X chromosome, exhibits features that include a short stature, widely spaced nipples, and webbed neck?

a.       Down

b.      Cri du chat

c.       Turner

d.      Klinefelter

 

 

ANS: C In Turner syndrome, a sex chromosome is missing, and the person’s total chromosome count is 45. Characteristic signs include short stature, female genitalia, webbed neck, shieldlike chest with underdeveloped breasts and widely spaced nipples, and imperfectly developed ovaries. Children with Down syndrome have an IQ of 25 to 70, low nasal bridge, protruding tongue, and flat, low-set ears. Children with Cri du chat have a characteristic cry and other symptoms include low birth weight, severe intellectual disability, microcephaly (smaller than normal head size), heart defects, and a typical facial appearance. A high-pitched voice and gynecomastia are characteristic of Klinefelter syndrome.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

12.     A person with 47, XXY karyotype has the genetic disorder resulting in which syndrome? a. Turner

b.      Klinefelter

c.       Down

d.      Fragile X

 

 

ANS: B

A disorder in the chromosome (47, XXY karyotype) results in a disorder known as Klinefelter syndrome. Turner syndrome has a karyotype of 45, X. Down syndrome is caused by Trisomy 21. Fragile X syndrome is caused by microscopically observable breaks and gaps in the X chromosome.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

13.     What is the second most commonly recognized genetic cause of intellectual disability?

a.       Down syndrome

b.      Fragile X syndrome

c.       Klinefelter syndrome

d.      Turner syndrome

 

 

ANS: B

The fragile X syndrome is the second most common genetic cause of intellectual disability (after Down syndrome). Fragile X, Klinefelter, and Turner syndromes not observed with enough frequency are to be recognized as the second most common cause of intellectual disability.

 

                PTS: 1                      DIF: Cognitive Level: Remembering

 

14.     What is the blood type of a person who is heterozygous, having A and B alleles as codominant? a. A

b.      B

c.       O

d.      AB

 

 

ANS: D

When the heterozygote is distinguishable from both homozygotes, the locus is said to exhibit codominance. An example is the ABO blood group, in which heterozygotes having the A and B alleles express both of them as A and B antigens on their red cells (forming blood group AB). Blood types A, B, and O do not demonstrate codominance.

 

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15.     A couple has two children diagnosed with an autosomal dominant genetic disease and asks the healthcare professional what the probability is that their next child will have the same genetic disease. What response by the professional is best? a. One sixth

b.      One fourth

c.       One third

d.      One half

 

 

ANS: D

Affected heterozygous individuals transmit the trait to approximately one half of their children; however, because gamete transmission is subject to chance fluctuations, it is possible that all or none of the children of an affected parent may have the trait. Nevertheless, when large numbers of matings of this type are studied, the proportion of affected children closely approaches one half.

 

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16.     When a child inherits a disease that is autosomal recessive, it is inherited from whom? a. Father

b.      Mother

c.       Both parents

d.      Grandparent

 

 

ANS: C

In most cases of recessive disease, both parents of affected individuals are heterozygous carriers.

 

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17.     People diagnosed with neurofibromatosis have varying degrees of the condition because of which genetic principle? a. Penetrance

b.      Expressivity

c.       Dominance

d.      Recessiveness

 

 

ANS: B

Expressivity is the extent of variation in phenotype associated with a particular genotype. If expressivity of a disease is variable, then the penetrance may be complete but the severity of the disease can vary greatly. A well-known example of variable expressivity in an autosomal dominant disease is type 1 neurofibromatosis. The penetrance of a trait is the percentage of individuals with a specific genotype who also exhibit the expected phenotype. An allele whose effects are observable is said to be dominant, while one whose effects are hidden is said to be recessive.

 

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18.     Which genetic disease has been linked to a mutation of the tumor-suppressor gene? a. Hemochromatosis

b.      Retinoblastoma

c.       Familial breast cancer

d.      Hemophilia A

 

 

ANS: B

The gene responsible for retinoblastoma has been mapped to the long arm of chromosome 13, and its DNA sequence has been extensively studied. This gene is known as a tumor-suppressor gene; the normal function of its protein product is to regulate the cell cycle so that cells do not grow uncontrollably. Hemochromatosis, familial breast cancer, and hemophilia A are not caused by a mutation of the tumor-suppressor gene.

 

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19.     Cystic fibrosis is caused by what type of gene?

a.       X-linked dominant

b.      X-linked recessive

c.       Autosomal dominant

d.      Autosomal recessive

 

 

ANS: D

Cystic fibrosis is the most common lethal autosomal recessive disease in white children. It is not X linked or dominant.

 

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20.     Which is an important criterion for discerning autosomal recessive inheritance?

a.       Consanguinity is sometimes present.

b.      Females are affected more than males.

c.       The disease is observed in both the parents, as well as in the siblings.

d.      On average, one half of the offspring of the carrier will be affected.

 

 

ANS: A

Consanguinity (“inbreeding”) is often an important characteristic of pedigrees for recessive diseases; relatives share a certain proportion of genes received from a common ancestor. The other statements do no describe a criterion important in autosomal recessive inheritance.

 

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21.     Consanguinity refers to the mating of people in what situation?

a.       Who are unrelated

b.      When one has an autosomal dominant disorder

c.       Having common family relations

d.      When one has a chromosomal abnormality

 

 

ANS: C

Consanguinity refers to the mating of two related individuals, and the offspring of such matings are said to be “      

 

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22.     Males, having only one X chromosome, are said to be what?

a.       Homozygous

b.      Heterozygous

c.       Hemizygous

d.      Ambizygous

 

 

ANS: C

Males, having only one X chromosome, are said to be hemizygous for genes on this chromosome. Homozygous refers to two alleles being identical at a specific locus. When the alleles are not identical at that locus, the individual is said to be heterozygous. Ambizygous is not a term in the text.

 

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23.     Males are more often affected by which type of genetic disease?

a.       Sex-linked dominant

b.      Sex-influenced

c.       Sex-linked

d.      Sex-linked recessive

 

 

ANS: D