Chapter 11 (PART 3)-Anatomy & Physiology Last updated 28 April 2021 0 1357 The operation of Nervous system depends on what? The flow of information through chains of neurons Neurons are functionally connected by ______ Syanpse What is a Synapses? A junction that mediate information transfer from one neuron to another or to an effector cell Where is the Axodendritic? Between axon terminals of one neuron & the dendrites of others Where is the Axosomatic? Between axon terminals of one neuron and soma of others The neuron conducting impulses toward the synapse is the _______ Presynaptic neuron The neuron transmitting the electrical signal away from the synapse is the _____ Postsynaptic neuron The presynaptic neuron ______ the information, and the postsynaptic neuron _______ the information Sends, Receives Most neurons function as both presynaptic and postsynaptic....True of False? TRUE What are the 2 types of Synapse? Chemical & electical What are the most common type of synapse? Chemical What are Chemical Synapse? Synapse that are specialized for release and reception of chemical neurotransmitters What 2 parts are the Chemical Synapse made up of? Synaptic vesicles & Synaptic cleft A synaptic vesicles are filled with what? Neurotransmitters Where is the neurotransmitter receptor region located on the postsynaptic membrane? On dendrite or cell body The synaptic cleft is a fluid filled space that separates what? Presynaptic and postsynaptic membranes Chemical synapses prevent what? A nerve impulse from being directly transmitted from one neuron to another Chemical synapse convert electrical signals to chemical signals that travel across the synapse to the postsynaptic cells, where they are then converted into what? Back into electrical signals Electrical Synapse consist of _____ junctions Gap What are Electrical Synapse? Neurons electrically coupled and transmission that occurs here is very rapid Electrical synapse are joined by gap junctions that connect the ______ of adjacent neurons Cytoplasm Communication is Electrical synapse can be either ___________ or __________ Unidirectional, Bidirectional In adults, Electrical synapses are found where and are responsible for what? Regions of the brain and responsible for certain stereotype movements The Synaptic Cleft prevents nerve impulses from _______ passing from one neuron to the next Directly Transmission across the synaptic clef depends on what?Hint: there are 3 things - Release- Diffusion- Receptor binding of neurotransmitters Synaptic clef ensures unidirectional communication between ______ Neurons In Information Transfer across Chemical Synapses, an Action Potential arrives where? At the axon terminal of presynaptic neuron In Information Transfer across Chemical Synapses, it causes _____________ channels to open, therefore.... Voltage gated Ca2+ In Information Transfer across Chemical Synapses, what type of PROTEIN binds Ca2+ and promotes fusion of synaptic vesicles with axon membrane? Synaptotagmin In Information Transfer across Chemical Synapses, when Ion channels are open, it causes what kind of event? Excitatory or inhibitory Within just a few milliseconds, neurotransmitters effect terminated in one of what 3 ways? - Reuptake-Degradation- Diffusion What is Synaptic Delay? Time needed for neurotransmitter to be released, diffuse across the membrane, and bind to receptors What structure joins two neurons at an electrical synapse? Gap junctions Chemical synapse are either excitatory or inhibitory depending on what? How they affect the membrane potential of the postsynaptic neuron What are the 2 types of postsynaptic potentials? - EPSP (excitatory postsynaptic potentials)-IPSP (inhibitatory postsynaptic potentials) At excitatory synapse, neurotransmitters binding depolarizes the _______ Postsynaptic membrane Neurotransmitters binding open chemically gated channels allows simultaneous flows of? Na+ and K+ in opposite directions EPSP can help trigger what? An action potential is EPSP is of threshold strength If EPSP helps trigger and Action potential, it can spread to _________, triggering an opening of voltage-gated channels and cause an action potential to be generated Axon hillock What is excitatory postsynaptic potentials? Local graded depolarization events that occur at excitatory postsynaptic membranes Each EPSP last only a few milliseconds an then the membrane returns to its _________ Resting potential Inhibitory Synapses ________ postsynaptic neuron's ability to produce an action potential Reduces Inhibitory Synapses makes the membrane more permeable to ____ or ____ K+ or CL- If K+ channels _____, it moves out of the cell Open If Cl- channels open, it moves ____ the cell Into Hyperpolarizing changes in potential are called? Inhibitory postsynaptic potentials If the inner surface of the membrane becomes more negative, what happens to the Action potential? It becomes less likely to "fired" True or false, A single EPSP can induce an Action potential? False EPSP can add together or _____ to influence the activity of a postsynatic neuron Summate IPSP can also summate...True or False? TRUE Most neurons receive both excitatory and inhibitory inputs from thousands of other neurons...True or False? True What are the 2 types of summation that occur? - Temporal- Spatial When does Temporal summation occur? When one or more presynaptic neurons transmit impulses in rapid-fire order When does Spatial summation occur? When the postsynaptic neuron is stimulated simultaneously by a large number of terminals at the same time Why are the most effective synapses those closest to the axon hillock? Because EPSP and IPSP are graded potentials that decay the farther they spread What is Synaptic Potentiation? Repeated or continuous use of a synapse that enhances the presynaptic neuron's ability to excite the postsynaptic neuron, producing a large EPSP Ca2+ concentrations _____ in presynaptic terminal and postsynaptical neruons Increases Chemically gated channels allow _____ to enter Ca2+ Ca2+ activates ________ that promote more effective responses to subsequent stimuli Kinase enzymes When does Presynaptic inhibition occur? When the release of excitatory neurotransmitters by one is inhibited by another neuron via axoaxonic synapse The less neurons released, the ______ EPSPs formed Smaller 50 or more neurotransmitters have been identified....True or False? TRUE Most neurons make two or more neurotransmitters....True or False? TRUE Different neurotransmitters are released at different stimulation frequencies...True or False? TRUE How are Neurotransmitters classified? By chemical structure and function Neurotransmitters are grouped into several classes based on _________ Molecular structure What was the first neurotransmitter identified? Acetylcholine Where is Acetylcholine released? At neuromuscular junctions Acetylcholine is degraded by what enzyme? Acetylcholinesterase Acetylcholine is released by all neurons that stimulate skeletal muscles and by many neurons of the autonomuc nervous system...True or False? TRUE The Biogenic amines includes? Catecholamines (such as Dopamine) Biogenic amines are broadly distributed in the _____ Brain Biogenic amines play a role in ________ emotional behaviours Amino acids include: - Glutamante- GABA Neurotransmitters have a great diversity of ______ Functions Neurotransmitters can be classified by? - Effects- Actions Effects are ______ vs _______ Excitatory, Inhibitory Actions are ____ vs ____ Direct, Indirect The effect is determined by? The receptor to which it binds ACh is _______ at a neuromuscular junction in skeletal muscle Excitatory ACh is ______ inhibitory in cardiac muscle Inhibitory Neurotransmitter that act directly are those that.... Bind to and open ion channels Direct action of a neurotransmitter promotes rapid responses by altering membrane potential....True or False? TRUE What does Neuromodulator mean? Term used to describe a chemical messenger relased by a neuron that does not directly cause EPSP or IPSP What are the 2 types of Neurotransmitter receptors? - Channel-linked receptors- G protein-linked receptors What are channel-linked receptors? Ligand-gated ion channels that mediate direct neurotransmitter action What are G protein-linked receptors? The responses are indirect, complex, slow Do Neurons function in groups? YES What is Discharge zone? Neurons most closely associated with incoming fiber What is Facilitated zone? Neurons farther away from incoming fiber What are Circuits? Patterns of synaptic connections in neuronal pools What are the 4 types of Circuits? - Diverging- Converging- Reverberating- Parallel after-discharge What do Patterns of Neural Processing do? Input travels along one pathway to a specific destination Why are Patterns of Neural Processing important? For higher-level mental functioning Share this post
0
1357