Anp 1106 Neurophysiology Updated Actual Questions And Correct Answers

ANP 1106 NEUROPHYSIOLOGY UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS

Question:
1. what is the NS subdivided into?

Answer:
1. the CNS: includes the brain and spinal cords
2. PNS: includes the nerves formed of axons that transmit efferent info to the
muscles (somatic NS) or to the internal organs (autonomic NS)
- also includes the afferent axons that transmit sensory info towards CNS

Question:
2. Explain how the ionotropic receptor works (synapsis)

Answer:
- Once in the presynaptic terminal, the AP triggers the opening of Ca voltage-
gated channels
- this allows the entry of Ca to serve as a second for the release of NTs into
synaptic cleft
- the NT is the synaptic cleft binds to a post-synaptic ionotropic receptor of a
ligand-gated channel in order to produce a synaptic potential in the postsynaptic
neuron (can be inhibitory or excitatory)

Question:
3. Where are ligand-gated channels only found?

Answer:
- in the soma and dendrites

Question:
4. Explain what terminates the NT in the synaptic cleft

Answer:
- enzymes in the synaptic cleft that metabolize the NT or by endocytosis of the
NT by the presynaptic terminal

Question:
5. What are the conditions in order for a molecule to be
classified as a NT?

Answer:
1) must be released by thepresynaptic action potential
2) must have a post-synaptic receptor

,Question:
6. How are NTs classified?

Answer:
based on chemical structure

Question:
7. List the different types of NTs

Answer:
- peptides
- gases
- lipids
- purines
- AAs
- biogenic amines
- acetylcholine

Question:
8. What are the most common NTs in the CNS?

Answer:
- glutamate (excitatory)
-GABA(inhibitory)

Question:
9. Where is the NT ACh found?

Answer:
- neuromuscular jnctions

Question:
10. What does the action of a NT depend on?

Answer:
- depeds on its receptor, which may be ionotropic or metabotropic

Question:
11. Differentiate between an ionotropic and metabotropic
receptor

Answer:
1. Ionotropic: receptor is part of ion channel
2. Metabotropic: receptor is separate from ion channel and activates it through a
metabolic pathway

, Question:
12. Explain how ACh acts on receptors that produce
opposite effects

Answer:
- ACh acts on nicotinic receptros to depolarize skeletal muscle cells. This is an
excitatory effect
- ACh also acts on muscaranic receptors to hyperpolarize cardiac muscle cells

Question:
13. Explain Muscaranic receptors

Answer:
- dont have channels
- go through a metabolic pathway
- key result is the inflow of K, which hyperpolarizes
- this is an inhibitory effect

Question:
14. What do graded postsynaptic potentials result from?

Answer:
- the summation of successive synaptic potentials which can exhibit temporal
summation (ex: postsynaptic effects of one terminal activated in rapid succession)
- Also spatial summation (ex: postsynaptic effects of several terminals activated
simultaneously)

Question:
15. What happens if the ligand-gated channel of the
postsynaptic receptor is selective to the flow Na?

Answer:
- sodium will enter and depolarize or excite the postsynaptic neuron, producing
an excitatory postsynaptic potential (EPSP)

Question:
16. What happens if the ligand-gated channel of the
postsynaptic receptor is selective to the flow K?

Answer:
- potassium will leave and hyperpolarize or inhibit the postsynaptic neuron,
producing an inhibitory postsynaptic potential (IPSP)