Nerve physiology

Question 1

Unidirectional transmission of impulse

Answer 1

ORTHODROMIC TRANSMISSION

Question 2

Stimulation of an axon will transmit impulse away from the cell body

Answer 2

Anterograde

Question 3

Stimulation of a dendrite will transmit impulse towards the cell body

Answer 3

Retrograd

Question 4

ANTIDROMIC TRANSMISSION

Answer 4

Stimulation of the central portion of the axon will result a bidirectional transmission of impulses; towards the cell body and away from the cell body

Question 5

13. Which type of nerve fibers innervate the polymodal nociceptors?
A. Aα
B. Aβ
C. Aδ
D. C fibers

Answer 5

D

Question 6

14. Stimulation of which of the following fibers give rise to a longer-lasting, burning and pricking pain?
A. Aα
B. Aβ
C. Aδ
D. C fibers

Answer 6

D

Question 7

17. Which of the following mechanisms explain why visceral pain tends to be vague and poorly localized than (somatic?) pain?
    A. There are more C fibers in visceral afferents than Aδ.
    B. There is less overlapping of receptive fields in the viscera.
    C. There are more visceral afferents that cover a wide area.
    D. Visceral afferents demonstrate more converging synaptic pattern than somatic afferents

Answer 7

A

Question 8

102. the ff are characteristics of the C fibers except
     a. small myelinated
     b. conduction velocity ranges from .5 to 2 m/sec
     c. conducts dull burning poorly localized pain
     d. conducts temperature
     e. no exception

Answer 8

A

Question 9

104. Vibration and position sense is conducted by ______ nerve fibers
     a. a-alpha
     b. a-beta
     c. a-gamma
     d. a-delta
     e. a and b

Answer 9

E

Question 10

103. the following is true of the myelin sheath
     a. it is deposited around the axon by Schwann cells
     b. it is an excellent insulator for the nerve
     c. it facilitates salutatory conduction
     d. it increases the velocity of the nerve transmission
     e. all of the above

Answer 10

E

Question 11

Myelin production in

____ for Peripheral nervous system (SR)

___ for Central nerve system (OC

Answer 11

Schwann Cells

oligodendrocytes

Question 12

An action potential arriving at the presynaptic terminal causes…
A) voltage-gated sodium ion channels to open, and sodium ions to diffuse into the cell.
B) voltage-gated sodium ion channels to open, and sodium ions to diffuse out of the cell.
C) voltage-gated calcium ion channels to open, and calcium ions to diffuse into the cell.
D) acetylcholine to diffuse into the cell.
E) ligand-gated sodium channels to open, and sodium ions to diffuse out of the cell.

Answer 12

C

Question 13

As a result of question number one…
A) synaptic vessels migrate to the plasma membrane and release acetylcholine.
B) acetylcholine is actively transported from the pre-synaptic neuron.
C) acetylcholine is actively transported to the post synaptic neuron.
D) ligand-gated sodium channels open.
E) sodium ions diffuse into the cell.

Answer 13

A

Question 14

Acetylcholine has which effect on the post-synaptic neuron?
A) Ligand gated calcium ion channels open and calcium diffuses in.
B) Ligand gated sodium ion channels open and sodium diffuses in.
C) Terminal vessels migrate to the plasma membrane.
D) Voltage gated calcium ion channels open and calcium diffuses in.
E) Voltage gated sodium ion channels open and sodium diffuses in.

Answer 14

B

Question 15

If the post-synaptic membrane potential reaches threshold level, an action potential will be produced.
A) True
B) False

Answer 15

A

Question 16

Acetylcholine is actively transported from the pre-synaptic membrane to the post-synaptic membrane.
A) True
B) False

Answer 16

B

Question 17

—: membrane protein attached on the membrane of the vesicle
Vesicle associated membrane protein
—- :
attached to the membrane of the presynaptic cell

– and –:
enhance binding of the synaptobrevin and syntaxin

Answer 17

Synaptobrevin

Syntaxin

SNAP 25 and Rab 3

Question 18

moa of botulinum infection?

Answer 18

destroy snare proteins; exocytosis of NTs cannot occur

Question 19

Graded potentials:

__:
Depolarizes membrane potential
___:
Hyperpolarizes membrane potential

Answer 19

Excitatory (produces EPSP)

Inhibitory (produces IPSP)

Question 20

—-are changes in membranepotentialthat vary in size, as opposed to being all-or-none.

They arise from the summation of the individual actions of ligand-gated ion channel proteins, and decrease over time and space. They do not typically involve voltage-gated sodium and potassium channels.

Answer 20

Graded potentials

Question 21

Most often evoked by GABA or glycine-ergic presynaptic neurons

Neurotransmitter binding opens Cl- channels

Answer 21

IPSP

Question 22

Most often evoked by glutaminergic (CNS) and cholinergic (PNS) presynaptic neurons

Neurotransmitter binding opens cation channels (permeable to Na+, Ca2+, K+)

Answer 22

EPSP

Question 23

Most often evoked by glutaminergic (CNS) and cholinergic (PNS) presynaptic neurons
Neurotransmitter binding opens cation channels (permeable to Na+, Ca2+, K+)

Answer 23

D.

Summation does not occur in action potentials because action potentials have constant amplitude and form and it is an all-or-none response

Question 24

T/F: GABA as a neurotransmitter is both excitatory and inhibitory

Answer 24

F, it is strictly inhibitory

Question 25

summation of simultaneous inputs at different sites

Answer 25

Spatial Summation

Question 26

summation of consecutive inputs at same site

Answer 26

Temporal Summation

Question 27

Which of the following is/are features of voltage-gated sodium channel/s? They are open when the membrane is hyperpolarized They have high conductance in the resting state They are closed when the cell is at rest They pump 3 sodium out of the cell and 2 potassium ions inwards

Answer 27

C

Question 28

The final physiologic action of a neurotransmitter is determined by the ____________ mechanism of termination of the physiologic effects of the neurotransmitter. intrinsic properties of the receptor that binds with the transmitter. intracellular 2nd messenger cascade system chemical properties of the neurotransmitter.

Answer 28

B

Question 29

What is the most important physiologic advantage of a chemical synapse have over an electrical synapse? Chemical synapse can amplify signal and ensure efficient signal transmission. It ensures unidirectional transmission of the action potential. It has a longer lasting effect in the nervous system It can mediate both excitatory and inhibitory responses.

Answer 29

A The simplicity of electrical synapses results in synapses that are fast, but can only produce simple behaviors compared to the more complex chemical synapses.[2]

Question 30

In another experimental set-up consisting of several interconnecting neurons, one neuronal circuit was found to be hyperexcitable. Electrical stimulation of the neuron that belonged to this circuit showed short latency and produced prolonged depolarization. If you want to diminish or inhibit the excitability of this neuronal circuit, what type of chemical substance or drug will you apply to the system? one that inhibits the voltage-gated calcium channels one that blocks sodium channels one that increases the potassium conductance Any of the above

Answer 30

D