NERVE PHYSIOLOGY

Question 1

coordinates the activities of the other organs in response to signals from the external and internal environment

functions as activation of muscles for movement, control of glandular secretion, regulation of heart rate and blood pressure, and maintenance of body tempt

Answer 1

nervous system

Question 2

brain and spinal cord enclosed in bony coverings

Answer 2

central nervous system

Question 3

cranial and spinal nerves

Answer 3

peripheral nervous system

Question 4

supportive cells
non excitable
regulation, support physical and and metabolic needs of neurons

Answer 4

neuroglia

Question 5

excitable cells
specialized for communication and signaling
mostly amitotic, with a high metabolic rate

Answer 5

neurons

Question 6

neuroglia in the CNS

Answer 6

microglia
ependymal cells
astrocytes
oligodendrocytes

Question 7

neuroglia in the PNS

Answer 7

satellite cells
schwann cells

Question 8

myelinating cell in the PNS

Answer 8

schwann cells

Question 9

encapsulate dorsal root and cranial nerve ganglion

Answer 9

satellite cells

Question 10

in the CNS
most abundant
controls the chemical environment
aids in synapse formation; buffer the extracellular environment
connects neurons to blood vessels

Answer 10

Astrocytes

Question 11

in the cns it is a myelinating cell

Answer 11

oligodendrocytes

Question 12

in the cns
phagocytic cell
important role in immune responses

Answer 12

microglia

Question 13

ciliated
forms the epithelium lining the ventricular spaces of the brain, contains CSF

Answer 13

ependymal cells

Question 14

functional unit
interconnected neurons
coded by action potentials

Answer 14

neurons

Question 15

axon hillock

Answer 15

area where the action potentials are created

Question 16

axon terminal

Answer 16

presynaptic terminal; where neurotransmitters are located, majority of NTAs are acetylcholine

Question 17

increases the speed of nerve impulses transmission

dendrites are unmyelinated

Answer 17

myelin sheath

Question 18

requires metabolic energy and involves calcium ions

guided by microtubules (kinesin and dynein)

Answer 18

axonal transport

Question 19

membrane bound organelles and mitochondria

rate:400mm/day

Answer 19

fast axonal transport

Question 20

substances dissolved in plasma

rate 1mm/day

transports proteins such as actin, neurofilaments and microtubules

rate limiting for the regeneration of axons

Answer 20

slow axonal transport

Question 21

transport from soma toward the axon terminals

kinesin

Answer 21

anterograde axonal transport

Question 22

transport from axon terminal to the soma

involves dynein

Answer 22

retrograde axonal transport

Question 23

when a peripheral nerve is cut the part of the nerve separated from the cell body (distal part shows a series of chemical and physical degenerative changes

axon swells, myelin sheath form bead like structures

Answer 23

wallerian degeneration

Question 24

electrical potential across the cellular membrane of nerve cells

Answer 24

membrane potential

Question 25

unequal electrolytes distribution between ECF/ICF

diffusion ions down their concentration gradients

selective permeability of plasma membrane

electrical attraction of cations and anions

Answer 25

resting membrane potential

Question 26

when gated ion channels open ions, diffuse across the membrane following their ______________

this movement of charge is an electrical current and create voltage change across the membrane

Answer 26

electrochemical gradient

Question 27

inside the membrane becomes less negative (or even reverses)

increases the probability of producing nerve impulses

Answer 27

depolarization

Question 28

membrane returns to its resting membrane potential

Answer 28

repolarization

Question 29

inside of the membrane becomes more negative than the resting potential

reduces the probability of producing nerve impulses

Answer 29

hyperpolarization

Question 30

local disturbances in membrane potential

depolarization decreases potential across cell membrane due to opening of gated Na+ channels

Na+ rushes in down concentration and electrical gradients

Answer 30

graded or local potential

Question 31

amplitude is proportional to the size of the stimulus

Answer 31

graded

Question 32

decremental
does not spread

Answer 32

short distance signals

Question 33

additive effect of several subthreshold stimuli in the regeneration of nerve impulses

Answer 33

summation

Question 34

the same presynaptic neuron stimulates the postsynaptic neuron multiple times in a brief period

Answer 34

temporal summation

Question 35

multiple neurons all stimulate postsynaptic neuron

Answer 35

spatial summation

Question 36

rapid all or none change in the membrane potential following of the nerve by a suitable threshold stimulus

voltage dependent ion channels

Answer 36

action potential

Question 37

during the time when Na+ activation channels are open and inactivation channels are closed, the membrane cannot respond to another stimulus

(Na+ channels must be in their resting state to respond to another stimulus)

Answer 37

Absolute refractory period

Question 38

for a time after the absolute refractory period (when Na+ channels are in their resting state) the K+ channels are still open

during this time the threshold to start another action potential is increased

Answer 38

Relative refractory period

Question 39

depolarization only at nodes of ranvier (areas along the axon that are unmyelinated and where there is high density of voltage-gated ion channels)

current carried by ions flows through extracellular fluid from node to node

Answer 39

saltatory conduction

Question 40

an action potential spreads (propagates) over the surface of the axolemma

an action potential must pass through each point along the neuron cell membrane which makes the conduction of the nerve impulse relatively slow

Answer 40

continuous conduction