lecture 4: neurons and membrane potential

Question 1

astrocytes

Answer 1

support cells, control extracellular environment of neurons

Question 2

microglia

Answer 2

“immune system” of the CNS

Question 3

ependymal cells

Answer 3

ciliated involved with production of CSF and CSF movment

Question 4

oligodendrocytes

Answer 4

responsible for myelinatino

Question 5

sensory neurons

Answer 5

afferent neurons of PNS (go to brain)

Question 6

motor neurons

Answer 6

efferent (away from brain)

Question 7

What does SAME stand for

Answer 7

sensory afferent, motor efferent

Question 8

interneurons

Answer 8

communication within CNS and between sensory/motor

Question 9

neural plasticirty

Answer 9

early in development, the brain has much greater potential for remodeling in response to stimulation or injury than in the adult brain

Question 10

what is the resting membrane potential

Answer 10

-70 mV

Question 11

depolarization is movement closer to

Answer 11

0 mV

Question 12

membrane potential exists because of

Answer 12

concentration gradients intracellular-extracellular
selective permeability of membrane
sodium-potassium ATPase

Question 13

selective permeability of leak channels, along with the action of the sodium-potassium ATPase, lead to the development of

Answer 13

membrane potential

Question 14

graded potential

Answer 14

• change in membrane potential affecting a local area
• signal decreases as distance from stimulus increases

Question 15

when the cell is repolarizing, Na+ channels are in the __ state

Answer 15

inactivated

Question 16

which two channels often serve as the initial stimulus for an action potential

Answer 16

ligand-gated and mechanically gated

Question 17

voltage-gated Na+ channels __ the cell

Answer 17

depolarize

Question 18

voltage-gated K+ channels __ the cell

Answer 18

repolarize

Question 19

absolute refractory period

Answer 19

cell is incapable of depolarizing

Question 20

relative refractory period

Answer 20

cell can depolarize if supplied with a stronger-than-usual stimulus

Question 21

action potential propagation

Answer 21

build of action potentials
* the velocity with which an action potential propagates along a membrane depends upon fiber diameter and whether or not the fiber is myelinated

Question 22

what is the most optimal fiber for an AP to travel down

Answer 22

larger diameter, myelinated

Question 23

saltatory conduction

Answer 23

when an AP jumps from node to node