L10: Neurobiology IV

Question 1

major cation in intracellular fluid

Answer 1

K+

Question 2

major cation in extracellular fluid

Answer 2

NA+

Question 3

major anion in intracellular fluid

Answer 3

phosphate ions and negatively charged proteins

Question 4

major anion in extracellular fluid

Answer 4

Cl-

Question 5

intracellular fluid is slightly

Answer 5

negative

Question 6

extracellular fluid is slightly

Answer 6

positive

Question 7

the two compartments exist in a state of

Answer 7

electrical disequilibrium

Question 8

to generate a membrane potential difference

Answer 8

active transporter is inserted into the membrane

Question 9

transporter ___ to move a positive ion out of the cell against it’s concentration gradient

Answer 9

uses energy

Question 10

the combination of electrical and concentration gradients

Answer 10

electrochemical gradient

Question 11

resting membrane potential

Answer 11

electrical gradient between the extra and intra cellular fluids

Question 12

the membrane potential that exactly opposes the concentration gradient of the ion is known as

Answer 12

equilibrium potential

Question 13

Nernst equation

Answer 13

Eion = 61/z * log(ion(out)/ion(in))

Question 14

the greater the membrane permeability to an ion species,

Answer 14

the greater the contribution that ion species will make to the membrane potential

Question 15

pump moves

Answer 15

3 Na+ out of the cell and 2 K+ in

Question 16

pump

Answer 16

maintains the concentration gradients down which the ions diffuse to produce the charge separation

Question 17

graded potentials generally occur

Answer 17

in the dendrites and cell bodies

Question 18

absolute refractory period occurs

Answer 18

when voltage-gated Na+ channels are open or have proceeded to the inactivated state

Question 19

what follows the absolute refractory period?

Answer 19

relative refractory period

Question 20

graded potentials

Answer 20

variable in terms of amplitude and duration and are conducted decrementally

Question 21

action potential

Answer 21

a rapid change in the membrane potential with rapid depolarization and repolarization

Question 22

action potentials starts at

Answer 22

trigger zone