Resting Membrane Physiology

Question 1

the difference in concentration of a charged
particle between one point and another.

Answer 1

electrical potential (EP)

Question 2

charged particles flow from
one place to another through ion channels or membranes.

Answer 2

Current flow

Question 3

In other cells like
glands, macrophages and ciliated cells local changes in membrane
potential (MP) to

Answer 3

activate many of the cell functions.

Question 4

In nerve and
muscle cells rapidly changing electrochemical impulses which are used to

Answer 4

transmit signals

Question 5

Production of graded potential and action potential depends on :

Answer 5

1. Presence of specific ion channels
2. Resting membrane potential

Question 6

Selectivity is based on

Answer 6

1. The charge lining the channel
2. Size of the channel

Question 7

Channels that are always open :

Answer 7

Leaky channels

Question 8

Gates controlled by changes in membrane potential

Answer 8

.Voltage-gated:

Question 9

Acetylcholine binds to nicotinic receptor is an example of which type of gated channel ?

Answer 9

Ligand gated

Question 10

What are the two types of ligand channels ?

Answer 10

Sensors located extracellularly
Sensors located intracellularly

Question 11

Pacinian corpuscle in skin is an example of which channel ?

Answer 11

Mechanical

Question 12

T/F: A diffusion potential is the potential
difference generated across a membrane
when a charged ion diffuses against its
concentration gradient.

Answer 12

False down

Question 13

Which of the following would INHIBIT diffusion potential from being generated ?
A)large conc. gradient
B) low conc. gradient
C)permeable membrane
D)impermeable membrane

Answer 13

D

Question 14

The magnitude (amount) of a diffusion
potential is measured in

Answer 14

millivolts (mV)

Question 15

The magnitude (amount) of a diffusion
potential depends on

Answer 15

size of concentration gradient

Question 16

The sign of diffusion potential depends on

Answer 16

the charge of diffusing ion

Question 17

when diffusion slows and then
stops; and there is no net movement of that ion; a stage called

Answer 17

Equilibrium
potential

Question 18

is the Diffusion potential that exactly balances
or opposes the tendency for diffusion down the concentration difference.

Answer 18

Equilibrium potential

Question 19

Current flow depends

Answer 19

Net force ( conc. and electrical)
Membrane permeability

Question 20

What ion has opposing forces and what are its opposing forces ?

Answer 20

Potassium
Electrical gradient attracts it inside
Conc. gradient attracts it outside

Question 21

What is the equilibrium potential of potassium ?

Answer 21

-94 millivolts with negativity inside and positivity outside.

Question 22

What ion has 2 forces working together to move it ? What are they

Answer 22

Sodium
Electrical and conc. gradients both move sodium into the cell

Question 23

What is the equilibrium potential of sodium ?

Answer 23

Equilibrium potential for Na+ is +61 mv with
positivity inside and negativity outside

Question 24

Equilibrium potential for cl-

Answer 24

-65 (-63)

Question 25

to calculate the equilibrium potential for an ion at a given concentration difference across a membrane, assuming that membrane is permeable to that ion. The equilibrium potential is calculated for one ion at a time.

Answer 25

The Nernst equation

Question 26

————————the convert of concentration difference of an ion into a voltage at a given temperature, gas and faraday constant

Answer 26

Nernst potential for that ion.

Question 27

Nernst potential magnitude depends on

Answer 27

Proportionally with the ratio of concentrations of that specific ion on two sides of the membrane

Question 28

Formula of nernst

Answer 28

E (millivolts) = ± 61x log concentration inside/ concentration outside

Question 29

equation is used to determine the resting membrane potential (RMP) in the cell with involvement of Na, K and Cl ions; the 3 most important ions responsible for developing membrane potential

Answer 29

Goldman-Hodgkin-Katz equation

Question 30

When a membrane is permeable to several different ions, then resulting diffusion potential depends on 3 factors:

Answer 30

1.Electrical charge of each ion 2. Permeability of membrane to that specific ion 3. Concentration of ions inside and outside the membrane

Question 31

resting membrane potential (RMP) in the cell with involvement of Na, K and Cl ions equals to

Answer 31

-86 mV

Question 32

when membrane is not responding to any stimulus is called

Answer 32

resting membrane potential [RMP].

Question 33

What type of potential establishes RMP

Answer 33

Diffusion potential

Question 34

What is the RMP in a large nerve ?

Answer 34

-90mV

Question 35

The EP of highly permeable ions is closer to the value of the RMP due to their high permeability ?

Answer 35

Yes ie potassium

Question 36

What channels are important for resting membrane potential ?

Answer 36

K leaky channels and Na K pump

Question 37

T/F: Having a membrane potential does not make membrane excitable

Answer 37

True

Question 38

Excitability depends upon

Answer 38

the possibility of depolarization or reversal of polarised potential

Question 39

——————- open in response to a stimulus and allow particular ions to pass through and to change the polarized state to depolarized state. A) leaky channels B)gated channels C) EP D) current flow

Answer 39

B

Question 40

GP channels :

Answer 40

ligand gated or mechanically gated ion channel

Question 41

GP are produced at

Answer 41

dendrites and soma of neuron

Question 42

Hyper polarisation signals cause what kind of graded potential?

Answer 42

IPSP

Question 43

Depolarisation graded potential causes what kind if signal

Answer 43

EPSP

Question 44

the part of neuron from where axon arises

Answer 44

Axon hillock

Question 45

is the part of axon hillock where action potential is produced.

Answer 45

Initial segment

Question 46

chemical and electrical forces acting on that ion are equal and no further net diffusion of that ion occurs

Answer 46

electrochemical equilibrium,

Question 47

RMP in a large nerve with the na pump contribution =

Answer 47

-90

Question 48

Area in nerve rich in voltage gated Na+ channels

Answer 48

Trigger zone in initial segment