Transmission 2 Resting Membrane Potentials

Question 1

Why do we call it a membrane potential?

Answer 1

because inside of cell has a different change then outside the cell

Question 2

what is the usual internal cell voltage at rest?

Answer 2

-70MV

Question 3

Membrane permeability is _______ for NA+ ad K+ ions.

Answer 3

diffrent

Question 4

there are ______ ___leak channels than ___ leak Channels

Answer 4

more K+, Na+

Question 5

K+ ions ______ _____ as Na+ ____ ___ .

Answer 5

leak out, leak in

Question 6

what maintains resting membrane potential?

Answer 6

Na+ -K+ Pump

Question 7

An alteration in the potential surrounding a membrane causes a neuron to produce a ______ ______ or triggers _____ ______ to contract

Answer 7

nerve impulse

muscle fibers

Question 8

what 2 things are referred to as excitable cells

Answer 8

neurons and muscle fibers

Question 9

when an excitable cell is inactive it is at its?

Answer 9

resting potential

Question 10

changes in membrane potential result in either a _____ _____ or an _____ ______

Answer 10

graded potential

action potential

Question 11

what is a graded potential?

Answer 11

impulses that excite or inhibit further action

Question 12

what is an action potential?

in a nerve fiber it stimulates a ____ _____ and in a muscle fiber it stimulates _______

Answer 12

some kind of response
nerve impluse
contraction

Question 13

what are ion channels?

Answer 13

tube-shaped protien channels across the memebrane

Question 14

what do ion channels do?

Answer 14

allow specific ions to move across the membrane

Question 15

the direction of ion flow through a channel depends on the _______ in concentration of ____ _____ action on the ion.

Answer 15

difference

electrical charge action

Question 16

ions passively defuse through a Chanel from ______ to _____ concentration. they are also attracted by _____ _____. or repelled by ______ charges

Answer 16

high to low
opposite charges
like

Question 17

the direction of ion flow depends on _____ and _____ forces acting on the ion at any given time.

Answer 17

chemical and electrical

Question 18

there are ___ types of channels of which ions can pass

Answer 18

4

Question 19

keak channels contribute greatly to matinice of ____ ____ potential

Answer 19

resting membrane

Question 20

a chemically gated channel has a _____ associated with it.. wha

Answer 20

receptor

Question 21

when a chemically gated channel is occupied by a neaurotransmitter the gate of the channel _____ allowing a _____ type of ion to diffuse through. the gate will remain open as long as the ____ is ____

Answer 21

opens.
specific
receptor is occupied

Question 22

a voltage-gated channel opens at a specific voltage known as the ______.

Answer 22

threshhold

Question 23

the threshold for a voltage-gated sodium channel is around.

Answer 23

-55mv

Question 24

when the membrane increases from its resting potential of ___ to the _____ the Chanel gate opens and sodium diffuses through the channel to the other side of the membrane.

Answer 24

-70mv

threshold

Question 25

channels open at varying speeds despite reaching ____ at the same time

Answer 25

threshold

Question 26

some voltage-gated channels have an additional gate known as?

Answer 26

inactivation gate

Question 27

inactivation gates ______ _____ the channel so ions _____ pass trough even if their activation gate is open

Answer 27

temporarily plug

cannot

Question 28

inactivation gate propose is so that ions ___ ____ pass through the gate at an _____ time

Answer 28

do not

appropriate

Question 29

mechanically gated chenels are found in?
found primarily in the ______ to inform the NS of _____ changes in the surface of the body resulting from conditions in the envirmoment

Answer 29

sensory receptors
skin
mechanical

Question 30

mechanically gated channels open when _______, _______ or _____ is applied to the membrane

Answer 30

pressure, touch or stretch

Question 31

an ion pump is a type of membrane _____ protein

Answer 31

transport

Question 32

an ion pump requires ____ to push ions form areas of ______ concentration to areas of _____concentration.

Answer 32

energy

lower, higher

Question 33

what pump is most important in maintenance of membrane potnetial?

Answer 33

Sodium potassium pump

Question 34

the Sodium potassium pump uses what as energy?

Answer 34

ATP

Question 35

Sodium potassium pump pumps _____ sodium ions out of the cell and ___ potassium ions into the cell AT THE SAME TIME.

Answer 35

3

2

Question 36

leak channels and ion pumps complement each other to maintain a constant ______ _______ and level of ion

Answer 36

electrical potential

concentration

Question 37

the resting membrane potential voltage is determined by the concentration of _____ charged ions on either side of the membrane. established primarily by?

Answer 37

electrically charged

leak channels

Question 38

there are more _____ leak channels then _____

Answer 38

Potassium

sodium

Question 39

the Na+ -K+ pump moves more ____ then ____ in

Answer 39

NA

PA

Question 40

because the resting membrane is negative on the inside and positive on the outside it is considered to be ______

Answer 40

polarised

Question 41

the voltage created by this resting distribution of ions is known as the

Answer 41

membrane potential