electrical signals

Question 0

why does the body use electrical signals?

Answer 0

to transfer information from one part of the body to another

Question 1

what are electrical signals of the cells called?

Answer 1

AP

Question 2

what is an AP

Answer 2

an electrical signal produced by cells

Question 3

what does the body use to transfer information from one part to another?

Answer 3

electrical signals/APs

Question 4

what creates the electric properties of the cell membrane?

Answer 4

ionic concentration differences across the plasma membrane and its permeability to those ions

Question 5

what does the Na+/K+ pump do?

Answer 5

stockpiles Na+ outside and K+ inside the plasma membrane

Question 6

why do (-) cell proteins contribute to the membrane potential?

Answer 6

they are too big to exit the cell

Question 7

what does the Na+/K+ pump require to funciton?

Answer 7

ATP–it is an active transport pump

Question 8

at the immediate outside and inside of the cell membrane

Answer 8

ions concentrate to create a voltage difference

Question 9

the overall charge difference between intercellular and extracellular?

Answer 9

there is none, voltage difference is only directly inside and outside the cell membrane

Question 10

what creates the charge differential between the inside and outside of the membrane

Answer 10

the concentration difference of ions just across the membranes

Question 11

what is the average membrane potential measurement?

Answer 11

-85 mV

Question 12

what membrane protein helps to set up ion differences?

Answer 12

Na+/K+ pump

Question 13

non-gated K+ channel proteins are leaky to K+, why?

Answer 13

they are not gated so they are just open and the concentration gradient is such that the K+ wants to go outside the cell from an area of higher to lower concentration

Question 14

what type of membrane protein allows K+ to dribble out of the cell with the concentration gradient?

Answer 14

non-gated K+ channel protein

Question 15

when the K+ diffuses out through the non-gated channel proteins, this gives the cell a ____ charge just outside the membrane and ___________ still inside the cell create a ___ charge just inside the membrane

Answer 15

positive
large negative proteins
negative

Question 16

what would happen if v-gated K+ channels were to open?

Answer 16

much more K+ would diffuse out of the cell due to concentration gradient and the charge difference would increase and the membrane would be hyperpoerized

Question 17

what would happen if v-gated Na+ channels were opened?

Answer 17

Na+ would diffuse into the cell bc of the concentration gradient and this would serve to depolarize the cell (making the inside more + when it is usually -)

Question 18

how would an extracellular increase in K+ change the RMP?

Answer 18

a build-up of K+ on the outside of the cell would slow the release of K+ from inside the cell and would cause the interior of the cell to move more toward positive charge. The charge difference between the immediate inside and outside of the cell membrane is smaller, thus it is depolarized

Question 19

define depolarization of the membrane

Answer 19

the membrane potential becomes more (+), it moves towards 0

Question 20

when the membrane potential becomes more negative (the difference moves further away from negative) this is called

Answer 20

hyperpolarization

Question 21

is the concentration of K+ higher inside or outside the cell?

Answer 21

inside

Question 22

is the concentration of Na+ higher inside or outside the cell?

Answer 22

outside

Question 23

to which ion is the plasma membrane most permeable to?

Answer 23

K+

Question 24

what anions are trapped inside the cell?

Answer 24

negatively charged large proteins

Question 25

gated ion channels change the _________ of the cell membrane

Answer 25

permeability

Question 26

gated ion channels open and close because of some sort of

Answer 26

stimulus

Question 27

ligand gated ion channels open or lose in response to

Answer 27

ligand binding to receptor protein

Question 28

what are usually the receptor proteins on a ligand gated ion channel?

Answer 28

glycoproteins

Question 29

voltage gated ion channels open or close in response to small voltage changes where?

Answer 29

across the cell membrane

Question 30

most common voltage gated ion channels are

Answer 30

Na+ and K+ | Ca++ important on cardiac and smooth muscle

Question 31

what do touch receptors respond to?

Answer 31

mechanical stim of the skin

Question 32

temperature changes in the skin trigger what kind of gated ion channel?

Answer 32

temperature receptor gated ion channel

Question 33

the relative charge of an area of membrane changes and opens

Answer 33

voltage-gated ion channels

Question 34

local potentials can be stimulated by

Answer 34

``` ligands binding to receptors (ligand gated) relative change in charge (v-gated) mechanical stimulation (touch) temperature changes (T receptors) spontaneous change in permeability ```

Question 35

local potentials are called ________ potentials because the magnitude varies

Answer 35

graded

Question 36

what are things that can have an effect the grade of a local potential?

Answer 36

stimulus strength | stimulus frequency

Question 37

local potentials can add onto each other in a process called

Answer 37

summation

Question 38

stimulus strength or frequency can vary the _______ of a graded local potential

Answer 38

magnitude

Question 39

local potentials rapidly (decrease/increase) in magnitude as they spread over the surface of the plasma membrane

Answer 39

decrease

Question 40

what do local potentials do when they summate?

Answer 40

add onto each other

Question 41

can local potentials cause generation of an AP?

Answer 41

yes

Question 42

local potentials are caused when a stimulus causes ______

Answer 42

ion channels to open

Question 43

increased local permeability is caused by

Answer 43

opening of the ion channels by a local potential caused by a stimulus

Question 44

increased permeability to Na+ results in

Answer 44

depolarization of the plasma membrane

Question 45

increased permeability to K+ (or Cl-) has what effect on the plasma membrane?

Answer 45

hyperpolarizes

Question 46

depolarization can be caused by increased permeability in the plasma membrane to what ion?

Answer 46

Na+

Question 47

hyperpolarization can be caused by increased permeability in the plasma membrane with what ion?

Answer 47

K+ or cl-

Question 48

what does it mean to say that local potentials are graded?

Answer 48

the size of the response is proportional to the strength of the stimulus

Question 49

why is a local potential produced in response to several stimuli larger than one produced in response to one stimulus?

Answer 49

the local potentials summate, meaning they add together

Question 50

local potentials spread and decrease in magnitude in a manor called

Answer 50

decremental

Question 51

an AP can be caused by a depolarizing

Answer 51

local potential that is large enough

Question 52

a large enough local potential may cause the membrane to reach

Answer 52

threshold

Question 53

what must a stimulus or local potential reach in order to trigger an AP

Answer 53

threshold

Question 54

what does the all-or-none principle for AP mean

Answer 54

no matter how strong a stimulus, as long as it reaches threshold, an AP will occur

Question 55

what are the phases of an AP

Answer 55

depolarization (more positive) | repolarization (less positive)

Question 56

what is the afterpotential?

Answer 56

a slight hyperpolarization "dip" after repolarization

Question 57

depolarization is the result of

Answer 57

increased membrane permeability to Na+ and mvmt of Na+ into the cell (activation of the v-gated Na+ channels)

Question 58

repolarization is the result of

Answer 58

decreased membrane permeability to K+ this stops the entrance of Na+ into the cell (v-gated Na+ gates close) more K+ move out of the cell (v-gated K+ gates close)

Question 59

what is produced during the absolute refractory period of the AP

Answer 59

nothing

Question 60

what can be produced during the relative refractory period

Answer 60

an AP if a stronger than threshold stimulus

Question 61

AP is propogated and for a given axon the magnitude of the AP is

Answer 61

constant

Question 62

stimulus strength determines the

Answer 62

frequency of the AP