1. Neurophysio Part 1 : electrical props and AP

Question 1

_____ are made in the cell and located intracellularly. They produce a more neg charge in the cell

Answer 1

protein

Question 2

There is ______ NRG created from the chem conc gradient

Answer 2

potential nrg

Question 3

________: the membrane potential when there is a balance btw electrical and chem forces

Answer 3

equilibrium potential

Question 4

What are two effects that equilibrium potential is dependent on

Answer 4

1. intra/extrcellular ionic concentration

2. electrical charge of ion

Question 5

equilibrium potential predicts (2)

Answer 5

1. direction of ionic flow

2. DRIVING FORCE

Question 6

the loss of K+ results in a ____ charge on the inner plasma membrane face

Answer 6

negative charge

Question 7

______: when there is only 1 ion affecting membrane potential

Answer 7

reversal potential

Question 8

Equil potential for K+ is ______mV

Answer 8

-87mV

Question 9

** most of the cells RMP is determined by the equil potential for ____

Answer 9

K+

Bc of the leaky K+ channels

Question 10

RMP values for most cells range from ___ to ___mV

Answer 10

-65mV to -95mV

Question 11

RMP is related to the conc. of what three ions

Answer 11

Na+, K+, and Cl-

Question 12

According to GHK, RMP is related to what 2 factors?

Answer 12

conc gradient of ions (Na+, K+, Cl-)

cells permeability to each

Question 13

at RMP the cell is ___x more permeable for K than other ions

Answer 13

1000s

Question 14

What are the two major forces acting on the movement of ions across the cell membrane

Answer 14

• charge

- conc gradient

Question 15

____ equation is used to determine the value of membrane potential when there is NO NET DIFFUSIOn of any 1 given ion

Answer 15

nernst equation

• will give the electrical potential NRG for 1 ion

Question 16

____ equation is used to determine the RMP when there is NO NET DIFFUSION of ALL ions across the cell membrane

Answer 16

GHK

• gives the reversal potential

Question 17

_____: the ionic flow that will occur once the channel opens

Answer 17

driving force

Question 18

_____= RMP-equil. Potential

Answer 18

driving force

Question 19

the larger the _____ , the faster the ionic current will travel

Answer 19

driving force

Question 20

What are three channel types

Answer 20

leaky ions
ligand
voltage

Question 21

** The _____ gated channel signal the ____ gated channel

Answer 21

ligand signal the voltage gated

Question 22

Changes in membrane potential affect the props of _____

Answer 22

voltage gated

Question 23

when the membrane potential moves ____mV toward positive the voltage gated channel will open

Answer 23

20mV

Question 24

____ gated channels have an all or non mechanism

Answer 24

voltage gated

Question 25

_______: the current flow of voltage gated channels depolarize and further AP regeneration along the neuronal axon , repeats until it reaches the terminal

Answer 25

positive feedback loop

Question 26

Na+ channels use 2 mech to allow ionic flow across the membrane

Answer 26

1. ligand gated channels (AcH) | 2. voltage gated channels

Question 27

What is the neurotransmitter that is used to stim the ligand gated channel of Na+

Answer 27

AcH

Question 28

EPSP is due to ___ ions

Answer 28

Na+

Question 29

IPSP is due to ___ ions

Answer 29

Cl-

Question 30

______ ions cause hyperpolarization. | ______ions cause depolarization

Answer 30

``` Cl- = hyperpolar Na+ = depolar ```

Question 31

How is a graded potential turned into an AP

Answer 31

summation - leakage in the membrane prevents EPSP from going straight into an AP

Question 32

The EPSP has to be summed to threshold at ___ to ___ mV above resting potential for a spike to occur= AP

Answer 32

15 to 20mV

Question 33

_____ : where the axon and the stoma meet. Has Na+ channels that can illiciate AP

Answer 33

axon hillock

Question 34

Voltage gated Na+ channels inactivated via _____ mechanism

Answer 34

ball and chain | - keeps the AP moving in one direction

Question 35

___ voltage gated channels only open after the cell has depolarized so much that the membrane is close to +30mV

Answer 35

K+ (overshoots) - at this pt there is a driving force for K+ to move out so that it can go back to its equil of -90mV (repolarize)

Question 36

K+ equilibrium potential is ____ mV. When this membrane potential is reached the cell is said to be in ____

Answer 36

-90mV = Repolarization

Question 37

Na+/K+ ATPase pump begins working when it senses an increase in intracellular ____ conc

Answer 37

Na+

Question 38

____period: voltage gated Na+ channels woll not open, regardless of stim strength

Answer 38

absolute refractory period

Question 39

_____period: the voltage gated K+ channels have opened, the driving force for K+ to leave the cell is stronger than the driving force for Na+ to enter

Answer 39

relative refractory period - must have a very high Na+ stim for an AP to be acheiveable

Question 40

____: the degree to which ion channels are open for a given area on the cell membrane

Answer 40

conductance

Question 41

Conductance is the inverse of _____

Answer 41

resistance

Question 42

Ohm law equation

Answer 42

V= I x R velocity = current X resistance

Question 43

greater resistance in the membrane than in the cytoplasm, the current will tens to flow through the ____rather than leak back out into the ___

Answer 43

flow through the cytoplasm instead of back out into membrane (path of least resistance)

Question 44

the fatter the axon, the ______ it has for ions to flow in

Answer 44

more area

Question 45

______ causes axons to conduct AP faster

Answer 45

myeline

Question 46

______: myelinates axons conduct AP faster than unmyelinates axons

Answer 46

saltatory conduction

Question 47

____ channels are used in vesicle binding and release of neurotransmitter

Answer 47

voltage gated Ca+2

Question 48

voltage gates Ca+2 channels are used in ___ binding and release of ____

Answer 48

vesicle binding and release of NT

Question 49

____ & ___ are docking proteins that tie vesicles to active zones

Answer 49

actin & synaptophysin

Question 50

Ca+2 causes ____ to contract, and bring vesicles forward to the membrane

Answer 50

actin

Question 51

2 actions that occur when there is a Ca+2 influx

Answer 51

1. causes actin to contract - brings vesicles forward | 2. activates Calmodulin, causes release of vesicle content into the cleft

Question 52

When Ca+2 binds to ____ , vesicle content is released into the cleft

Answer 52

calmodulin

Question 53

____ helps to withdraw vesicle components back into the synaptic cleft after Ca_2 binds to calmodulin

Answer 53

clathrin

Question 54

A ___ amt of NT is released for ea. AP

Answer 54

fixed