Action Potentials- Under Construction

Question 1

Synapse

Answer 1

The site of transmission from the pre-synaptic neuron to post-synaptic neuron. Can be electrical or chemical.

Question 2

Presynaptic Neurons

Answer 2

The neuron before the synapse/synaptic cleft

Question 3

Dendrites

Answer 3

Small projects from the cell body of a neuron that receive incoming signals from other neurons and relay them to the cell body.

Question 4

Postsynaptic Neurons

Answer 4

The neuron after the snapse/synaptic cleft

Question 5

Soma (Cell Body)

Answer 5

The part of the neuron that contains the nucleus and is the site of metabolic activity. Most NTs are synthesized here.

NT = neurotransmitter

Question 6

Axon Hillock

Answer 6

Part of the cell body of a neuron that connects to the axon.

Question 7

Muscurinic receptors

Answer 7

ACh G protien coupled receptprs broadly expressed in the CNS

Question 8

Nicotinic receptors

Answer 8

ACh receptor found in the CNS and at neuromuscular junctions (open channels allowing flux of Na+, CA2+, and K+)

Question 9

Temporal summation

Answer 9

a single presynaptic neuron rapid-fires singals to a postsynaptic neuron

Question 10

Spatial summation

Answer 10

Signals come from multiple presynaptic neurons

Question 11

Resting membrane potential of large neruon

Answer 11

-90

Question 12

Voltage at which action potential occurs

Answer 12

-55

Question 13

Potassiums “buddy” in the cell

Answer 13

phosphate

Question 14

During depolarization in what configuration are the Na+ channel gates

Answer 14

Activation gate - open
Inactivation gate - open

Question 15

During repolarization in what configuration are the Na+ channel gates

Answer 15

Activation gate - open
Inactivation gate - closed

Question 16

During rest in what configuration are the
Na+ channel gates

Answer 16

Activation gate - closed
Inactivation gate - open

Question 17

during rest and depolarization in what configuration is the
K+ channel gate

Answer 17

closed

Question 18

during repolarization in what configuration is the
K+ channel gate

Answer 18

open

Question 19

What causes Vescicles to attach and exocitose neurotransmitters

Answer 19

Calcium

Question 20

Nernst potential for Cl-

Answer 20

-90mV

Question 21

Nernst potential for K+

Answer 21

-94mV

Question 22

Nernst potential for Na+

Answer 22

+61mV

Question 23

K+ efflux is how many times greater than Na+ influx

Answer 23

20 to 100 x

Question 24

Goldman Hodgkin Katz

Answer 24

concentration gratient and membrane permeability of Na+, K+, and Cl-

Question 25

Nernst Potential

Answer 25

the potential level across a membrane that will exactly prevent net diffusion of an ion in either direction

Question 26

According to the Goldman Hodgkin Katz equation sodium brings the membran potential value to what value

Answer 26

-86mV (leak channels)

Question 27

Na+K+ATPase pump creates additional electonegativity of how much

Answer 27

-4mV

Question 28

Membrane potential can change based on what

Answer 28

the size, location, and type of nerve fiber

Question 29

the Na+K+ATPase pump pushes Na+ against

Answer 29

its concentration gradient and electrical gradient

Question 30

the Na+K+ATPase pump pushes K+ against

Answer 30

its concentration gradient

Question 31

the Na+K+ATPase pump exchanges:

Answer 31

3 Na+ out and 2 K+in

Question 32

Potential energy

Answer 32

can change the state of other objects around it

Question 33

Intracellular Cations

Answer 33

K+ and Mg++

Question 34

Intracellular Anions

Answer 34

Phosphate, Protein

Question 35

Extracellular Cations

Answer 35

Na+ and Ca++

Question 36

Extracellular Anions

Answer 36

Cl- and HCO3-

Question 37

Diffusion potential

Answer 37

The difference between the concnetration inside (Ci) and the concentration outside (Co)

Question 38

What is a volt?

Answer 38

determines how fast the electrons will travel through a circuit

Question 39

Cell membrane as a capacitor

Answer 39

charges are equal within membrane everywhere except lined up along the inside (-) and outside (+) of cell membrane (this can be switched through the movement of + and - ions)

Question 40

Period during which another action potential cannot happen

Answer 40

absolute refractory period

Question 41

Period during which antoher action potentil would be difficult but not impossible to stimulate

Answer 41

relative refractory period

Question 42

Triad of resons for ionic movment once an AP has been initiated

Answer 42

1: Voltage gated channels 2: leak channels 3: Na+K+ATPase pump

Question 43

At threshold, the activation gate opens: Na+ rushes in, as permeability is increased:

Answer 43

500 to 5000 times

Question 44

When does the Na+ inactivation gate reopen after an action potential

Answer 44

once the resting membrane potential has been reached again

Question 45

Why does decreased Ca++ lead to ectopy

Answer 45

Ca+ is thought to bind to Na+ channel proteins increasing the voltage required to open the channels and invoke APs. Without Ca+ binding exitability happens easily

Question 46

2 tests to diagnose hypocalcemia

Answer 46

Chvostek's sign Trousseau's Sign

Question 47

EMF

Answer 47

Electromotive force

Question 48

Propagation of AP? what direction?

Answer 48

Bi-directional

Question 49

Each nerve can send how many inpuses before loosing enough ions to cease to function

Answer 49

100,000 to 50,000,000