Karius - everything

Question 1

what does the Na+/K+ pump?

Answer 1

3 Na out

2 K in

Question 2

if nernst is greater (abs value) which gradient dominates?

Answer 2

chemical

Question 3

what kind of channels are Cl?

what nt’s bind to open the channel?

Answer 3

Ligand-gated

GABA and Glycine

Question 4

what controls which way ions flow through a channel?

Answer 4

ionic gradient

Question 5

describe the ClC1 channel

Answer 5

open at rest

closes with depol

Question 6

what are are the sodium channels like during threshold?

Answer 6

all of them are open

Question 7

is it possible to get an AP during absolute refractory period?

Answer 7

NO

Question 8

what happens in a relative refractory period?

Answer 8

harder to get 2nd AP, some Na channels back to closed state

Question 9

what is a depolarization block?

Answer 9

voltage inactivation

something external is holding Vm more depol than normal ie. drug

Question 10

how do most APs travel?

Answer 10

via saltatory conduction

Question 11

what is the result of hyperkalemia?

Answer 11

high K+ in ECF, renal failure, may see a depolarization

Question 12

what is conduction velocity = to?

Answer 12

mm / time

Question 13

do AP die away with time or distance?

Answer 13

NO

Question 14

what is used in direct electrical/chemical communication?

what is the route of transmission?

Answer 14

gap junctions

Intracellular fluid

Question 15

what are the post-synaptic specializations?

Answer 15

extensive surface area

post-synaptic densities (NT receptors)

Question 16

what are presynaptic specializations?

Answer 16

mitochondria
vesicles
increased surface area

Question 17

what are the adrenergic nts?

Answer 17

SEND H

serotonin
epi
norepi
dopamine
histamine

Question 18

excitatory a.a.?

Answer 18

glutamate

aspartate

Question 19

inhibitor a.a.?

Answer 19

glycine (spinal cord, brainstem)

GABA (CNS)

Question 20

describe nt release

Answer 20

depol of pre-synaptic term
opening of VG-Ca channels
Ca influx into terminal
binding of Ca
conformation change in proteins brings docked vesicles
fusion of vesicular membrane with CM
creation of fusion pore
diffusion of nt into cleft

Question 21

how is nt remvoed from cleft?

Answer 21

diffusion
natural (NO)
enzymatically via AChE
Re-uptake via Epi/NorEpi

Question 22

what happens if the nt opens a Na or Ca channel?

what is the nt?

Answer 22

depol
then EPSP

ACh or EAA

Question 23

what happens if nt opens a Cl channel?

what is the nt?

Answer 23

Cl enters cell
hyperpol

IPSP

GABA or glycine

Question 24

describe temporal summation

Answer 24

axon has multiple AP traveling with it

both + or both -

Question 25

describe spatial summation

Answer 25

2 or more synapses simulatenously active | EPSP and IPSP can be ADDED

Question 26

what is located on the T-tubule?

Answer 26

DHP receptor

Question 27

where is the ryanodine receptor located? are they voltage gated?

Answer 27

terminal cisternae (SR) NO

Question 28

with depol of the t-tubule membrane, what happens?

Answer 28

Ca is released from the SR and diffuses to area of myofibrils

Question 29

at rest what is blocking the active sites?

Answer 29

tropomyosin

Question 30

how is tropomyosin moved out of the way?

Answer 30

Ca binds troponin C, it undergoes conformational change and moves tropomyosin out of the way

Question 31

what happens after tropomyosin is out of the way?

Answer 31

Pi will dissociate from the myosin head

Question 32

what happens after Pi dissociates?

Answer 32

ADP dissociates to create the powerstroke

Question 33

what happens when ATP binds the myosin head?

Answer 33

conformational change so that myosin and actin dissociate

Question 34

what does energy due to the myosin?

Answer 34

moves the head back into cocked position

Question 35

when does the powerstroke process stop?

Answer 35

no more ATP or Ca Ca-ATPase removes Ca from cytoplasm mechanical forces prevent contraction

Question 36

where is CrP made? ATP production? when is it used?

Answer 36

at myofibril 1:1 during exercise

Question 37

failure to maintain the energy supply causes fatigue do to what?

Answer 37

nt at NMJ used up | inadequate ATP available

Question 38

how is creatine made?

Answer 38

CrP + ADP --> Cr + ATP

Question 39

what 2 things are required for an ionic gradient?

Answer 39

selective cell membrane | Na/K ATPase