Cellular Physiology

Question 1

value of resting membrane potential

Answer 1

-55 to -90 mV

Question 2

action potential

Answer 2

all or nothing response

Question 3

depolarizing phase

Answer 3

Na+ channels open and Na+ enters the cell

Question 4

repolarizing phase

Answer 4

Na+ channels close, K+ channels open and K+ exits the cells

Question 5

restoration of membrane potential

Answer 5

Na+/K+ pump restores membrane potential by pumping 3 Na+ out and 2 K+ in (pumpKin)

Question 6

what controls action potential in the heart

Answer 6

calcium (K+ still does repolarization)

Question 7

what hyperpolarizes the cell

Answer 7

GABA is an inhibitory NT that opens Cl- channels, allowing Cl- to enter the cell

Question 8

GABA agonist drug

Answer 8

Diazepam

Question 9

autocrine

Answer 9

cell signals self

Question 10

endocrine

Answer 10

signal travels via blood stream

Question 10

exocrine

Answer 10

into a duct system

Question 10

paracrine

Answer 10

neighboring cell sends signal

Question 10

steps of signaling

Answer 10

recognition, transduction, transmission, modulation, response, termination

Question 11

Ligand-gated ion channels

Answer 11

chemical mediator causes change in voltage
ex: nicotinic acetylcholine and GABA receptors

Question 12

G protein

Answer 12

rely on secondary messenger system
-adenylate cyclase: epinephrine, norepinephrine
- phospholipase C: muscarinic acetylcholine receptor
- phosphodiesterase: ion channels in retina for phototransduction

Question 13

catalytic receptor

Answer 13

insulin receptor

Question 14

intracellular/nuclear receptor

Answer 14

steroids, vit D, thyroid hormone

Question 15

adhering junctions

Answer 15

maintain cell to cell adhesion
ex: zonula/macula adherens

Question 16

tight junctions

Answer 16

block ions and water between cells
ex: zonula/macula occludens