Cellular Physiology Pt 2

Question 1

Atrial natriuretic peptide (ANP) and nitric oxide (NO) act through _________ that converts GDP to _________ which is the second messenger

Answer 1

Guanylyl cyclase; cyclic GMP

Question 2

Insulin acts through _____ _____

Answer 2

Tyrosine kinase

Question 3

Associated with enzymatic activity in receptors (no G proteins)

Answer 3

Catalytic receptor mechanism

Question 4

How do beta 2 stimulants affect lungs?

Answer 4

Terbutaline— acts on receptors via Gs protein, activates adenyl cyclase which increases cAMP.

cAMP activates protein kinases which cause brinchodilation

Question 5

How do phosphodiasterase inhibitors affect lungs? (Aminophylline)

Answer 5

Inhibit breakdown of cAMP, meaning increased cAMP levels, more protein kinase, bronchodilation

Question 6

How does ipratropium (Atrovent) affect lungs?

Answer 6

Inhibits inhibits M3 (cholinergic miscarinic) receptor leading to bronchodilation

Question 7

What causes bronchoconstriction?

Answer 7

Stimulation of M3 receptor and G protein causes formation of IP3 which releases Ca from ER

Question 8

cAMP Mechanism drugs/hormones

Answer 8

ACTH
LH, FSH
TSH
ADH (V2 receptor)
HCG
B1 & B2 receptor
A2 receptor 
Calcitonin
PTH
Glucagon
Muscarinic (M2)

Question 9

IP3 mechanism list

Answer 9

GnRH
TRH
GHRH
ADH (V1 receptor)
Oxytocin
A1 receptor
Angiotensin-II
Muscarinic: (M1, M3)

Question 10

Steroid hormone mechanism list

Answer 10

Glucocorticoids
Estrogen
Testosterone
Progesterone
Aldosterone
Vitamin D
Thyroid hormone

Question 11

Activation of tyrosine kinase

Answer 11

Insulin

IGF-1

Question 12

cGMP

Answer 12

Nitric oxide (NO)
ANP

Question 13

Opening of Na/K pump channels

Answer 13

Nicotinic:
Nm (N1)
Nn (N2)

Question 14

Upstroke of action potential

Answer 14

Na moving into the cell

Question 15

Downstroke of action potential

Answer 15

K moving out of the cell

Question 16

What causes resting membrane potential?

Answer 16

Leaky K channels

Question 17

Absolute refractory period

Answer 17

Period when another action potential CANNOT be elicited

Question 18

Relative refractory period

Answer 18

Period when an action potential can be elicited by larger than usual stimulus

Question 19

________ protects the cell from over-excitation and allows a recovery period between the action potentials

Answer 19

Refractory period

Question 20

______ inhibit Na/K pump leading to hyperkalemia

Answer 20

Beta blockers

Question 21

Are continuous with the cell membrane

Invaginate the cells at the Z lines and carry AP into the cell interior

Answer 21

T tubules

Question 22

Site of storage and release of Ca++ for excitation-contraction coupling

Answer 22

Sarcoplasmic reticulum

Question 23

______ block entry of Ca in L-type calcium channels. How does it affect HR?

Answer 23

CCB; HR slows down

Question 24

Why do cardiac cells not respond to tetanus?

Answer 24

They have high refractory period and will not respond to the stimuli

Question 25

A series of myosin head movements that result in sustained contraction

Answer 25

Tetany

Question 26

MOA dobutamine

Answer 26

Beta agonist

Increases cAMP, activation of protein kinase, increased Ca into myocardial cell, increased force of contraction

Question 27

MOA beta blockers

Answer 27

Inhibit Na/K pump. K stays extracellular and can cause hyperkalemia

Question 28

Caffeine, aminophylline, milrinone MOA

Answer 28

Phosphodiasterase inhibitors. Decrease breakdown of cAMP

Question 29

Diltiazem MOA

Answer 29

CCB. Block entry of Ca through L-type (dihydropyridine receptors) channels. Decreases HR

Question 30

Dantrolene MOA

Answer 30

Blocks Ca release channels (ryanodine receptors) on sarcoplasmic reticulum