Chapter 13: Membrane Physiology

Question 1

Are structures inside the membrane fat soluble or water soluble?

Answer 1

fat solube

Question 2

Are structures outside the membrane fat soluble or water soluble?

Answer 2

water soluble

Question 3

plasma; fat or water solube?

Answer 3

water

Question 4

cytoplasm; fat or water soluble?

Answer 4

fat

Question 5

Inside a channel, water or fat soluble?

Answer 5

water

Question 6

What is the limiting factor for fat soluble compounds that can get through cell membrane?

Answer 6

concentration gradient; will stop at 50% inside, 50% outside

Question 7

Which hormone’s receptor is in the cytoplasm(but still translocates to nucleus)?

Answer 7

cortisol

Question 8

Which compounds bind to outside receptors and use second messengers?

Answer 8

water soluble

Question 9

easy way to know fat vs water soluble drugs:

Answer 9

how many times it is given per day (half-life); if half-life is short it is water soluble; if half-life is long it is fat soluble

Question 10

Which patients should we be careful when administering a fat soluble drug (long half-life)?

Answer 10

elderly, children, obese, diabetics, hypercholesteremic, pregnant pts.

Question 11

Which labs should you check if pt on fat soluble drug?

Answer 11

liver enzymes, CPK and pancreatic enzymes

Question 12

Which drug has a higher volume of distribution, fat or water soluble?

Answer 12

fat

Question 13

Which drug has a lower volume of distribrution, fat or water soluble?

Answer 13

water

Question 14

Water soluble drugs are excreted by which organ?

Answer 14

kidney

Question 15

What is the one thing we can do to reduce risk of nephrotoxicity while taking water soluble drugs?

Answer 15

maintain adequate hydration and give bicarbs if we want to increase the excretion (water soluble are weak acids)

Question 16

How do you increase the volume of distribution of a water soluble drug?

Answer 16

increase dose (concentration gradient rises)

Question 17

If you want to treat a UTI which kind of drug should you give?

Answer 17

water solube, an acid, shorter half-life (i.e. penicillin, quinolone, tetracycline, etc..)

Question 18

Simple explanation of Fick’s equation:

Answer 18

all factors that favor diffusion go at the top (numerator); all factors that negatively affect diffusion go in the denominator : If the number rises, diffusion rises; if the number gets smaller, diffusion lessens.

Question 19

The two essential fats

Answer 19

linolenic, linoleic

Question 20

What are linolenic acid and linoleic acid used for?

Answer 20

making arachidonic acid (for making leukotreines and prostaglandins)

Question 21

What are the 3 things required for membrane movement?

Answer 21

Ca, ATP, microtubles

Question 22

What is the oxidized protein associated with aging?

Answer 22

thyratron

Question 23

Any sudden development of sebhorrehic keratosis could signal low energy state: what workup should we consider?

Answer 23

HIV, Colon cancer above 40, diabetes under 40 y/0

Question 24

Any development of acanthosis nigricans, what workup should we consider?

Answer 24

GI cancer in older adults; diabetes in young adults or children

Question 25

Do GLUT move in same direction or opposite direction as Na?

Answer 25

same, so they are called symporters

Question 26

Do Ca move in the same direction or opposite as Na?

Answer 26

opposite, so the calcium transporters are called antiporters

Question 27

What is a sympathetic, catabolic second messenger?

Answer 27

cAMP (phosphorylates all proteins); when it dephosphorylates, it becomes parasympathetic

Question 28

What is a parasympathetic, anabolic second messenger?

Answer 28

cGMP (gamma subunite will dissociate and activate guanylate cyclase, protein phosphatase will dephosphorylate all porteins: parasympathetic becomes active, sympathetic becomes inactive

Question 29

What do phophodiesterase inhibitors do?

Answer 29

inhibit breakdown of cAMP by phosphodiaterase (i.e. caffeine, theophylline)

Question 30

Which compounds cannot be given with phosphodiesterase inhibitors?

Answer 30

NO, alpha blockers, hydralazine

Question 31

All hypothalamic hormones (except CRH) and smooth muscle contraction use which second messenger?

Answer 31

IP3-DAG

Question 32

What second messenger does CRH use?

Answer 32

cAMP

Question 33

IP3 causes Ca release from sarcooplasmic reticulum but what has to bind to the Ca to activate Protein Kinase C?

Answer 33

DAG

Question 34

What does Protein kinase C do?

Answer 34

phosphorylates proteins using ATP

Question 35

When smooth muscle distend what do they activate?

Answer 35

calmodulin

Question 36

What kinase do insulin and all growth factors use?

Answer 36

tyrosine kinase

Question 37

What is sirolimus?

Answer 37

tyrosine kinase inhibitor

Question 38

Which amino acid does NO need?

Answer 38

arginine

Question 39

MOA of NO

Answer 39

activates guanylate cyclase which elevates cGMP

Question 40

What does ANP use NO for ?

Answer 40

dilate afferent renal arterioles

Question 41

Best drug for HTN in pregnancy?

Answer 41

Labetalol

Question 42

How do nitrates help heart disease>

Answer 42

venodilation which decreases preload