Homeostasis

Question 1

osmolality

Answer 1

solute concentration; water will flow to dilute it

Question 2

Gibbs-Donnan effect

Answer 2

cell pumps cations out and keeps anions in to maintain equal amounts on both sides

Question 3

hypertonic

Answer 3

solution has too many solutes; cells will shrink

Question 4

hypotonic

Answer 4

solution has too few solutes; cells will expand

Question 5

high osmolality

Answer 5

cells have too many solutes; cells will expand

Question 6

low osmolality

Answer 6

cells have too few solutes; cells will shrink

Question 7

short-term regulation (cell shrinkage)

Answer 7

if cells are shrinking: activate NA-H to pump Na in; this will activate Cl-HCO3 to fix pH and Cl will go into cell
water follows NaCl

Question 8

short-term regulation (cell expansion)

Answer 8

if cells expanding; activate K and Cl channels and let ions flow out to reduce solute concentration

Question 9

long-term regulation

Answer 9

idiogenic osmolytes: made by cell in response to hyperosmolality (cells expanding); are usually sugars
no use of Na, K, Cl in long run because it disrupts cell processes

Question 10

Intracellular Metabolic acidosis

Answer 10

pH is too acidic, too low

activate Na-H exchanger to push H out

Question 11

Intracellular Metabolic alkalosis

Answer 11

pH is too basic, too high

activate Cl-HCO3 to bring HCO3 in and neutralize H conc

Question 12

Intracellular Respiratory Acidosis

Answer 12

too much CO2 comes in from air; this leads to an increase in HCO3 and H concentrations
cell pH drops rapidly. Na-H exchanger activates first and Cl-HCO3 will activate to fix the alkalinized cell

Question 13

Extrinsic buffering

Answer 13

open; does main buffering in body; CO2/HCO3 KEY

Question 14

Intrinsic buffering

Answer 14

closed; usually proteins protonated and act as buggers