Basic Physiological Principles

Question 1

mMol/L

Answer 1

How many molecules of substance/L. (mg/mw)/L

Question 2

mEq/L

Answer 2

Ionic charge
mMol/L * Valence * number of ions in molecule

Ca has 1 ion in CaCl2

Question 3

mOsm/L

Answer 3

mMol/L * total # of particles in molecule

CaCl2 has 3 particles

Question 4

% Solution

Answer 4

Amount of a substance in g per 100mL solvent.

Question 5

% Solution Saline

Answer 5

0.9% Na

Question 6

Total Body Fluid in L, how is it divided up?

Answer 6

40 L. 25 in cells, 15 EC, 5 in vasculature

Question 7

Concentration of sodium EC and in skeletal muscle

Answer 7

~140 mEq/L EC, ~10 mEq/L

Question 8

Concentration of K EC and in skeletal muscle

Answer 8

~4 mEq/L EC, ~145 mEq/L IC

Question 9

Counter ion for HCO3-

Answer 9

IC proteins, which are negatively charged at physiological pH.

Question 10

How does the body deal with osmotic imbalance?

Answer 10

Moves water to equilibrate rapidly.

Question 11

Daily loss of water due to urine

Answer 11

Decreases with exercise and hot weather. Designed to account for loss via other routes.

Question 12

Loss of water in feces

Answer 12

Remains relatively constant.

Question 13

Two characteristics of osmotic particles

Answer 13

Must be dissolved and contained by semipermeable membrane.

Question 14

Does sodium contribute to osmotic pressure of capillaries?

Answer 14

No, because it can pass through, but it does contribute with cell membranes.

Question 15

Is a 10 mOsm/L difference big or small?

Answer 15

Big, 1 mOsm is 19.3 mmHg.

Question 16

Solutes that stay extracellular

Answer 16

NaCl, NaHCO3, large sugars

Question 17

Solutes that go intracellular

Answer 17

K, small sugars (glucose)

Question 18

What happens when normal saline is infused?

Answer 18

Isotonic solution, 0.9% NaCl, which will stay EC. Goes from vasculature to interstitium, not taken up. Water distributes with the salt. Does not change the osmolarity of the solution.

Question 19

What happens with high NaCl intake?

Answer 19

Salt into GI tract, rapidly taken into bloodstream, distributes to extracellular volume, does not go IC. Concentration of EC fluid increases. Driving force pulls water out to cells to decrease the concentration in EC space. Osmotic concentration in cells subsequently increases.

Question 20

What happens when volume is lost due to diarrhea?

Answer 20

GI secretions (with the exception of the mouth) are isotonic. Volume contraction occurs, but there is no ionic composition change. Fluid comes from EC space. No driving force, no loss of IC volume.

Question 21

Paracellular Transport

Answer 21

Between cells, through tight junctions.

Question 22

Transcellular Transport

Answer 22

Through cells, dictated by the population of apical protein transporters and basolateral protein transporters.

Question 23

How is water transported through epithelial cells?

Answer 23

Aquaporins.

Question 24

Solvent drag

Answer 24

Driving force for water movement, anything dissolved in it will get pulled. RBC’s included.