Cellular Physiology

Question 1

What is the total body water % of a 70kg man?

Answer 1

60%

Question 2

Of the total body water % of a 70kg man, what is ICF and ECF?

Answer 2

40% = ICF
20% = ECF

Question 3

How can ICF be calculated?

Answer 3

total body water - extracellular fluid

Question 4

What relationship has ECF and ICF have at osmotic equilibrium?

Answer 4

iso-osmotoc

Question 5

what is ECF best measured using?

Answer 5

inulin
- polysaccharide
- MW5200

Question 6

what is total body water inversely proportional to?

Answer 6

fat
therefore, reduced in cushings disease

Question 7

what are the 4 properties of plasma membrane?

Answer 7

semi-permeable membrane

preferential permeability to lipid-soluble substances

low surface tension

high electrical resistance (therefore basically impermeable to organic anions)

Question 8

what are the x4 ways a substance can cross a membrane?

Answer 8

diffusion

endocytosis

exocytosis

transport proteins

Question 9

what is endocytosis associated with?

Answer 9

clathrin

Question 10

when does equilibrium potential across a membrane for any particular ion exist?

Answer 10

when there is no net passive movement of the ion across the membrane

Question 11

what is the resting membrane potential of a nerve or muscle?

Answer 11

-70 to -90 mV

Question 12

what is greater permeability - Na Vs K?

Answer 12

K+ > Na+

Question 13

what does insulin cause in cell potential?

Answer 13

increase in resting membrane potential
- hyperpolarisation

Question 14

what is the liver readily permeable to?

Answer 14

plasma proteins

Question 15

how does glucose transfer occur?

Answer 15

passive diffusion

Question 16

why does scurvy associated with blood vessel fragility?

Answer 16

because

ascorbic acid is an essential co factor for the synthesis of collagen

Question 17

what is the gibbs donnan effect?

Answer 17

when an ion on one side of the membrane cannot diffuse across, the distribution of the other ions will move appropriately to balance the charge

Question 18

why are the Cl- levels in the interstitial fluid higher than in the blood plasma?

Answer 18

because

capillary membranes are not freely permeable to protein anions

Question 19

in interstitial fluid what is the main anion inside the cell?

Answer 19

organic phosphates

Question 20

what is found in higher concentrations in the plasma than in the interstitial fluid?

Answer 20

higher sodium

higher magnesium

higher protein