Physiology

Question 1

Fluid: total body weight

Answer 1

40% nonwater vs. 60% total body water

Question 2

Fluid: 60% of total body water

Answer 2

1/3 ECF vs. 2/3 ICF

Question 3

Fluid: 1/3 of ECF

Answer 3

1/4 plasma vs. 3/4 interstitial

Question 4

Fluid: rules

Answer 4

60-40-20 rule (% of body weight)

60%: total body water
40%: ICF
20%: ECF

Question 5

Fluid: characteristics

Answer 5

High K in intracellular
“HIKIN”

Osmolarity= 290mOsm/L

Plasma volume measured by radiolabeled albumin
Extracellular volume measured by inulin

Question 6

Glomerular filtration barrier

Answer 6

Filtration according to size and net charge:

Composed of

1) fenestrated capillary endo (size barrier)
2) fused basement membrane with heparan sulfate (negative charge barrier)
3) epithelial layer consisting of podocyte foot process

Question 7

What is lost in nephrotic syndrome, and consequence?

Answer 7

The charged barrier (basement membrane) lost

Results: albuminuria, hypoproteinema, generalized edema, and hyperlipidemia

Question 8

Glucose clearance

Answer 8

Glucosuria begins at plasma glucose of ~160mg/dL

At 350mg/dL, all transporters are all saturated (Tm)

Question 9

Normal pregnancy and its effect on glucose and AA

Answer 9

Normal pregnancy reduces reabsorption of glucose and amino acids in the proximal tubule

This leads to glucosuria and aminoaciduria

Question 10

Amino acid clearance

Answer 10

Na-dependent transporters in proximal tubule reabsorb AA

Hartnup’s disease: deficiency of neutral AA (tryptophan) transporter, results in pellagra