BY 32 – SPRING 2002

LECTURE 21: PHYSIOLOGY OF THE URINARY SYSTEM II: TUBULAR REABSORPTION AND SECRETION

Study Outline

Answers

21.1. General Principles:

a. proximal tubule

b. paracellular; transcellular

c. Paracellular reabsorption; transcellular reabsorption

d. passive; electrochemical; osmosis

e. Na⁺/K⁺ ATPase; basolateral; against

f. Na⁺; symporter; antiporter

g. transport maximum; glucosuria

h. down; energy; diffusion; facilitated diffusion; osmosis

i. passive; osmosis; obligatory; facultative water reabsorption

21.2. Reabsorption and Secretion along the Proximal Tubule:

a. 65-70; 65-70; glucose; lactate; amino acids

b. 1; 2; facilitated diffusion; Na⁺/K⁺ ATPase

c. amino acids; lactic acid; water soluble vitamins

d. 1; carbonic anhydrase; Na⁺; HCO₃^-

e. solvent drag

f. ammonia; urea

21.3. Reabsorption in the Loop of Henle and Distal Tubule:

a. descending; ascending limb

b. 1; 1; 2

c. similar; less

d. low; decrease

e. Na⁺-Cl^- symporter

21.4. Reabsorption along the Collecting Ducts:

a. principal; intercalated

b. enters; leaves

c. increases; decreases; aldosterone;

d. H⁺ATPase; carbonic anhydrase; a Cl^-/HCO₃^- antiporter

21.5. Hormonal Regulation of Tubular Reabsorption and Secretion:

a. angiotensin II; aldosterone; ADH; ANP

b. Na⁺; Cl^-; water; aldosterone

c. principal; K⁺ secretion

d. increase; water; low

e. ANP; increases; decrease; decrease; increases

21.6. Production of Dilute and Concentrated Urine:

a. same; proximal tubule

b. increases; leaves

c. decreases; low; low

d. low; high

e. osmotic; solute and water permeabilities of the loop of Henle and Collecting ducts; countercurrent mechanisms

f. Na⁺-K⁺-2Cl^- symporters; salt; urea

g. Nutrients; salt

h. Diuretic; ADH; Na⁺; Na⁺-K⁺-2Cl^- symporters; thiazide diuretics

21.7. Evaluation of Kidney Function:

a. Urinalysis

b. renal plasma clearance; zero

c. urine concentration; plasma concentration; urine flow rate

d. GFR; inulin

e. reabsorbed; secreted