25. The Urinary System

Renal Physiology Step 2: Tubular Reabsorption

Open Question
Describe what is involved in active and passive tubular reabsorption.
Open Question
Tubular reabsorptiona. of glucose and many other substances is a Tₘ -limited active transport process,b. of chloride is always linked to the passive transport of Na⁺ ,c. is the movement of substances from the blood into the nephron,d. of sodium occurs only in the proximal tubule.
Open Question
Which is reabsorbed by the proximal convoluted tubule cells?a. Na⁺,b. K⁺,c. amino acids,d. all of the above.
Open Question
Two physiology students are having a disagreement about renal function. Dan says that the kidneys work harder when you eat a high-salt diet, whereas Peter says that they work harder when you drink lots of water. Who is right, and why?
Open Question
Trace the pathway a uric acid molecule takes from a glomerulus to the urethra. Name every gross or microscopic structure it passes through on its journey.
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Sodium ions and glucose are cotransported into the proximal tubule cell by secondary active transport.
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. The distal tubule reabsorbs sodium ions and secretes potassium and hydrogen ions in response to ADH.
Open Question
Dilute urine is produced when decreased levels of______ are secreted:

a. aldosterone
b. atrial natriuretic peptide
c. ADH
d. none of the above
Open Question
Fill in the blanks: The kidneys produce _____ urine when the osmolarity of the body's fluids increases. They produce _____urine when the osmolarity of the body's fluids decreases.
Open Question
Trace the pathway taken by a molecule of urea through the kidney from the glomerulus to the renal pelvis if the urea is recycled.
Open Question
Why must the kidneys establish a concentration gradient in the interstitial fluid of the renal medulla in order to produce concentrated urine?
Open Question
Drugs that treat hypertension, or high blood pressure, have the following actions. Discuss the specific effect that each drug will have on the kidneys.

c. Blocking the Na+/Cl−/2K+ transport pumps in the thick ascending limb of the nephron loop
Open Question
How does aldosterone modify the chemical composition of urine?