Why must the kidneys establish a concentration gradient in the interstitial fluid of the renal medulla in order to produce concentrated urine?

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.

Dilute urine is produced when decreased levels of______ are secreted:

a. aldosterone

b. atrial natriuretic peptide

c. ADH

d. none of the above

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.

Trace the pathway taken by a molecule of urea through the kidney from the glomerulus to the renal pelvis if the urea is recycled.

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

Which of the following is NOT a purpose of tubular reabsorption?

Which of the following solutes are primarily reabsorbed by primary active transport?