The kidneys are of outstanding importance. They perform a number of homeostatic functions including filtration of plasma and elimination of metabolic waste products, regulation of the composition and volume of the extracellular fluid, and regulation of blood pressure. The kidneys are also endocrine organs. Test your basic knowledge of renal physiology by taking this simple quiz.
(1) In the kidneys, glucose transport across the apical membrane of epithelial cells of the late proximal tubule (S3) is accomplished by this glucose transporter:
(2) In the kidneys, glucose transport across the basolateral membrane of epithelial cells of the late proximal tubule (S3) is accomplished by this glucose transporter:
(3) The sodium (Na+)/glucose cotransporter 1 (SGLT1) is found in the apical membrane of epithelial cells of the small intestine as well as in the apical membrane of the epithelial cells of the kidney proximal tubules. In the small intestine, SGLT1 is responsible for glucose and galactose absorption across the brush border membrane of small intestinal cells. In the kidney proximal tubules, SGLT1 plays an important role in glucose reabsorption across the brush border membrane of proximal tubular cells. The ion/substrate stoichiometry of SGLT1 is:
(4) The sodium (Na+)/glucose cotransporter 2 (SGLT2) is found in the apical membrane of the epithelial cells of the kidney proximal tubules. SGLT2 plays an important role in glucose reabsorption across the brush border membrane of proximal tubular cells. The ion/substrate stoichiometry of SGLT2 is:
(5) In the kidneys, high-capacity, low-affinity transport of glucose takes place in this region of the nephron: