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, low-capacity, high-affinity transport of glucose takes place in this region of the nephron:
(2) In the kidneys, high-capacity, low-affinity transport of glucose is accomplished by this transport protein:
(3) In the kidneys, low-capacity, high-affinity transport of glucose is accomplished by this transport protein:
(4) The ion/substrate stoichiometry is 2 Na+ : 1 glucose for the Na+/glucose cotransporter 1 (SGLT1), whereas that for the Na+/glucose cotransporter 2 (SGLT2) is 1 Na+ : 1 glucose. Given this information, which isoform has a higher concentrative capacity (i.e., achieves a higher glucose concentration gradient by accumulating more glucose inside the cell relative to the concentration outside the cell).
(5) The kidneys comprise about 0.5% of the total body weight, however, they receive __________ of the cardiac output.