Question

16. A human nephron A. is one of the two kidneys B. is the functional excretory unit C. is about the size of your fist D. all of the above

17. The proximal convoluted tubule A. is lined by microvilli B. excrete salt ions of sodium and potassium C. secretes unneeded proteins D. absorbs organic acids

18. Urine entering the collecting duct A. will have salt added as it descends B. will have urea added as it descends C. will have water added as it descends D. none of the above

19. The multiplier effect A. increases the salt concentration of the cortex B. decreases the salt concentration of the urine C. is due to the absorption of salt into the urine D. none of the above

20. Alcohol and caffeine increase urine volume by
A. decreasing blood pressure and increasing ADH production
B. increasing blood pressure and decreasing ADH production
C. increasing blood pressure and increasing ADH production
D. decreasing blood pressure and decreasing ADH production

Answer 1

16) (B) is the functional excretory unit

- Human Kidney lie on the either side of the spine in the retroperitoneal space. They are roughly the size of our fist. There are about 1.3 million nephrons in each kidney. Nephron are the 'functional unit' of kidney.They cleanses the blood and balances the constituents of the circulation.

17) (A) is lined by microvilli

- PCT is responsible for secreting Organic acids. Sodium reabsorption is primarily functioned by PCT. PCT has a simple tall cuboidal epithelium with brush border (i.e., microvilli).

18) (B) will have urea added as it descends

19) (A) increases the salt concentration of the cortex

- the multiplier term is used because of the action of solute pumps that increases the concentration of Urea and Sodium ( Na+) deep in medula and cortex.

20) (D) decreasing blood pressure and decreasing ADH production

- when alcohol is around, less ADH is released, which translates to more urine leaving the body.

Alcohol also reduces the production of vasopressin hormone. If you don't have enough vasopressin, yaar Kidneys excrete too much of water. Which causes frequent urination.