SHolroydAtWeilCornellMedQatar/Endocrinology/VasopressinADH/EffectOfDecrease

POINT!

With the decrease of the synthesis, secretion, and blood concentration of ADH, the number of water channels decreases .

narrated video explanation

ファイル:ADHbaseline.jpg

video prior to the decrease in ADH
Prior to ADH decreasing (at baseline), we will make the assumption that the subject is in homeostasis with normal plasma and urine osmolarities (isotonic) and volumes.

video just after the increase in ADH
Step 1: Suppose that the synthesis, secretion, and blood concentration of ADH decreases.
The water channel-increasing effect of ADH decreases, thereby decreasing the number of water channels. This decreases the reabsorption of water by the kidney.

video showing the changes in plasma and urine after the increase in ADH
The ratio of Na⁺ to water entering the plasma due to reabsorption increases. This increases plasma osmolarity (hypertonic). Because a higher ratio of Na⁺ to water leaves the tubule due to reabsorption, the fluid remaining in the tubule has a lower osmolarity (hypotonic). Also, with a decrease in water reabsorption, there is more water remaining in the tubule. Overall, the urine becomes less concentrated (hypotonic) and higher in volume.

Challenge Quiz

1.

With sweating, negative feedback increases decreases  正解! the synthesis, secretion, and blood concentration of ADH.

2.

With sweating, negative feedback increases decreases  正解! the number of water channels in the kidney.

3.

With sweating, negative feedback increases decreases  正解! water reabsorption by the kidney.

4.

With sweating, negative feedback increases decreases  正解! urine volume.

5.

With sweating, negative feedback increases decreases  正解! urine osmolarity.

6.

With sweating, negative feedback increases decreases  正解! plasma osmolarity.

7.

With sweating, the plasma osmolarity decreases increases  正解!. The effect would be the same as opposite to  正解! that of reabsorption of water by the kidney, which decreases increases  正解! plasma osmolarity. The effect of the reabsorption would be too weak too strong  正解! prior to control by negative feedback. Negative feedback increases decreases  正解! the synthesis, secretion, and blood concentration of ADH. This in turn increases decreases  正解! the number of water channels in the kidney causing increased decreased  正解! water reabsorption. Urine osmolarity increases decreases  正解! while volume increases decreases  正解!. This decreases increases  正解! plasma osmolarity, returning to normal separating from normal  正解!.