「SHolroydAtWeilCornellMedQatar/Endocrinology/VasopressinADH/ControlToSweating」の版間の差分
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Step 1: With sweating, water leaves the plasma and osmolarity increases (the plasma becomes hypertonic).<br> | Step 1: With sweating, water leaves the plasma and osmolarity increases (the plasma becomes hypertonic).<br> | ||
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Step 2: ADH, by increasing water channels, and reabsorption of water by the kidney, decreases plasma osmolarity. This is opposite to the effect of sweating. Thus, with the high plasma osmolarity produced by sweating (hypertonic plasma), the baseline strength of the plasma osmolarity-decreasing effect of ADH | Step 2: ADH, by increasing water channels, and reabsorption of water by the kidney, decreases plasma osmolarity. This is opposite to the effect of sweating. Thus, with the high plasma osmolarity produced by sweating (hypertonic plasma), the baseline strength of the plasma osmolarity-decreasing effect of ADH would be too weak. Control by negative feedback is needed. | ||
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Step 3: With the baseline strength of the ADH effect on water channels and reabsorption being too weak, the negative feedback increases the synthesis, secretion, and blood concentration of ADH.<br> | Step 3: With the baseline strength of the ADH effect on water channels and reabsorption being too weak, the negative feedback increases the synthesis, secretion, and blood concentration of ADH.<br> | ||
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Step 4: The | Step 4: The water channel-increasing effect of ADH increases, thereby increasing the number of water channels. This increases the reabsorption of water by the kidney. | ||
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[[ファイル:ADHControlToSweating3Eng.jpg|left|500px]] | [[ファイル:ADHControlToSweating3Eng.jpg|left|500px]] | ||
[[メディア:ADHcontrol-sweat-end.mp4|video showing the changes in plasma and urine after the increase in ADH caused by sweating]]<br> | [[メディア:ADHcontrol-sweat-end.mp4|video showing the changes in plasma and urine after the increase in ADH caused by sweating]]<br> | ||
Step 5: The ratio of Na<sup>+</sup> to water entering the plasma | Step 5: The ratio of Na<sup>+</sup> to water entering the plasma due to reabsorption decreases. This decreases plasma osmolarity. This will lead to the increased plasma osmolarity from sweating (hypertonic plasma) decreasing and returning towards normal (baseline) osmolarity (isotonic plasma). Because a lower ratio of Na<sup>+</sup> to water leaves the tubule due to reabsorption, the fluid remaining in the tubule has a higher osmolarity (hypertonic). Also, with an increase in water reabsorption, there is less water remaining in the tubule. Overall, the urine becomes more concentrated (hypertonic) and lower in volume. | ||
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2019年7月22日 (月) 19:59時点における版
| Following sweating, the plasma osmolarity increases and negative feedback decreases the synthesis, secretion, and blood concentration of ADH. |
video prior to sweating
Prior to sweating (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 sweating
Step 1: With sweating, water leaves the plasma and osmolarity increases (the plasma becomes hypertonic).
Step 2: ADH, by increasing water channels, and reabsorption of water by the kidney, decreases plasma osmolarity. This is opposite to the effect of sweating. Thus, with the high plasma osmolarity produced by sweating (hypertonic plasma), the baseline strength of the plasma osmolarity-decreasing effect of ADH would be too weak. Control by negative feedback is needed.
video just after the increase in ADH caused by sweating
Step 3: With the baseline strength of the ADH effect on water channels and reabsorption being too weak, the negative feedback increases the synthesis, secretion, and blood concentration of ADH.
Step 4: The water channel-increasing effect of ADH increases, thereby increasing the number of water channels. This increases the reabsorption of water by the kidney.
video showing the changes in plasma and urine after the increase in ADH caused by sweating
Step 5: The ratio of Na+ to water entering the plasma due to reabsorption decreases. This decreases plasma osmolarity. This will lead to the increased plasma osmolarity from sweating (hypertonic plasma) decreasing and returning towards normal (baseline) osmolarity (isotonic plasma). Because a lower ratio of Na+ to water leaves the tubule due to reabsorption, the fluid remaining in the tubule has a higher osmolarity (hypertonic). Also, with an increase in water reabsorption, there is less water remaining in the tubule. Overall, the urine becomes more concentrated (hypertonic) and lower in volume.
Challenge Quiz
Following sweating, negative feedback increases decreases (synthesis, secretion, and blood concentration of) ADH.
Following sweating, negative feedback increases decreases water channels in the kidney.
Following sweating, negative feedback increases decreases water reabsorption by the kidney.
Following sweating, negative feedback increases decreases urine volume.
Following sweating, negative feedback increases decreases urine osmolarity.
Following sweating, negative feedback increases decreases plasma osmolarity.
Following sweating, the plasma osmolarity decreases increases . The effect would be the same as opposite to that of ADH, water channels and reabsorption of water by the kidney, which decreases increases plasma osmolarity. The effect of (synthesis, secretion, and blood concentration of) ADH would be too weak too strong prior to control by negative feedback. Negative feedback increases decreases (synthesis, secretion, and blood concentration of) ADH. This in turn increases decreases the number of water channels in the kidney causing increased decreased water reabsorption. Urine osmolarity increases decreases while volume increases decreases . This decreases increases plasma osmolarity, returning to normal separating from normal .