How does vasopressin cause water to be reabsorbed across the collecting duct epithelium?
What will be an ideal response?
Answer: Vasopressin binds to receptors on the basolateral membrane, acting through adenyl cyclase to raise cytoplasmic cAMP, triggering phosphorylation of proteins that cause aquaporins to be inserted into the apical membrane of the collecting duct cells. Water then flows by osmosis from the lumen of the collecting duct, through the aquaporins and epithelium into the interstitial fluid, driven by the high osmotic pressures of the medullary interstitium.
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Which muscle(s) of respiration is(are) innervated by the phrenic nerve?
A. Diaphragm B. External intercostals C. Internal intercostals D. Innermost intercostals E. Pectoralis major
Blood returning to the heart from the systemic circulation drains via the superior vena cava and the ________.
Fill in the blank(s) with the appropriate word(s).
Measurement of arterial pressure using a sphygmomanometer is possible because turbulent blood flow that occurs as arterial pressure overcomes a partially occluded artery and can be heard by a stethoscope placed just over the artery
Indicate whether the statement is true or false
Simple diffusion requires:
A) protein channels. B) a concentration gradient. C) the use of energy. D) carrier proteins.