GENERAL HISTOLOGY

Detailed explanation-1: -ADH is released by the pituitary gland when the blood is too concentrated and it causes the kidney tubules to become more permeable . This allows more water to be reabsorbed back into the blood during selective reabsorption.

Detailed explanation-2: -Antidiuretic hormone stimulates water reabsorbtion by stimulating insertion of “water channels” or aquaporins into the membranes of kidney tubules. These channels transport solute-free water through tubular cells and back into blood, leading to a decrease in plasma osmolarity and an increase osmolarity of urine.

Detailed explanation-3: -A high ADH level causes the body to produce less urine. A low level results in greater urine production. Normally, the amount of ADH in the body is higher during the night. This helps prevent urination while you are sleeping.

Detailed explanation-4: -The principal action of ADH is to regulate the amount of water excreted by the kidneys. As ADH (which is also known as vasopressin) causes direct water reabsorption from the kidney tubules, salts and wastes are concentrated in what will eventually be excreted as urine.

Detailed explanation-5: -Increased osmolarity increases ADH secretion, leading to reabsorption of water. Salt can be excreted in excess of water, leading to a return toward normal plasma osmolarity. Figure 9.2. 5.