AP BIOLOGY

Detailed explanation-1: -Antidiuretic hormone binds to receptors on cells in the collecting ducts of the kidney and promotes reabsorption of water back into the circulation. In the absense of antidiuretic hormone, the collecting ducts are virtually impermiable to water, and it flows out as urine.

Detailed explanation-2: -Antidiuretic Hormone (ADH) The target cells of ADH are located in the tubular cells of the kidneys. Its effect is to increase epithelial permeability to water, allowing increased water reabsorption.

Detailed explanation-3: -Explanation: ADH acts upon the collecting ducts and distal convoluted tubules of nephrons to increase water reabsorption. It causes an increase in the number of aquaporins in order to allow for this.

Detailed explanation-4: -The main action of ADH in the kidney is to regulate the volume and osmolarity of the urine. Specifically, it acts in the distal convoluted tubule (DCT) and collecting ducts (CD). During states of increased plasma osmolality, ADH secretion is increased.

Detailed explanation-5: -ADH primarily affects the ability of the kidney to reabsorb water; when present, ADH induces expression of water transport proteins in the late distal tubule and collecting duct to increase water reabsorption.