Is reabsorption of water hormonally controlled?

Yes, reabsorption of water in the kidneys is hormonally controlled, primarily by the antidiuretic hormone (ADH), also known as vasopressin. ADH is produced by the hypothalamus and released from the posterior pituitary gland. It plays a crucial role in regulating water balance and maintaining the body's fluid homeostasis.

ADH acts on the collecting ducts in the kidneys, increasing the permeability of the duct cells to water. This allows water to be reabsorbed from the urine back into the bloodstream. As a result, urine becomes more concentrated, and less water is excreted from the body.

The release of ADH is regulated by the body's fluid status and blood pressure. When the body is dehydrated or blood pressure drops, ADH secretion increases, leading to increased water reabsorption and decreased urine output. This helps conserve water and maintain blood volume.

Conversely, when the body is adequately hydrated or blood pressure is high, ADH secretion decreases, resulting in reduced water reabsorption and increased urine output. This allows the body to eliminate excess water and maintain fluid balance.

The hormonal control of water reabsorption by ADH is essential for maintaining the body's water homeostasis and preventing dehydration or excessive water loss.