Regulation of water in the body ( Homeostasis Episode 3)

DID U KNOW THATUp to 60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water.This video explains to you very well what the body does in order to ensure that water in your body is neither in excess nor inadequate.

Water regulation in the body is essential for maintaining proper cellular function, blood volume, and electrolyte balance. Several organs and hormones work together to regulate water in the body. Here are some key aspects of water regulation:

1. The hypothalamus: The hypothalamus in the brain senses changes in blood osmolality, or the concentration of particles in the blood. When the osmolality increases, the hypothalamus stimulates the release of antidiuretic hormone (ADH) from the pituitary gland.

2. ADH: ADH, also known as vasopressin, is a hormone that regulates water reabsorption in the kidneys. ADH acts on the kidneys to increase the reabsorption of water, leading to decreased urine output and increased water retention. When blood osmolality decreases, ADH release is inhibited, and the kidneys excrete more water, leading to increased urine output and decreased water retention.

3. Kidneys: The kidneys play a critical role in regulating water balance in the body. The kidneys filter waste products and excess water from the blood, which is then excreted as urine. The amount of water reabsorbed in the kidneys is regulated by ADH, as described above.

4. Thirst mechanism: The sensation of thirst is an important mechanism for regulating water balance. When dehydration occurs, the body senses a decrease in blood volume, which triggers the release of hormones that stimulate thirst, leading to increased water intake.

5. Electrolyte balance: Regulating water balance also involves maintaining electrolyte balance. Electrolytes, such as sodium, potassium, and chloride, are essential for proper cellular function, and their concentrations are carefully regulated by the kidneys and several hormones.

Disruptions to the regulation of water balance can lead to various disorders, such as dehydration or overhydration, which can have significant effects on electrolyte balance and cellular function.