Excretion of Dilute Urine

The excretion of dilute urine is regulated by the secretion of vasopressin, also known as antidiuretic hormone (ADH). Vasopressin is produced in the hypothalamus and released by the posterior pituitary gland. It plays a crucial role in regulating the body's water balance by controlling the reabsorption of water in the kidneys.

Effects of Vasopressin
Vasopressin acts on the cells of the distal convoluted tubules and collecting ducts in the nephrons of the kidneys. It increases the permeability of these cells to water, allowing it to be reabsorbed back into the bloodstream. This process is known as water reabsorption.

Increased Vasopressin Secretion
When there is an increased secretion of vasopressin, the cells of the distal convoluted tubules and collecting ducts become more permeable to water. As a result, more water is reabsorbed back into the bloodstream, leading to the production of concentrated urine. This is important in situations where the body needs to conserve water, such as during dehydration or low water intake.

Decreased Vasopressin Secretion
On the other hand, when there is a decreased secretion of vasopressin, the cells of the distal convoluted tubules and collecting ducts become less permeable to water. As a result, less water is reabsorbed back into the bloodstream, and more water is excreted in the urine. This leads to the production of dilute urine.

Answer Explanation
Among the given options, option B states that less secretion of vasopressin is responsible for the excretion of dilute urine. This is the correct answer because when there is a decrease in vasopressin secretion, the cells of the distal convoluted tubules and collecting ducts become less permeable to water, resulting in the excretion of dilute urine. The other options (more secretion of insulin, more secretion of aldosterone, and less secretion of glucagon) are not directly involved in the regulation of water reabsorption and urine concentration.