Control of kidney function
The activity of the nephron in the kidney is controlled by a person’s choices and environment as well as hormones. For example, if a person consumes large amounts of protein, much urea will be in the blood from the digestion of the protein. Also, on a hot day, a body will retain water for sweating and cooling, so the amount of urine is reduced.
Humans produce a hormone called antidiuretic hormone (ADH), also known as vasopressin, which is secreted by the posterior lobe of the pituitary gland. It regulates the amount of urine by controlling the rate of water absorption in the nephron tubules.
Some individuals suffer from a condition in which they secrete very low levels of ADH. The result is excessive urination and a disease called diabetes insipidus. Another unrelated form of diabetes, diabetes mellitus, is more widespread. People with this disease produce insufficient levels of insulin. Insulin normally transports glucose molecules into the cells. But when insulin is not available, the glucose remains in the bloodstream. The glucose is removed from the bloodstream in the nephron; to dilute the glucose, the nephron removes large amounts of water from the blood. Thus, the urine tends to be plentiful.
Hormones from the cortex of the adrenal glands also control the content of urine. These hormones promote reabsorption of sodium and chloride ions in the tubules. Thus, they affect the water balance in the body because water flows in the direction of high sodium and chloride content.
Control of kidney functionThe activity of the nephron in the kidney is controlled by a person’s choices and environment as well as hormones. For example, if a person consumes large amounts of protein, much urea will be in the blood from the digestion of the protein. Also, on a hot day, a body will retain water for sweating and cooling, so the amount of urine is reduced.Humans produce a hormone called antidiuretic hormone (ADH), also known as vasopressin, which is secreted by the posterior lobe of the pituitary gland. It regulates the amount of urine by controlling the rate of water absorption in the nephron tubules.Some individuals suffer from a condition in which they secrete very low levels of ADH. The result is excessive urination and a disease called diabetes insipidus. Another unrelated form of diabetes, diabetes mellitus, is more widespread. People with this disease produce insufficient levels of insulin. Insulin normally transports glucose molecules into the cells. But when insulin is not available, the glucose remains in the bloodstream. The glucose is removed from the bloodstream in the nephron; to dilute the glucose, the nephron removes large amounts of water from the blood. Thus, the urine tends to be plentiful.Hormones from the cortex of the adrenal glands also control the content of urine. These hormones promote reabsorption of sodium and chloride ions in the tubules. Thus, they affect the water balance in the body because water flows in the direction of high sodium and chloride content.
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