Which hormone secreted by the kidney is responsible

Water moves out of the kidney tubules through the aquaporins, reducing urine volume. The water is reabsorbed into the capillaries lowering blood osmolarity back toward normal. As blood osmolarity decreases, a negative feedback mechanism reduces osmoreceptor activity in the hypothalamus, and ADH secretion is reduced. ADH release can be reduced by certain substances, including alcohol, which can cause increased urine production and dehydration.

If the posterior pituitary does not release enough ADH, water cannot be retained by the kidneys and is lost as urine. This causes increased thirst, but water taken in is lost again and must be continually consumed. If the condition is not severe, dehydration may not occur, but severe cases can lead to electrolyte imbalances due to dehydration. Another hormone responsible for maintaining electrolyte concentrations in extracellular fluids is aldosterone , a steroid hormone that is produced by the adrenal cortex.

Aldosterone release is stimulated by a decrease in blood sodium levels, blood volume, or blood pressure, or an increase in blood potassium levels. Aldosterone production can be stimulated by low blood pressure, which triggers a sequence of chemical release, as illustrated in Figure 1.

When blood pressure drops, the renin-angiotensin-aldosterone system RAAS is activated. Adrenal glands produce hormones that help regulate your metabolism, immune system, blood pressure, response to stress and other essential functions. Adrenal glands are composed of two parts — the cortex and the medulla — which are each responsible for producing different hormones.

Adrenal glands may develop nodules that can be benign or malignant, which can potentially produce excessive amounts of certain hormones leading to various health issues.

The adrenal cortex is the outer region and also the largest part of an adrenal gland. It is divided into three separate zones: zona glomerulosa, zona fasciculata and zona reticularis. Each zone is responsible for producing specific hormones. The adrenal medulla is located inside the adrenal cortex in the center of an adrenal gland. The adrenal cortex and adrenal medulla are enveloped in an adipose capsule that forms a protective layer around an adrenal gland.

The role of the adrenal glands in your body is to release certain hormones directly into the bloodstream. Many of these hormones have to do with how the body responds to stress, and some are vital to existence. Both parts of the adrenal glands — the adrenal cortex and the adrenal medulla — perform distinct and separate functions.

Each zone of the adrenal cortex secretes a specific hormone. The key hormones produced by the adrenal cortex include:. Cortisol is a glucocorticoid hormone produced by the zona fasciculata that plays several important roles in the body. It is released during times of stress to help your body get an energy boost and better handle an emergency situation. Adrenal glands produce hormones in response to signals from the pituitary gland in the brain, which reacts to signaling from the hypothalamus, also located in the brain.

This is referred to as the hypothalamic pituitary adrenal axis. As an example, for the adrenal gland to produce cortisol, the following occurs:. The hypothalamus produces corticotropin-releasing hormone CRH that stimulates the pituitary gland to secrete adrenocorticotropin hormone ACTH.

The single most important effect of antidiuretic hormone is to conserve body water by reducing the loss of water in urine. A diuretic is an agent that increases the rate of urine formation. Injection of small amounts of antidiuretic hormone into a person or animal results in antidiuresis or decreased formation of urine, and the hormone was named for this effect.

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.

Antidiuretic hormone stimulates water reabsorbtion by stimulating insertion of "water channels" or aquaporins into the membranes of kidney tubules. These channels transport solute-free water through tubular cells and back into blood, leading to a decrease in plasma osmolarity and an increase osmolarity of urine.

In many species, high concentrations of antidiuretic hormone cause widespread constriction of arterioles, which leads to increased arterial pressure. It was for this effect that the name vasopressin was coined.

In healthy humans, antidiuretic hormone has minimal pressor effects. They activate vitamin D, which helps to maintain strong bones, and produce erythropoietin, a hormone that is vital for the production of red blood cells.

Each kidney contains 1. The kidneys filter blood through a network of small blood vessels called the glomerulus. This produces a solution that then flows through the nephrons. As this fluid passes through the nephron, substances that the body wants to retain such as sodium, potassium, proteins and most of the water are re-absorbed back into the blood.

The substances that need to be removed from the body, such as waste products including the remains of drugs and alcohol, are retained in the fluid and removed from the body in the form of urine. The kidneys filter around litres of blood a day and produce between one to two litres of urine. Vitamin D is essential for a number of different functions in the body.

Most of the vitamin D that is in the blood is inactive and it is modified by the kidney and other tissues to activate it.