Pituitary: What is it? Structure, Lobes, Function and Associated Problems

Also called the pituitary gland, it controls essential bodily functions and the hormonal system.

It is a protrusion at the base of the brain and the size of a pea or cherry, so it is also called the “pituitary gland” (in Greek, it means “growth attached below”).

The gland is well protected in a small cavity of the bones of the skull, at the level of the nose and in the middle of the head.

The pituitary gland and the hypothalamus, a part of the interbrain, control the involuntary nervous system, which manages the balance of energy, heat, and water in the body.

The body temperature, the heartbeat, and the amount of urine are regulated, and so are sleep, hunger, and thirst.

The pituitary gland also produces a series of hormones that control most of the other hormone glands in the body or directly affect specific organs.


The pituitary gland is made up of four parts:


  • The anterior lobe of the pituitary gland (anterior pituitary gland).
  • The posterior lobe of the pituitary (posterior pituitary).
  • The middle part between both lobes.
  • The pituitary stem forms the connection with the brain.

The anterior and posterior lobes work independently of each other. While the posterior lobe is directly connected to the interbrain (hypothalamus), there is no such connection from the anterior part of the pituitary gland, where the hormones are produced.

Anterior lobe

The anterior lobe constitutes approximately three-quarters of the total mass of the pituitary gland and is formed by glandular tissue. Here two types of hormones are produced:

  1. Hormones that control other hormonal glands.
  2. Hormones have a direct effect on the body.

The group of glands that control hormones includes:

  • The thyroid-stimulating hormone regulates the production of hormones in the thyroid gland.
  • Adrenocorticotropic hormone stimulates the adrenal glands to produce hormones.
  • The follicle-stimulating hormone, regulates the production of hormones in the ovaries and testes.
  • Luteinizing hormone also affects the production of hormones in the ovaries and testes.

The group of hormones that has a direct effect includes:

  • Growth hormone, also called somatotropic hormone, mainly affects the liver and bones, fat, muscle, and many other tissues and organs.
  • Prolactin influences the mammary glands and the ovaries.

Hormones are released by the pituitary gland into the bloodstream and then reach the various organs that they affect.

Thyroid-stimulating hormone, for example, stimulates the thyroid gland to produce more or fewer thyroid hormones, depending on how much is needed.

Prolactin stimulates the growth of the breasts at puberty, activates the production of milk in the breasts, and suppresses ovulation.

Two mechanisms regulate the production of hormones in the anterior lobe:

  1. Liberation or inhibition of hormones produced by the hypothalamus.
  2. Level of hormone in the blood, when the level of thyroid hormones in the body is high enough, the pituitary gland stops producing the hormone that stimulates the thyroid gland.

Posterior lobe

The posterior lobe consists mainly of entangled nerve fibers from the hypothalamus. The rear lobe stores two different hormones, which are released if necessary: ​​oxytocin affects the uterus and the mammary glands.

Vasopressin, also called the antidiuretic hormone, influences the kidney and blood vessels.

In pregnant women, oxytocin causes contractions during delivery, for example. Vasopressin plays a vital role in regulating the amount of water in the body.

Intermediate part

In the middle part between the anterior and posterior pituitary glands, there is also the tissue that produces a hormone: the melanocyte-stimulating hormone or intermediate, which mainly affects the skin but also the nerve cells of the brain.

This hormone stimulates the production of melanin in the skin, a pigment that protects against the sun’s harmful ultraviolet rays. It also regulates our appetite and influences sexual impulses.

Pituitary stem

The pituitary stalk connects the posterior lobe directly with the interbrain, or more precisely, with the hypothalamus.

The function of the pituitary gland

The function of your pituitary gland is twofold; it is essentially the master regulator of a variety of other organs and secretes hormones that have a generalized effect. Here is a complete list of the hormones produced by the pituitary gland and its function:

  • Adrenocorticotropin: incites the production of cortisol.
  • Thyroid-stimulating hormone: stimulates the secretion of thyroid hormone.
  • Antidiuretic hormone: vasopressin regulates the retention of water by the kidneys.
  • Oxytocin: triggers labor, uterine contractions, and milk ejection in the nipple.
  • Follicle-stimulating hormone: promotes the production of sperm and activates ovulation.
  • Prolactin stimulates breast milk production and affects the levels of sex hormones in the ovaries and testes.
  • Luteinizing hormone: activates the production of testosterone and estrogen.
  • Growth hormone: stimulates growth, maintains a healthy muscle and bone mass, and affects the distribution of fat and metabolism.

As you can see, the release of the pituitary hormone plays a vital role in your health and well-being.

Problems with the pituitary gland

The most common cause of pituitary gland problems is tumors, most of which are benign.

Its appearance is quite common, and the problem usually involves:

  • Problems are related to pressure.
  • Too much hormone secretion (hypersecretion).
  • Too little secretion of a hormone (hyposecretion).

As a result, these problems related to the tumor of the pituitary gland can lead to other hormonal imbalances or effects on health; for example, can be one of the causes of these problems:

Large pituitary tumors can pressure the surrounding tissue, causing headaches, vision problems, smell problems, etc.