Synonyms
Greek: Pituitary gland Latin: Glandula pituitaria
Anatomy of the pituitary gland
The pituitary gland is about the size of a pea and lies in the middle cranial fossa in a bony bulge, the sella turcica (Turkish saddle, due to a shape reminiscent of a saddle). It belongs to the diencephalon and lies in close proximity to the optic nerve junction. It is separated only by the bony base of the skull from the nasopharynx and the sphenoid sinus, a paranasal sinus.
The pituitary gland is connected to the hypothalamus above it via the pituitary stalk (infundibulum). The pituitary gland is anatomically divided into two parts: the anterior pituitary gland (adenohypophysis) and the posterior pituitary gland (neurohypophysis). These two parts developed from different parts. While the anterior pituitary produces its own hormones, the posterior pituitary only releases the hormones produced by the hypothalamus, to which it is connected via small blood vessels.
Function
The pituitary gland is a hormonal gland that belongs to the endocrine system. It has a superior control function in the hormone balance. The regulation of the human hormone balance is very complex and comprises three levels of control: the hypothalamus is the highest regulatory unit.
The hypothalamus releases liberine and inhibins, control hormones that in turn cause the pituitary gland to release hormones. The pituitary gland can be described as the second highest regulatory unit. It in turn releases stimulating hormones, the tropins, which act on the body’s hormone glands.
These glands, such as the thyroid gland, testes, ovary and adrenal cortex, are the third institution to secrete free hormones. These free hormones directly influence the body, water, sexual and energy balance. The following hormones are produced in the front lobe of the pituitary gland: TSH (thyrotropin), LH (luteinizing hormone), FSH (follicle stimulating hormone), STH (somatotropin, also GH for Growth Hormone), ACTH (coticotropin), MSH (melanotropin) and prolactin.
The TSH formed in the pituitary gland is the thyroid stimulating hormone. It stimulates its growth and promotes the secretion of thyroid hormones from the thyroid gland. LH and FSH are important sexual hormones in both men and women.
LH triggers ovulation in women, promotes growth and formation of the corpus luteum, which is important for pregnancy. In men, LH promotes testosterone production in the testicles. In women, FSH promotes the maturation of the egg cells in the ovary, in men, the maturation of the sperm cells.
GH or STH is important for the growth of all organs as well as the growth of the trunk and the arms and legs. It is released in childhood during growth spurts, but is also a necessary growth hormone in adults. ACTH stimulates the adrenal cortex, which in response to this stimulus mainly produces cortisone.
This is a stress hormone which is important for raising blood sugar levels, suppressing excessive inflammatory reactions, protein metabolism and much more. The MSH of the pituitary gland stimulates the pigment cells (melanocytes) of the skin to form color pigments. Prolactin is the hormone that stimulates the mammary gland of a pregnant or nursing woman to grow and produce milk.
The following hormones are produced in the posterior pituitary gland: Oxytocin and ADH (antidiuretic hormone or adiuretin or vasopressin). Oxytocin is a hormone with many functions. It is also known as the “cuddling hormone” because it is secreted upon physical contact.
It is also important for the development of contractions during birth. Finally, it is secreted during breastfeeding and leads to milk secretion in the direction of the nipple. ADH is a hormone that is involved in the regulation of the water balance. It promotes the reabsorption of free water in the kidneys so that less water is excreted with the urine and consequently blood pressure rises.
