The Pituitary Gland
The pituitary gland is a small gray structure located at the base of the brain above the sphenoid bone. It is connected to the hypothalamus by the unfundibular stalk. The pituitary gland is responsible for the function of many other glands. It is considered to be the "master" gland, however the hypothalamus is another "master" gland, as well. In addition, the pituitary gland is regulated by the hypothalamus. Another name for the pituitary gland is the hypophysis (Timby & Smith, 2013). The pituitary gland is divided into three parts: the anterior lobe (adenohypophysis), intermediate lobe (pars intermedia), and the posterior lobe (neurohypophysis). The anterior lobe makes up 80% and the posterior makes up 20% of gland.
The Anterior Pituitary gland produces the following hormones:
•GH
– Growth hormone also called somatotropic hormone
– stimulates the growth of bones, muscles, and other organs
•ACTH
– Adrenocorticotropic hormone
– stimulates secretion of adrenal cortex hormones
– controls growth, development, and function of the adrenal cortex
•TSH
– Thyroid stimulating hormone
– Stimulates thyroid to produce thyroid hormones, T4 & T3…TSH is needed for production of T4 and T3 in metabolism…so, controls the secreting activity of the thyroid
•FSH
– Follicle stimulating hormone
– stimulates development of ovum (eggs) in the ovaries and sperm in the testicles
•LH
– Luteinizing hormone in females and interstitial cell-stimulating hormone (ICSH) in males
– initiates ovulation in the woman and secretion of sex hormones in both sexes
•Prolactin
– Lactogenic hormone
– stimulates production of beast milk in the woman but has no known function in the man.
The posterior pituitary gland which is an extension of the hypothalamus and is located behind the anterior pituitary secretes the following hormones:
•Antidiuretic hormone (ADH)
– also called vasopressin
– stimulates retention of water by the kidneys. Also controls excretion of water by the kidneys by affecting the reabsorption of water from the kidney tubules.
•Oxytocin
– causes the uterus to contract at term and stimulates release of breast milk into the breast ducts