Pituitary gland

The pituitary gland is part of the central nervous system.

Function of the pituitary gland

The pituitary gland is an endocrine gland located in the brain, which responds to stimuli from the hypothalamus, producing specific hormones which are released into the blood:

• Adrenocorticotropic hormone (ACTH);
• thyroid stimulating hormone (TSH), which stimulates the secretion of thyroid hormones;
• somatotropin (GH) which stimulates cell growth;
• prolactin (PRL), which stimulates milk production;
• gonadotrophins (sex hormones), lutenising hormone (LH) and follicle-stimulating hormone (FSH);
• endorphins, molecules giving a sense of well-being;
• melanocyte-stimulating hormone (MSH) which stimulates production of melanin.

Structure of the pituitary gland

The pituitary gland is a gland the size of a pea weighing 0.5 grams and connected to the hypothalamus by a stem known as the pituitary gland stalk. The pituitary gland is divided into two lobes:

• The anterior pituitary gland (adenohypophysis) in front;
• the posterior pituitary gland (neurohypophysis) behind.

The posterior pituitary gland is a projection of the hypothalamus which stores and releases ocytocin and vasopressin.

Different cell types produce each of these hormones.