Endocrine System – Pituitary Gland By: Marian Liwanen

What is it?  It is a pea sized gland located at the base of the skull between optic nerves.  The pituitary gland is divided into two parts. The anterior lobe and the posterior lobe.  It is also known as the ‘Master Gland’ because it controls the function of other endocrine glands.

Anterior lobe  Makes and secretes six major hormones:  Growth hormone  Thyroid-stimulating hormone  Adrenocorticotropic hormone (ACTH)  Follicle-stimulating hormone and luteinizing hormone (Sex hormones)  Prolactin

Anterior lobe  It also secretes endorphins and chemicals that act on the nervous system to reduce sensitivity to pain.

Posterior lobe  Unlike the anterior lobe, the posterior lobe only produces two hormones.  Antidiuretic hormone which regulates the amount of water released by the kidneys; affects water balance.  Oxytocin which stimulates the contraction of the milk ducts in the breast.

Tumor in the gland  The pituitary gland can evolve a noncancerous tumor.  This leads to overproduction on one or more pituitary hormones.  The tumor may also lead to underproduction of pituitary hormones due to pressure.

Tumor in the gland  Sometimes, one hormone may be overproduced and another under produced at the same time.  This is due to pressure.  Tumor in the pituitary gland can also lead to an enlargement of the gland, without affecting the production of hormones.

Tumor in the gland  Doctors can identify pituitary gland malfunctions by conducting tests.  Imaging tests such as CT and MRI scans can show wether or not a pituitary gland has shrunken or enlarged.