Anatomy of the Pituitary Gland

The pituitary gland regulates many hormone systems in the body. It sits at the base of the brain in a bony structure called the sella turcica. The pituitary gland has an anterior (front) and posterior (back) lobe. There are multiple hormones secreted by the pituitary gland, each having a different function. Reproduction, growth and metabolic activities are regulated by the pituitary gland through communication with the hypothalamus and organs in the body. Prolactin, growth hormone (GH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicule stimulating hormone (FSH) and adrenocorticotropic hormone (ACTH) are secreted from the anterior pituitary gland. Vasopressin and oxytocin are secreted from the posterior pituitary gland.


Diagram of the connection between the brain (hypothalamus) and the pituitary gland.



Pituitary tumors can secrete hormones in excess or they may be non-functioning. In addition to physical changes and medical problems, these tumors can cause visual impairment and blindness depending on the location, size and aggressiveness. Growth hormone secreting tumors can result in Acromegaly causing coarsening of facial features, jaw changes, enlarged hands and feet, sweating, joint pain, diabetes, high blood pressure, carpal tunnel syndrome, sleep apnea and gigantism in children. Symptoms of a prolactin secreting tumor in women include breast milk secretion, irregular menstruation, and infertility and in men, impotence and infertility. An ACTH secreting tumor causes Cushing’s disease resulting in diabetes, hypertension, excessive weight gain, facial roundness, bruising, muscle weakness, loss of bone density, and bruising. TSH secreting tumors are extremely rare; however, they may cause symptoms of hyperthyroidism.