Pituitary gland:The mainendocrine gland. It is a small structure in the head. It is called the masterglandbecause it produces hormones that control other glands and many body functions including growth. Thepituitaryconsists of theanteriorandposteriorpituitary.
Theanterior pituitaryis the front portion of the pituitary. Hormones secreted by it influence growth, sexual development, skinpigmentation,thyroidfunction, and adrenocortical function. These influences are exerted through the effects of pituitary hormones on other endocrine glands except forgrowth hormonewhich acts directly on cells.
The effects of underfunction of the anterior pituitary include growth retardation (dwarfism) inchildhoodand a decrease in all other endocrine gland functions normally under the control of the anterior pituitary (except the parathyroid glands). The results of overfunction of the anterior pituitary include overgrowth (gigantism) in children and a condition calledacromegalyin adults.
Theposterior pituitaryis the back portion of the pituitary. It secretes the hormoneoxytocinwhich increases uterine contractions andantidiuretic hormone(ADH) which increases reabsorption of water by the tubules of the kidney. Underproduction of ADH results in a disorder calleddiabetesinsipidus characterized by inability to concentrate the urine and, consequently, excess urination leading potentially to dehydration. The urine is "insipid" (overly dilute).
