Webster's New World Medical Dictionary

pit, ear
See 
ear pit.
pit, preauricular
See 
ear pit.
pituitary 1
Pertaining to the pituitary gland or its
hormonal secretions.
2
The pituitary gland.
pituitary, anterior
The front portion of the pitu-
itary gland. Hormones secreted by the anterior pitu-
itary influence growth, sexual development, skin
pigmentation, thyroid function, and adrenocortical
function. These influences are exerted through the
effects of pituitary hormones on other endocrine
glands, except in the case of growth hormone,
which acts directly on cells. The effects of under-
function of the anterior pituitary include dwarfism
in childhood and disruption of the other endocrine
gland functions that are normally under the control
of the anterior pituitary. The results of overfunction
of the anterior pituitary include gigantism in
children and acromegaly in adults. See also
acromegaly; dwarfism, pituitary; gigantism,
pituitary. 
Also known as adenohypophysis.
pituitary, posterior
The back portion of the
pituitary gland. The posterior pituitary secretes the
hormone oxytocin, which increases uterine con-
tractions and antidiuretic hormone (ADH), which
increases reabsorption of water by the tubules of the
kidney. Underproduction of ADH results in diabetes
insipidus, which is characterized by inability to con-
centrate the urine and, consequently, excess urina-
tion, leading potentially to dehydration. See also
antidiuretic hormone; diabetes insipidus; oxy-
tocin.
Also known as neurohypophysis.
pituitary adenoma
A benign tumor of the pitu-
itary gland, the master gland that controls other
glands and influences numerous body functions,
including growth. Although a pituitary adenoma
itself is not cancerous, it may affect pituitary func-
tion and therefore may need to be removed. See
also 
pituitary gland; gigantism, pituitary.