Posterior pituitary

The back portion of the pituitary, a small gland in the head called the master gland. The posterior pituitary secretes the hormone oxytocin which increases uterine contractions and antidiuretic hormone (ADH) which increases reabsorption of water by the tubules of the kidney. Underproduction of ADH results in a disorder called diabetes insipidus characterized by inability to concentrate the urine and, consequently, excess urination leading potentially to dehydration. The urine is "insipid" (overly dilute).

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posterior pituitary n

1) NEUROHYPOPHYSIS

2) an extract of the neurohypophysis of domesticated animals for medicinal use called also posterior pituitary extract

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1. neurohypophysis. 2. a powdered preparation of the dried neurohypophysis of certain food animals, having the pharmacological actions of its hormones, oxytocin and vasopressin; used mainly as an antidiuretic in the treatment of central diabetes insipidus, administered subcutaneously, by nasal inhalation, or by topical application to the nasal mucosa. It may be used to stimulate smooth muscle tissue, especially to produce vasoconstriction in the presence of hemorrhage.