The neurohypophysis forms the posterior lobe of the pituitary. It is also called pars nervosa. It is made up of nervous tissue and terminations of neurosecretory fibres of neuro-secretory cells located in the perotic and paraventricular nuclei of the hypothalamus. It acts as a storage area for the hormones secreted by the neurosecretory cells. These hormones are also called neurohormones.
Neurohypophysis releases 2 types of hormones.
(1) Oxytocin (OT) – Its target organs are the uterus and mammary glands. In the uterus it helps in the contraction of smooth muscles during parturation or child birth. In the mammary glands it acts as a milk letting down hormone (Lactation)
(2) Vasopressin (ADH) – Target organ kidney, specifically the distal convoluted tubules of the nephrons Its function is stimulation of reabsorption of water, during deficit of water in the body.
