Neurohipofiz

Neurohipofiz is the posterior lobe of the pituitary gland. It is not a gland that produces hormones itself, but rather stores and releases hormones produced by the hypothalamus. The neurohypophysis is composed of nervous tissue and contains the axons of neurosecretory cells that originate in the supraoptic and paraventricular nuclei of the hypothalamus. These axons terminate in the neurohypophysis, where they release their synthesized hormones into the bloodstream.

The two primary hormones released from the neurohypophysis are antidiuretic hormone (ADH), also known as vasopressin, and oxytocin. ADH plays a crucial role in regulating water balance in the body by increasing water reabsorption in the kidneys, thereby reducing urine production. Oxytocin is primarily involved in social bonding, reproduction, and childbirth. It stimulates uterine contractions during labor and promotes milk ejection during breastfeeding.

The neurohypophysis is connected to the hypothalamus via the hypothalamo-hypophyseal tract. This neural connection allows for the rapid transport of hormones from the hypothalamus to the posterior pituitary for release. The release of ADH and oxytocin is regulated by various physiological stimuli, including changes in blood osmolarity, blood pressure, and sensory input related to social interactions or childbirth. Dysfunction of the neurohypophysis can lead to conditions such as diabetes insipidus (due to ADH deficiency) or problems with lactation and uterine contraction.