Posterior pituitary

The neurohypophysis (Latin: neuro hypophysis ) - sometimes referred to as lax posterior pituitary ( HHL) - is part of the pituitary gland ( hypophysis). Hormones produced by the hypothalamus are transported to the posterior lobe of the posterior pituitary and released here in the bloodstream. In contrast to the adenohypophysis, it is evolutionarily a part of the brain. The term posterior pituitary used in human anatomy refers to the topographical situation in humans, since the neurohypophysis forms the posterior portion of the pituitary gland here. Comparing - anatomically it is simply not true, as the neurohypophysis is completely enclosed in some mammals (such as predators, horses ) from the anterior pituitary.

Hormones

In the neurohypophysis two hormones in the blood are submitted:

• Antidiuretic hormone ( ADH; Synonyms: Adiuretin, vasopressin ) regulates water reabsorption in the kidneys; the urine becomes more concentrated ( at the same time increases the blood pressure)
• Oxytocin causes contraction of smooth muscles, especially of the uterus during childbirth ( Ferguson reflex), and it stimulates the mammary gland of the dairy payout to.

Anatomy

The neurohypophysis is composed of two parts:

• Of the pituitary stalk ( the infundibulum ) connects the pituitary gland to the rest of the brain.
• The posterior lobe ( pars nervosa ) is the rearmost part of the pituitary gland.

The neurohypophysis is above the optic tract hypothalamohypophysialis with the hypothalamus in conjunction. In the supraoptic nucleus formed ADH and formed in the paraventricular nucleus oxytocin bind to neurophysins by axons of this tract transported from the hypothalamus to the pituitary gland where it is stored. If necessary, the hormones are proteolytically cleaved from their neurophysin and released into the bloodstream. The neurohypophysis is thus a Neurohämalorgan.