Posterior pituitary

Posterior pituitary
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Posterior pituitary Definition

It is a section of the endocrine system that comprises of the posterior lobe of the pituitary gland. It is also known by the name “neurohypophysis.”

Posterior pituitary Location

It is the rear or posterior part of the pituitary gland, a small gland located in the head (also referred to as the master gland).

Posterior pituitary Anatomy

It is mainly a cluster of axons or neuronal projections that extend from the neural structure known as the hypothalamus. It is primarily classified into:

Pars nervosa

This section comprises of the most part of the neurohypophysis. It stores vasopressin and oxytocin. It is sometimes mistakenly equated with Posterior pituitary. It contains the pituicytes and the Herring bodies.

Infundibular stalk

It is also referred to as the pituitary stalk or infundibulum. It joins the hypophyseal and the hypothalamic systems.

Median eminence

It is included as part of the neurohypophysis, although only occasionally.

Posterior pituitary Function

It secretes the hormone known as Oxytocin that increases the level of ADH (antidiuretic hormone) and uterine contractions. It is the antidiuretic hormone that leads to an increase in the reabsorption of water by the kidney tubules. Reduced ADH production leads to Diabetes insipidus characterized by inability to concentrate urine. This consequently results in excess urination, potentially causing dehydration. The neurohypophysis, thus, helps in maintaining urine concentration and balance of water in the body.

Posterior pituitary Problems

The neurohypophysis is associated with disorders like Diabetes insipidus in which the body loses the capability to concentrate urine.

Posterior pituitary Pictures

Check out these images to know how this endocrine structure looks like.

Picture of Posterior pituitary

Picture 1 – Posterior pituitary

Image of Posterior pituitary

Picture 2 – Posterior pituitary Image

References:

http://en.wikipedia.org/wiki/Posterior_pituitary

http://www.medterms.com/script/main/art.asp?articlekey=9709

http://www.lpch.org/DiseaseHealthInfo/HealthLibrary/diabetes/ppdhub.html

Last modified on January 29th, 2013 at 11:02 am

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