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:
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.
It is also referred to as the pituitary stalk or infundibulum. It joins the hypophyseal and the hypothalamic systems.
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 1 – Posterior pituitary
Picture 2 – Posterior pituitary Image