Endocrine System > Hypothalamus and Pituitary

Anatomy and Histology of the Pituitary

The pituitary gland or hypophysis is derived from two embryologically-distinct tissues. As such, it is composed of both neural and glandular tissue. Both tissues produce hormones that affect a large number of physiological processes.

Prior to embarking on the lessons below, it would be best to review the core section Functional Anatomy of the Hypothalamus and Pituitary Gland.

Summary of Lesson
Close examination of a sectioned pituitary gland reveals two closely apposed, but distinctive tissues called the adenohypophysis (anterior or glandular pituitary) and neurohypophysis (posterior or neural pituitary). The adenohypophysis is further classified into several regions. The adenohypophysis and neurohypophysis have seperate embryological origins.
Microscopic examination of the conventionally-stained adenohypophysis reveals three distinctive cell types called acidophils, basophils and chromophobes. This pattern of staining reflects the chemical character of intracellular hormone-laden granules within the pituitary cells.
The neurohypophysis is an extension of the hypothalamus. It composed of bundles of axons from hypothalamic neurosecretory neurons intermixed with glial cells.

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