a-short-review-of-histology

The Anterior Pituitary:

The anterior pituitary, or adenohypophysis, is the part of the pituitary gland that originates from the epithelium derived from the roof of the mouth
The parenchymal cells produce 7 different hormones (growth hormone, prolactin, adrenocorticotrophic hormone, thyroid stimulating hormone, follicle stimulating hormone, luteinising hormone, melanocyte stimulating hormone)
Cells producing each hormone are located throughout the anterior pituitary
Mostly, each cell only produces one hormone, at least at anyone time
The different cell populations traditionally have been distinguished by using a variety of histological staining techniques, more recently supplemented by electron microscopy examining the detailed morphology of individual cells
However, antibodies directed against the hormones are now the preferred method for examining the frequency and location of individual hormone producing cells
The parenchymal cells are organized into cords which are interspersed with fenestrated capillaries

Anterior Pituitary: Low Magnification

This low magnification mid-sagittal section of pituitary gland shows the anterior pituitary (AP) and the posterior pituitary (PP) including the neural stalk (NS)

Anterior Pituitary: Growth Hormone Producing Cells

This micrograph of anterior pituitary gland shows ‘staining’ with an antibody (labelled with brown marker) raised against growth hormone
The distribution of growth hormone producing cells can easily be seen
Note that they are not all clustered together in one area

Anterior Pituitary: Cords of Parenchymal Cells

These micrographs of anterior pituitary gland show the cords of parenchymal cells and the large diameter capillaries that lie between the cords of cells
Micrograph A is a section stained with haematoxylin and eosin which fails to male a clear distinction between the various secretory cell types found in the anterior pituitary
Micrograph B is one of the special stains historically used to identify subpopulations of cells