PITUITARY AND PINEAL GLANDS LABORATORY

Slide #51 is a human pituitary stained with hematoxylin and eosin.
Note the following.

  1. Acidophil cells stain bright pink and seem most numerous in the lateral aspects of the gland.
  2. Basophil cells stain light pink-blue, often not real "basophilic" or lavender, and seem most numerous in the central part of the gland.
  3. Chromophobe cells do not demonstrate cytoplasmic staining, and appear as nuclei surrounded by a clear area.
  4. Various combinations of the three cell types may be seen adjacent to each other in small nests set apart by intervening delicate vessels (you can often see the endothelial cells of the vessels even though they may be empty and collapsed.)
  5. The posterior pituitary has a "neural" look, with the cells being essentially indistinguishable from astrocytes.
  6. Within the anterior pituitary, close to the posterior, are small cystic spaces lined by cuboidal epithelium, some of which may demonstrate cilia. These are the remnants of Rathke's pouch.
Slide #88 is a human pituitary stained with PAS-hematoxylin- light green-orange G.
This slide demonstrates cell types more distinctly: the acidophils are green-orange and the basophils purple. The PAS- positive basement membranes of the capillaries are well demonstrated.

Slide #58 is a human pineal gland.
Note that the fibroglial vascular septae produced a pseudoalveolar pattern in this pineal. This is not a constant finding. Among the more numerous pinealocytes with large, vesicular nuclei, try to find the occasional, small, dark nuclei of astrocytes. Calcified deposits are also present. Note also at the base of the pineal gland the roof of the third ventricle which is lined by ependyma and contains choroid plexus.