A Quantitative Study of the Human Hypophysis Cerebri, or Pituitary Body*

While the general size and appearance of the normal human hypophysis is generally well known, this organ has become of such clinical importance that more accurate data are necessary especially on the limits of normal variability, not only of the organ as a whole but also of the size and histological appearance of its various parts. It may be well to recall that the pituitary body is a complex structure composed of pars anterior (pars distalis), pars nervosa (processus infundibuli or pars posterior), pars intermedia (juxtaneuralis or pars infundibularis) and pars tuberalis (an epithelial extension along the under surface of the tuber cinereum or floor of the third brain ventricle). Most of these are shown in Figure 1, as seen in horizontal section. These various portions apparently differ functionally and must, therefore, be evaluated independently. While there are thousands of weights of the main portion of the gland as a whole, there are no accurate figures on the mass of the various subdivisions.