This is a large and compact structure having abundant vasculature. It is also sometimes called pars buccalis. The adenohypohysis consists of the following three parts.
1. Pars distalis:
This is the largest part of the adenohypophysis constituting about 75% of the pituitary. Here the cells are arranged in cords and in between the cords are found capillaries.
2. Pars tuberalis:
This is smaller than pars distalis. The cells here are polyhyderal in shape with a centrally located nucleus. The cytoplasm is full of fine granules. The cells are arranged in clusters or threads. Pars tuberalis is rarely found in man.
3. Pars intermedia:
This part of the adenohypophysis is poorly developed in human beings.