Rathke's pouch

Overview
In embryogenesis, Rathke's pouch is a depression in the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary, a part of the endocrine system.

Development
The pouch eventually loses its connection with the pharynx giving rise to the anterior pituitary. The anterior wall of Rathke's pouch proliferates, filling most of the pouch to form pars distalis and pars tuberalis. The posterior wall forms pars intermedia.

In some organisms (humans being a notable exception), the proliferating anterior wall does not fully occupy Rathke's pouch, leaving a remnant (Rathke's cleft) between the pars distalis and pars intermedia.

Clinical significance
Rathke's pouch may also persist as cysts (craniopharyngioma) within the pars intermedia.

Eponym
It is named for Martin Rathke.