Question

A cleft occurs in hypophysis between
A) Median eminence and stalk
B) Hypophyseal stalk and pars nervosa
C) Pars tuberalis and pars distalis
D) Pars distalis and pars intermedia

Answer 1

Hint: Hypophysis are the ductless glands of the endocrine system. It is also known as pituitary gland. It is located at the base of the brain.

Complete answer:
The pituitary gland is composed of three lobes depending on the position of ectodermal Rathke’s pouch.
Anterior lobe- When the Rathke’s pouch develops upward, it is called adenohypophysis. It is divided into three sections –Par distalis is the largest section, Par tuberalis which is a collar tissue that surrounds stalk, Pars intermedia is a narrow band which is separated from par distalis by a cleft.
 Intermediate lobe- It is non vascular in nature and is absent in humans. It is present in rodents like mice, rats.
Posterior lobe- this lobe is formed when Rathke’s pouch develops ventrally. It is also called neurohypophysis. It has three sections Pars nervosa as the bulk, upper section above pars tuberalis called the Median eminence and the stalk that connects pars nervosa to the base of the brain.

 Thus the correct answer is (D) Hypophyseal cleft separates Par dist.

Note:Pituitary gland or hypophysis is the main endocrine gland. It plays a major role in regulating body functions. Out of the three lobes, the intermediate lobe is absent in human beings.