Question

Draw a neat labelled diagram of Graffian follicle.

Answer 1

Hint: The human ovary consists of an inner medulla and an outer cortex with an indistinct boundary. The medulla contains blood vessels and nerves, while the cortex is used to develop follicles.

Complete answer:
A spherical, fluid-filled vesicle in the ovaries of a mammal containing an oocyte attached to its wall and responsible for developing oestrogen in the ovaries.. The first cavity appears between the follicle cells surrounding the oocyte, around the end of the cytoplasmic growth of the oocyte.

In mammals with an estrous cycle, it widens during the early part of the cycle so that the follicle cells separate into two layers, one around the oocyte and the other the outer layer, until the follicle bursts to the surface of the ovary, discharging the oocyte (ovulation).

The Graafian follicle is the follicular stage after the first meiotic division but before the ovulation phase. Therefore, it contains a 2N haploid oocyte. It is characterized by a large follicular antrum that makes up most of the follicles. The secondary oocyte is placed eccentrically, having undergone the first meiotic division.

It is surrounded by a zone of pellucide and a layer of several cells known as corona radiata. When released from the Graafian follicle and into the oviduct, the ovum contains three layers: oocyte, zona pellucida and corona radiata.

Note: However, most follicles will not ovulate but will simply degenerate; the rest of the follicles will form the corpus luteum in most mammals. The growth of the follicle is influenced by the pituitary gland.