Follicular Dynamics its Regulation and Heat Stress Effects on Folliculogenesis: A Review

Follicular dynamics is a continuous process of growth and regression of a group of antral follicles, one of which develops to attain pre-ovulatory stage. Follicles are formed when primary oocytes are enveloped by a single layer of flattened granulose cells during pre-natal period. Hence, the primordial follicle is a simple structure consisting of primordial oocytes surrounded by a single layer of flattened granulose cells demarcated from the stroma by the non-cellular basal lamina. This primordial follicle reserve formed during fetal life or soon after birth remains in the resting stage until they are stimulated. Follicular growth pattern proceeds through integrated stages of follicular recruitment, selection and dominances. A group of primordial follicles are recruited periodically to grow and pass through a phase of growth till either ovulate or degenerate. Follicular growth is believed to commence in a centrifugal pattern within the ovary.