Corpus Luteum Formation - Anatomy & Physiology
Introduction
Luteinisation occurs after ovulation and the collapse of the follicle. The number of corpora lutea formed in the ovary at any one time is directly proportional to the number of oocytes ovulated. Therefore many corpora lutea will be visible on the ovary of polytocous animals. During Luteinisation there is an increase in both the size and weight due to hyperplasia (increase in cell number) and hypertrophy (increase in cell size) within the developing corpus luteum.
Process of Luteinisation
Tissue Remodelling
- PGE2 released locally within the ovary causes activation of the body's tissue remodelling enzyme plasmin from its zymogen plasminogen. Activated Plasmin dissolves clot of the corpus Haemorrhagicum, formed due to disruption of follicular blood vessels at ovulation. Plasmin also helps in the remodelling of follicular basement membrane into copus luteum connective tissue.
- There is an increase in the pigment lutein within the leteal cells.
- There is development of smooth endoplasmic reticulum within luteal cells due to the increase in steroid production.
Angiogenesis Corpora Lutea require a large blood supply to provide adequate cholosterol for Progesterone synthesis.
Luteinisation Control
Control of corpus luteum formation and development as well as the production of Progesterone by luteal cells is regulated principally by Luteinising Hormone.