Corpus Luteum - Anatomy & Physiology

()Map REPRODUCTIVE SYSTEM (Map) FEMALE REPRODUCTIVE TRACT THE OVARY

• When the dominant antral follicle ovulates, slight localised haemorrhage occurs at the site of ovulation and fills the former cavity.
• The small amount of bloody tissue can be observed by the naked eye.
• Loss of fluid from the antral cavity causes the follicle to collapse into many folds.
• As a result, some granulosal and thecal layers are pushed into the apex of the ruptured follicle.
• This protrusion of tissue and ruptured blood vessels forms a structure known as the Corpus Haemorrhagicum.
• Following this, the theca interna and granulosa cells differentiate into large and small luteal cells.
• As the blood is resorbed, a solid Corpus Luteum is formed by proliferation of granulosa and theca intera cells as well as blood vessels. This remains on the surface of the ovary.
• In the non-pregnant animal, corpora lutea are transient structures.
• Cyclic corpora lutea undergo proliferation and vascularisation directly after ovulation.
• The corpora lutea then regress and degenerate into a connective tissue scar, the Corpus Albicans.
• If the ovum is fertilised, the corpus luteum remains fully developed and active throughout at least part of the pregnancy.
• Corpora lutea produce progesterone.
• Progesterone prepares and maintains the uterus for implantation of the fertilised ovum.