a-short-review-of-histology

Corpus Luteum:

After release of the oocyte and its surrounding follicular cells and antral fluid at ovulation the remaining parts of the ovarian follicle give rise to the corpus luteum
The membrana granulosa (follicular cells) and the cells of the vascularised theca interna differentiate into the hormone producing cells of the corpus luteum
The cells of the theca externa remain as a surrounding capsular layer of connective tissue stromal cells
There is extensive vascularisation of the developing corpus luteum as is typical of an endocrine gland anywhere in the body
The corpus luteum produces the hormones of pregnancy - progesterone and oestrogen
A functional corpus luteum is formed whether or not the oocyte released during that cycle is fertilised
However, the corpus luteum will only survive beyond 7-10 days if pregnancy occurs and the early placenta produces a hormone called human chorionic gonadotrophin (hCG)
In the absence of hCG the corpus luteum does not survive and its breakdown triggers the start of another cycle

Micrograph of Corpus Luteum:

The large pale staining cells (arrows) are the hormone producing cells of the corpus luteum
The small densely stained cells are mostly endothelial cells of the numerous blood capillaries that deliver nutrients to the hormone producing cells and also carry the hormone to the target structures