The Female Reproductive System II

Histology 2016-2017
Department of Anatomy &Histology: Dr.Rajaa Ali
*************************************************************
The Female Reproductive System II
Corpus Luteum:
• The collapsed follicle undergoes reorganization into the corpus luteum after ovulation.
At ovulation, the follicular wall, composed of the remaining granulosa and thecal cells, is thrown into deep folds as the follicle collapses and is transformed into the corpus luteum (yellow body), or luteal gland (janqueira).
• Cells of the granulosa and theca interna layers then differentiate into granulosa luteal and theca luteal cells in the process called luteinization.
• Two types of luteal cells are identified:
• Granulosa lutein cells are large , centrally located cells derived from the granulosa cells.
• Theca lutein cells are smaller , more deeply staining, and peripherally located cells derived from the cells of the theca interna layer (janqueira).
The corpus luteum highly vascularized structure located in the cortex of the ovary secretes progesterone and estrogens. These hormones stimulate the growth and secretory activity of the lining of the uterus, the endometrium, to prepare it for the implantation of the developing zygote in the event that fertilization occurs.
• The corpus luteum of menstruation is formed in the absence of fertilization.
• If fertilization and implantation do not occur, the corpus luteum remains active only for 14 days; in this case it is called the corpus luteum of menstruation.
• The corpus luteum degenerates and undergoes a slow involution after pregnancy or menstruation. The cells become loaded with lipid, decrease in size, and undergo autolysis.
A white scar, the corpus albicans, is formed as intercellular hyaline material accumulates among the degenerating cells of the former corpus luteum (janqueira).