Tones of Pictures, Most Commons and Mnemonics

Saturday, August 11, 2007

Theca and Granulosa cells

LH stimulate Theca cells to produce androstendione, which inturn is given to Granulosa cells
FSH stimulate Granulosa cells conversion of androstendione to estradiol by aromatase

Theca cells-->Theca lutein cells---------->Progesterone, Androgens

Granulosa cells-->Granulosa lutein cells------ >Progesteron, Estrogen
The corpus luteum is formed by both granulosa cells and thecal cells after ovulation has occurred. The wall of the follicle collapses into a folded structure, which is characteristic for the corpus luteum. Vascularization increases and a connective tissue network is formed. Theca interna cells and granulosa cells triple in size and start accumulating lutein (Which hormone stimulates this process? Where is this hormone produced?) within a few hours after ovulation. They are now called granulosa lutein cells and theca lutein cells and produce progesterone and oestrogens.
Hormone secretion in the corpus luteum ceases within 14 days after ovulation if the oocyte is not fertilised. In this case, the corpus luteum degenerates into a corpus albicans - whitish scar tissue within the ovaries.
Three major types of ovarian neoplasms are described, with epithelial cell tumors (70%) comprising the largest group of tumors. Germ cell tumors occur less frequently (20%), while sex cord–stromal tumors make up the smallest proportion, accounting for approximately 8% of all ovarian neoplasms.
Granulosa-theca cell tumors, more commonly known as granulosa cell tumors (GCTs), belong to the sex cord–stromal group and include tumors made up of granulosa cells, theca cells, and fibroblasts in varying degrees and combinations. GCTs account for approximately 2% of all ovarian tumors and can be divided into adult (95%) and juvenile (5%) types based on histologic findings.
Both subtypes commonly produce estrogen, and estrogen production often is the reason for early diagnosis.

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