Female Reproductive system Ovary Uterus Mammary glands Ovary

Female Reproductive system: Ovary Uterus Mammary glands

Ovary - hormonal regulation - follicular development - Graafian follicle - corpus luteum

Ovary - covered by low cuboidal epithelium (germinal epi. ) - cortex - stroma with fibroblasts - ovarian follicles--> development and atresia

Ovarian follicles - primordial follicle - primary follicle - secondary follicle - Graafian follicle - corpus luteum

Primordial follicle - primary oocyte (prophase or meiosis I) and simple squamous follicular cells

Primary follicle - enlarged oocyte (nucleus up to 150 mm) - simple cuboidal follicular cells --> stratified cuboidal --> granulosa cells / bl Zona pellucida During follicular dev. , gap junctions between follicular cell filopodia and oocyte microvilli. Stroma cells --> theca interna -vascularized, secrete androstenedione --> theca externa (fibrous)

Secondary follicle - FSH stimulates granulasa cell proliferation --> liquor folliculi between granulosa cells --> antrum is space with coalesced liquor folliculi --> corona radiata around oocyte - FSH stimulates expression of LH receptors on granulosa cells

Graafian follicle: - can see on slide with unaided eye - cumulus oophorus: oocyte +corona radiata + attached follicular cells LH surge --> increased blood flow to ovaries --> edema (leaking plasma) in theca externa also: completion of meiosis I and then meiosis II --> ovulation of secondary oocyte and few follicle cells

Corpus luteum: Continued high LH Collapse of remaining Graafian follicle --> granulosa lutein cells produce progesterone & convert androgens to estrogen --> theca interna---> theca lutein cells produce progesterone, androgens & estrogen produce progesterone & convert androgens to estrogen

High levels of progesterone & estrogen --> LH and FSH secretion inhibited --> lower FSH prevents follicular dev. If pregnancy occurs, placenta secretes human choriogonic hormone (HCG), which maintains the corpus luteum.

Atretic follicles: - most follicles degenerate before maturing -