Female Reproductive system

一 Components 1 ovary: -produce ovum -secrete female sex hormone 2 oviduct: -convey ovum & zygote -place where fertilization occur. 3 uterus: organ where fetus grow up 4 vagina: birth canal 5 external genitals: Female generative organs undergo changes with woman ages. Female generative organs undergo changes with woman ages.

二 Ovary ---ovoid, 4cm long, 2cm wide, 1cm thick ---located on either side of uterus in pelvic cavity

一 ) General structure ---capsule: /germinal epi. simple squamous/cuboidal epi. /tunica albuginea: DCT ---cortex: periphery thick /different stage of follicles & corpus luteum /stroma: DCT, rich in RF & spindle-shaped stroma cells ---medulla: central thin, LCT with BV, LV hilum: SM hilum cell(secrete androgen) There are no sharp limits between cortex and medulla.

二 ) Development and maturation of follicle -follicle = 1 oocyte + follicular cells -from puberty, undergo 4 phases: Primordial follicle Primordial follicle Primary follicle Primary follicle Secondary follicle Secondary follicle Mature follicle Mature follicle

1 Primordial follicle: million (before puberty) small in size. in superficial layer of cortex -consists of a primary oocyte surrounded by a layer of squamous follicular cells. -primary oocyte: round, D=30-40um, w/ a large, pale-stained spherical nucleus & a prominent nucleolus.

2. Primary follicle:  From beginning of puberty Due to stimulation of FSH (follicle-stimulating hormone) Primordial follicle Primary follicle  l5-20 primordial follicles develop within each menstrual cycle. Only one of them reaches full maturity & gets to ovulation, the others degenerate.

The main changes are: a Primary oocyte: grow up, rich in RER,ribosome,lysosome b Follicular cells: squamous cuboidal simple layer several layers c Zona pellucida appears LM: -homogeneous,eosinophilic layer b/w oocyte & follicle cells; -produced by both oocyte & follicular cell.

EM: -both Mv. of oocyte & processes of follicular cells extend into Zona pellucida -some Mv communicate w/ processes -gap junctions are seen b/w folliclular cells & b/w oocyte & follicular cells. 初级卵母细胞和卵泡细胞超微结构模式图

3 secondary follicle: small space appear between follicular cells a Primary oocyte: continue to develop, reach largest D ( um) b Follicular cell: more layers(6-12) c Follicular antrum: small space between follicular cells fuse and form a large cavity. filled with follicular fluid (secreted by follicular cells & permeated from BV)

d cumulus oophorus: follicular fluid increase to force the oocyte and some follicular cells move to one side to form a hillock-liked structure. e corona radiata: a layer of follicular cells around oocyte arranged radiately. f granulosa layer several layer of follicular cell around antrum,form follicular wall g theca folliculi: derived form surrounding stroma cells -theca interna: rich in Cap.and cells (theca cell) polygonal.steroid-hormone secreting cell( SER,Mit., lipid droplet) corperate with granulosa cells to secrete estrogen - theca externa: rich in fibers, less cells and Cap.

颗粒层 granulosa layer 颗粒层 cumulus oophorus 卵丘 Follicular antrum 卵泡腔 卵泡膜 theca folliculi Zona pellucida 透明带

4. Mature follicle - the follicle reaches largest D(2cm) & bulges onto the surface of ovary; -follicular fluid increase; follicular antrum enlarge & granulosa layer become thinner; the whole process of growth from primordial to mature follicle lasts 90 days.

Before birth, oogonia come from yolk sac, enter ovarian cortex, develop into primary oocyte, then primary oocyte begin the first meiosis and rest at prophase. Before ovulation, the first meiosis is completed, primary oocyte divides into a secondary oocyte and a first polar body (will disappear), then the secondary oocyte begin the second meiosis and rest at metaphase. It is ready to ovulation.

三 )Ovulation ---definition: the process by which secondary oocyte, zona pellucida, corona radiata and follicular fluid are released into the pelvic cavity, then captured by oviduct fimbriated funnel ---time: 14th day of a menstruation ---process: follicle projects from surface of ovaries→the area lack of blood →follicular stigma→tissue is dissolved by proteinase and collegenase, SM contract→follicle rupture→ the cumulus oophorus go out of the follicle

---fate of the ovum -After ovulation, ovum maintain capacity for fertilization for 24 hours -if fertilized, secondary oocyte completes the second meiosis & forms a mature ovum ， nuclear type (23, X). -if not fertilized, the ovum will degenerate.

四 ) formation of corpus luteum ---definition: after ovulation, the follicle wall remaining in ovary collapse, CT and blood vessel enter the follicle, the cells of follicle wall differentiate to form a yellow- colored, gland-liked structure.

---components and functions: granulosa lutein cell: -come from granulosa cell -LM: numerous, large, polygonal pale-stained, centrally located -EM: steroid-hormone secreting cell -function: secrete progesterone theca lutein cell: -come from theca interna -LM: less,small, deep-stained, peripherally located -EM: steroid-hormone secreting cell -function: secrete oestrogen

---development: corpus luteum of menstruation: -if the ovum is not fertilized -exist for 14 days, then become corpus albicans(DCT) corpus luteum of pregnance: -if fertilized -exist for 6 months, then become corpus albicans

五 ) atretic follicle and interstitial gland ---atretic follicle: Follicles will degenerate at any stages ---interstitial gland: during degenerating process of secondary follicle, cells of theca interna persist active to form a gland, and produce

三 Uterus --- a pear-shaped muscular organ with a thick wall. --- includes 3 parts: fundus 、 body 、 cervix. Fundus of uterus Body of uterus cervix

-relatively thick -divided into 3 layers: endometrium myometrium perimetrium 1 perimetrium serosa(most area), fibrosa(cervix) 一） the structure of uterine wall

2 myometrium: muscullosa thickest tunica (l2-15 mm) ---bundles of SMF: increase in number (hyperplasia) and size (hypertrophy, 50um to 500um) during pregnancy. after pregnancy, uterus is reduced in size to prepregnancy dimensions. ---CT: rich in BV

3 endometrium: mucosa ---simple columnar epi. & ciliated cell & secretory cell ---lamina propria(stroma) thick CT contain BV,stroma cells & uterine gland ( chiefly secretory cells w/ a few ciliated cells) contain BV,stroma cells & uterine gland (single tubular gland,chiefly secretory cells w/ a few ciliated cells)

---two layers: according to the function -basal layer: deep,thin,not shed, proliferate and repair mucosa. -functional layer: superficial,thick, shed(cyclic change-menstrual cycle) Functional layer Basal layer

二 )cyclic change of endometrium ---menstrual cycle from puberty, functional layer sheds & bleeds in cycle, & then regenerates from the basal layer. ---definition: from puberty, under the regulation of ovarian hormones, functional layer of endometrium sheds & bleeds in cycle, & then regenerates from the basal layer. ---average duration of a cycle is 28 days. Begin from the day when menstrual bleeding appear ---3 typical phases can be distinguished Menstrual phase(1-4D) Proliferative phase(5-14D) Proliferative phase(5-14D) Secretory phase(15-28D) Secretory phase(15-28D)

1. Proliferative phase (5-14d) (follicular phase). A group of follicles are developing & secreting estrogen in ovary. estrogen stimulates endometrium to proliferate and repair. 1)Epi. Cell: proliferate & repair 2)stroma cell: proliferate & synthesize stroma & fibers 3)uterine gland: grow up & storing glycogen. straight tubule with narrow lumen. 4) spiral A: become longer,stretch to functional layer. 5) thickness of endometrium: 2-3mm Around 14th day, a follicle mature and ovulate, endometrium enter the secretory phase

Proliferative phase

2. Secretory phase (15-28d) ( luteal phase) After ovulation, corpus luteum secrete progesterone & estrogen which make endometrium enter the secretory phase 1)endometrium: thickest, 5mm 2)stroma cell: full of glycogen & lipid droplet 3)gland: highly coiled, gland cell begin to secrete glycogen, glandular lumen enlarge & full of secretion; 4)spiral A: further stretch & coil. If fertilization occur, endometrium thicken to become decidua. If no fertilization occur, corpus luteum degenerates & level of progesterone & estrogen decrease, next menstrual phase begin at the 28th day.

3 Menstrual phase (l-4d) If no fertilization occur, corpus luteum degenerates & level of progesterone & estrogen decrease sharply. 1) vasoconstriction of spiral A intensely & continuously result in ischemia & necrosis of BV wall & functional layer 2) vasodilation of spiral A subsequently result in bleeding & shedding of the necrotic tissue. At the end of menstrual phase, the whole functional layer shed.