physiology of reproduction 2

premordial follicle

primary oocytes arrested in prophase 1

surrounded by single layer of pre granulosac ells

describe follicular growth

premordial follicle

FSH stimulate increased growth so inc E2 production ththat timulates formation of more FSH receptors more follicular growth

preantral follicle

a hyaline membrane now is formed around oocyte and limits further inc in size (zona pelucida)

pre granulosa cells cuboidal and proliferate layers of granulose cells (membrane granulose )

fluid spaces start to appear between the granulose cells (liqour follucli)

surrounding parenchymal cells (theca interna)

follicular selection

of preantral follicle

this high E2 (and inhibin) inhibit FSH so decrease aromatization and increase local androgen so atresia of most follicles

antral (dominant) follicle

is immune aganist atresia as it has large number of FSH receptors

fluid spaces between granulosa cells join together to form large antrum full of estrogen

mid cyclic surge

after antral follicle formation

presistant high E2 >50 stimulate positive feedback

cause LH surge

cause FSH smaller surge (2nd surge)

lh surge effect

ensure complete atresia of non dominant follicles

increase libido at mid cycle

ovulation within 36 hours

preovulatory follicle

oocyte resumes the misosis and release 1ry oocyte and 1st polar body

layers of mature graffian follicle

Theca externa

Theca interna

Membrana granulosa

antrum follicle

cumulus oophorus

Corona radiata

Zona pellucida

Perivitelline space

Oocyte

why is LH surge short lived

exhaustion of LH storage in the pitutary

loss of positive feedback stimulus of E2

corpus luteum formation

proliferative stage : granulosa and theca cells multiply rapidly

luteinization stage :deposition of cholesterol (become yellow)

granulosa cells become lutein cells

theca cells become paralutein cells

fate of corpus leutem

if no preg :regression

if preg : fetal trophoblst release HCG stimulation of more growth of CL and inc E2 and prog till 12 weeks

two cell theory

theca cells : cholesterol,progesterone,androgen

granulosa cells :estrogen

cels in secretory phase

early:subnucler intracytoplasmic granules released in endometrium

mid: 7 days after LH surge peak secretory activity layge granulated lymphocytes regulate trophoblast invasion

late :(decidua)stratum basalis ,spongiosum and compactum

progesterone effect on e2

inhibit increase in thickness

composition of menstrual flow

mainly blood 75% arterial and 25% venous

FDPs

endometrial shreds

cervical mucus

uses of estrogen and progesterone

contraception

in menstrual disturbances

menopause

infirtility

abortion

local effect of estrogen and progesterone on myometrium

estrogen inc contractility

progesterone relax myometrium

action of LH

stimulate steroidogenisis in granulosa cells

stimulate spermatogenisis in males

action of lH

stimulate steroidogenisis in theca cells

stimulate steroidogenisi in males by lidig cells

action of HCG

maintain corpus luteum in preg till placental steroidogenisis at 12 w

important for steroidogenisis in male fetus

uses of gonadotrophins FSH

FSH/LH :in hypothalamic/pitutary failer clomiphene induction failer

HCG: ovulation triggering

level of progesterol and FSH and LH and prolactin and estrogen

progesterone :>10ng

FSH : 5-30ng

LH : 5-20ng

prolactin 2-20ng

estrogen : 30-75 picogram