Dr. Louis Toth – Fall 2006ljtoth@bu.edu

This is being Reproduced for the benefits of Student.

Our sincere thanks and warm regards to the Author of this article,

Prof. M.C.Bansal. prof Veena Acharya.

Female Reproductive Anatomy

labia majora

labia minora

glans clitoris

corpus cavernosaof clitoris

ovary

oviduct

uterus

vagina

cervix

at menopauseyoung

pituitary gland

uterus/cervix

ovaries vagina

Organs of the female reproductive system

FSHprolactin

GnRH

oxytocin

LH

progesterone

estrogens

hCG, estrogens, progesterone, etc.

oviducts

1. Oogenesis - production of oocytes

2. Steroidogenesis - hormone production

estrogens - estrone (E1), estradiol (E2), estriol (E3) - growth/maturation of sex organs - female secondary sex characteristics - literally “estrus-generating”

progesterone - prepares uterus for implantation - prepares mammary glands for lactation - literally a “promoter of gestation” (progestegen)

progesterone

estrogens

estrone

testosterone Estradiol

cholesterol

(DHEA)

estriol

progesterone

Floyd Landis (Phonak - iShares) - 2006 Tour de France winner? Photo copyright Fotoreporter Sirotti.

tunica albuginiaof ovary

“germinal” epithelium(mesothelium of peritoneum)

medulla

cortex

Hilum - vessels and nerves enter- connective tissue support

Ovary at birth Active ovary

www.udel.edu

Primordial follicle

Primary follicle

Secondary follicle

Graafian (tertiary) follicle

Corpus luteum

Corpus albicans

Atretic follicle

Primary oocyte

Secondary oocyte

Secondary oocyte

Ovum

Zygote

• 6 weeks: primordial germ cells form and migrate to the genital ridge --> induce development of the ovaries

• 6 weeks - 5 months: mitosis --> 6 million oocytes

• 5 - 7 months: meiosis --> arrested at prophase I; oocytes become surrounded by follicle cells

• primary oocytes• primordial follicles

• birth: 1 million primordial follicles remain

• birth: 1 million primordial follicles

• puberty: 400,000 primordial follicles remain

• age ~12-52: 15-20 follicles start to mature each month; typically only one makes it to ovulation 20 foll *12months*40yrs = 9600

• menopause: no viable follicles remain

• Primary oocyte remains arrested at prophase I as the follicle develops

• Just before ovulation, meiosis I is completed

• One cell gets most of the cytoplasm -> secondary oocyte

• The other cell is the first polar body

Human embryo. Arrow = polar body

primary oocyte arrested at prophase I

secondary oocyte in mature follicle - arrested at metaphase II

secondary oocyte in oviduct

zygote(proper)

ovulation

sperm entrycompletes meiosis II

completes meiosis I

first polar body

second polar body

pronuclei fuse ovum(proper)

secondary follicle

primary follicles

primordial follicle

mature follicle

corpus luteum corpus albicans

oocyte

follicle cells

oocyte

granulosa cells

• Oocyte enlarges and matures

• Follicle cells become cuboidal = granulosa cells

theca folliculi

zona pellucida

• granulosa cells divide

• oocyte secretes zona pellucida;

• oocyte and granulosa cells remain interconnected by gap junctions

• stromal cells form the theca folliculi

theca externa

theca interna

antrum

• theca folliculi theca interna: steroidogenic; secrete estrogen precursors

theca externa: contains fibroblasts & smooth muscle

• granulosa cells: convert estrogen precursors into estrogens

theca externa

theca interna

antrum

cumulus oophorus+ corona radiata

Follicles which do not reach ovulation degenerate by atresia:

• pyknotic nuclei

• granulosa cells sloughing off into the antrum

Atresia can occur at any stage of follicular development

corona radiata

zona pellucida

• oocyte + corona radiata + zona pellucida are expelled from the follicle

• increased pressure in antrum

• enzymes secreted by granulosa cells break down wall of follicle and ovary

• smooth muscle in theca externa contracts

Normally only one oocyte is ovulated each cycle. When more than one is ovulated, fraternal twins can result.

Polycystic ovary syndrome (PCOS): follicles form but ovulation does not occur

Norman, Wu, Stankiewicz MJA 2004

Ephraim McDowellFirst laparotomy (oophorectomy),

Danville, KY 1809www.pathguy.com

corpus luteum

• After ovulation, the remaining follicle cells form the corpus luteum

• former granulosa cells become granulosa lutein

• former theca interna cells become theca lutein

•granulosa lutein and theca lutein cells cooperate to secrete progesterone and estrogen

theca lutein cells

granulosa lutein cells

If implantation occurs, embryonic hCG maintains the corpus luteum, which in turn maintains the pregnancy

corpus albicans

If implantation does not occur, the absence of hCG causes the corpus luteum to deteriorate, leaving behind a corpus albicans

isthmus

ampulla

fimbriae ofinfundibulum

intramural portion

Chicken oviduct : Thomas Caceci education.vetmed.vt.edu Advanced Fertility Ctr., Chicago

Laparoscopy image

Fimbria (= “fringe”)move to cover site of ovulationsweeps oocyte into oviduct

Infundibulum (= “funnel”)first portion of tubehighly folded epitheliumthin muscularismore ciliated cells

Ampulla (= “bottle, jar”)usual site of fertilization

Isthmus ( = “bridge”)thickest muscularismore peg cells

Intramuraltraverses wall of uterus

Wheater’s 8th ed.

Ciliated cells … …beat towards uterus to propel the oocyte …are more frequent towards fimbriaePeg cells …secrete mucus …are more frequent towards uterus

Ratio of ciliated/peg cells changes and correlates with menstrual cycle

Functions: • provides environment for developing embryo• expels embryo at birth

3 Layers:• endometrium (mucosa of the uterus):

• simple columnar secretory epithelium with simple tubular glands• very well vascularized connective tissue• subdivided into 2 layers: stratum basale + stratum functionalis

• myometrium (muscularis of the uterus): • very thick muscularis organized into three indistinct layers• capable of extreme expansion during pregnancy

• some increase in the number of muscle fibers• great increase in size of existing fibers

• perimetrium (serosa of the uterus):

Functions: - prevents uterine infection - allows sperm to enter uterus

2 parts• endocervix: continuous with endometrium

- simple columnar, mucus-secreting epithelium

- plicae palmatae: crypts

• ectocervix: continuous with vaginal epithelium- stratified squamous non-keratinized

epithelium- screened for cervical cancer by PAP smears

Portio vaginalis – the portion of the cervix that extends into the vaginal canal

The border between endocervix (simple columnar) and ectocervix (stratified squamous) epithelia is located roughly at the external os, and may be more or less extroverted depending on age, parity and other factors

• UK is considering mandatory inoculation for schoolchildren •Australia has subsidized the vaccine, making it available free of charge

Functions: - transport of sperm to uterus - expulsion of newborn - protect against bacterial infections

Histology:• stratified squamous non-keratinized• no glands• thick lamina propria• thin muscularis

• stratified squamous keratinized epithelium• hairless• elastic – stretches during delivery• homologous to male scrotum

Homologousgerm cells -> oogonium, male gametesurogenital sinus -> penile urethra, vestibule of

vaginalabioscrotal folds -> labium, scrotumgenital tubercle -> penis, clitoris

Not homologousMesonephric duct -> Epididymis, vas deferens

≠Paramesonephric duct -> fimbria, oviduct