Histology of Female Genital System for Reproductive Module

8/3/2019 Histology of Female Genital System for Reproductive Module

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Histology of theemale Genital Syste

REPRODUCTIVEMODULE


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The female genital system consists of:1. Primary sex organ: 2 ovaries.

2. Accessory sex organs:

1. Two oviducts (Fallopian tubes).2. Uterus.

3. Vagina.

4. External genitalia.

5. Two mammary glands.


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The ovariesThe ovary is a flattenedalmond-shaped small

body, divided intoperipheralcortexandcentralmedulla.

The cortex is broad andcontains the ovarianfollicles separated by theinter-follicular tissue.

The medulla consists ofhighly vascular C.T.,having elastic fibers,smooth muscle fibers,

lymphatics and nerves.


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Stroma of the ovariesTunica albuginea is the covering connective tissue capsule ofthe ovary. It is formed of white collagenous connective tissuefibers.

Stromal cells: are fusiform cells with oval nuclei similar tofibroblasts. They are present between the ovarian follicles.

Reticular connective tissue: present inbetween the ovarianfollicles.

Parenchyma of the ovaries The ovarian follicles: in different stages of development and

degeneration.

The endocrine cells: polygonal in shape, with central roundednuclei. Their cytoplasm is rich in lipoid granules. In animals, theysecrete female hormones, but not in humans.

The germinal epithelium: it covers the ovary from outside. It issimple cuboidal in young females and simple squamous in

adults.


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Histologicalsections in

the ovary


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The ovarian follicles


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The ovarian follicles

They are present mainly in the cortex of the

ovary under the tunica albuginea. They are:1. Primordial follicles.

2. Primary follicles.

3. Secondary follicles.

4. Mature follicles.

At birth, the average number of 1ry follicles is

4000, only 400 ova are produced during thereproductive period of the adult female.

The remaining follicles degenerate and

change to atretic follicles which are convertedto white connective tissue bodies.


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They are derived from the primordial germ cells in theyolk sac and then migrate to the developing ovary.

They are formed ofcentral primary oocytes which aresurrounded by a single layer of simple squamous cellscalled follicular cells.

(1) Primordial follicles(1) Primordial follicles

The oocyte is a largecell with largeeccentric vesicularnucleus with a largenucleolus. Its

cytoplasm contains awell-developed Golgiapparatus, RER,mitochondria and

lipid droplets.


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(2) Primary follicle

The oocyte enlarges anddevelops Golgi apparatus,

ribosomes and mitochondria.It becomes surrounded by athick highly acidophilicglycoprotein coat, called zonapellucida.

The flat follicular cells becomescuboidal and multiply to give riseseveral layers (stratified) calledgranulosa cells.

The connective tissue

surrounding the folliclecondenses and forms twolayers:

Inner highly vascular secretorylayer, theca interna.

Outer fibrous layer, thecaexterna.


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(3) Secondary follicle

The granulosa cells reach 6-12layers and start to secrete fluid

which forms irregular spacesbetween the granulosa cells.

The spaces gradually fuse toform a crescentic space calledantrum which contains liquor

folliculi.The liquor folliculi containsgrowth factors, steroid andgonadotrophic hormones.

The oocyte is eccentric and issurrounded by a mass ofgranulosa cells called cumulusoophorus.

The oocyte starts its 1st meioticdivision and remains in theprophase until ovulation.


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(4) Mature Graafian Follicle

The primordial follicle reachesmaturity in 10-14 days andoccupies the whole thicknessof the cortex and bulges outon the free surface of ovary.

The liquor folliculi accumulates

between the cells of cumulusoophorus freeing the oocytefrom the cells except for onelayer called corona radiatacells.

The granulosa cells secreteestrogen.

The ovum is the largest cell inthe body. It has a large,

rounded eccentric nucleus


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Mature Graafian Follicle


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OvulationIt occurs between day 10-14 of the ovarian cycle.

It is underinfluence of LH of pituitary.

The Graafian follicle rupture through the stigma due to increase ofliquor folliculi.

After ovulation, the oocyte with its surrounding corona radiata entersthe oviduct, complete its first meiotic division and start the secondmeiotic division (which is completed after fertilization).

The remaining

of the mature

follicle is

transformed intocorpus luteum.


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Corpus LuteumCorpus Luteum

It is considered as a temporary endocrine organ.

Basement membrane between theca interna and granulosa

cells dissolves, and capillaries grow in-between granulosacells.

After ovulation, granulosa cells enlarge and accumulate lipiddroplets and called granulosa lutein cells.

Under influence of LH, the granulosa cell secrete progesteroneand estrogen.

The same also happens to theca interna cells which are nowcalled theca lutein cells.

Fate of Corpus LuteumIf pregnancy occurs, it enlarges and continues to function for3 moths till the placenta is formed and take the gob.

If pregnancy does not occur, it degenerates and istransformed into fibrous tissue called corpus albicans.


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Corpus

Luteum

Corpus

Luteum

Granulosa lutein cellsGranulosa lutein cells


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The oviduct (Uterine tube)The oviduct (Uterine tube)It extends from the ovary to the uterus.It is divided into 4 segments:

1. Infundibulum: funnel-shaped opening, having finger-likeprocesses (fimbriae).

2. Ampulla: the widest part, where fertilization usuallyoccurs.

3. Isthmus: narrow part near to uterus.4. Intramural part: traverses the uterine wall.

Histology of the OviductMucosa: highly folded and is formed of

A. Epithelium: simple columnar, partly ciliated (to move the ovumtoward the uterus) and partly non-ciliated (secretory cells,nutritive to the ovum).

B. Lamina propria: connective tissue rich in blood vessels.1. Musculosa: inner circular and outer longitudinal smooth

muscle fibers.2. Serosa: areolar connective tissue covered by simple


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The oviduct


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Hormonal

control of

femalecycle


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Female

ReproductiveCycle


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The oviductThe oviductThe oviductThe oviductIt extends from the ovary to the uterus.It is divided into 4 segments:

1. Infundibulum: funnel-shaped opening, having finger-likeprocesses (fimbriae).2. Ampulla: the widest part, where fertilization usually

occurs.3. Isthmus: narrow part near to uterus.

4. Intramural part: traverses the uterine wall.

Histology of the OviductMucosa: highly folded and is formed of

A. Epithelium: simple columnar, partly ciliated (to moved the ovumtoward the uterus) and partly non-ciliated (secretory peg cells,nutritive to the ovum).

B. Lamina propria: connective tissue rich in blood vessels.1. Musculosa: inner circular and outer longitudinal smooth

muscle fibers.

2. Serosa: areolar connective tissue covered by simple


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The oviduct


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The UterusThe UterusIt is a thick-walled pear-shaped organ which has a narrowlumen.

It is formed of body and cervix.The body is formed of 3 layers:

1. Endometrium.2. Myometrium.

3. Perimetrium.The endometrium

It is lined by simple columnar epithelium.Its lamina propria contains simple tubular mucous glands lined

by columnar epithelium and may reach to the myometrium.It undergoes cyclic changes in response to ovarian hormones.It is divided into superficial layer (stratum functionalis) anddeep layer (stratum basalis).


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Uterine wall


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The myometrium

3 layers of smooth muscle fibers and connective tissue.They are not easily distinguished from each other.

The middle layer is called stratum vascularis and containsnumerous large blood vessels.During pregnancy, the smooth muscle fibers increase in length.

The perimetrium

It is formed of areolar connective tissue, blood vessels andcovered by simple squamous mesothelium.

Cyclic changes of the endometrium1. Menstrual stage (from day 1 day 5).

2. Proliferative phase (from day 6 day 16).

3. Secretory phase (from day 17 day 26).

4. Premenstrual stage (from day 27 day 28).

(1) M t l St


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(1) Menstrual StageDue to hormonal deficiency specially progesterone.

Constriction of coiled arteries for long periods causes ischemia

and rupture of capillaries.Glands fragment and uterine fluid, tissue debris and blood are

sloughed out and discharged through vagina.

Stratum functionalis is lost.

(2) P lif ti St


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(2) Proliferative StageOccurs during maturation of follicles till ovulation.

Under the effect of estrogen secreted by the follicles.

It is the stage of regeneration of the stratum functionalis fromstratum basalis.

Epithelium of basal

glands recovers the

raw surface.Glands increase in

length, become

straight and uniform.

Endometriumincreases in

thickness from 0.5

mm to 2-3 mm.

(3) S t St


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(3) Secretory StageRelated to the formation of corpus luteum.

Under the effect of progesterone and estrogen secreted by theluteal cells.

Endometrium becomes hypertrophied and vascular to reaches itsfull thickness (4-5 mm).

Endometrial glands become coiled (cork-screw).

The glandular lumen contains secretions & rich in glycogen.

(4) P t l St


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(4) Premenstrual StageRelated to the involution of the corpus luteum and formation ofcorpus albicans.

Spiral arteries undergo periodic constriction leading to stasis incapillaries and periods of ischemia.

Glands stop secretion leading to shrinkage of stratumfunctionalis due to water loss.

The thickness of the endometrium decreases.

Stratum

functionalis

appears deeplystained because of

the closely packed

stromal cells.


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Hormonalcontrol

&

Menstrualcycle

Th C i

Th C i


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The CervixThe Cervix

It consists of:

1. Endometrium: Epithelium: simple columnar mucous-

secreting epithelium. Lamina propria: contains branched tubular

glands secreting mucous. The cervical endometrium does not change

during the menstrual cycle, only the amount

and consistency of the mucous change.1. Myometrium: dense connective tissue andfew amount of smooth muscle fibers.

2. Adventitia: connective tissue (no peritoneum)


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Th V iTh V i

Th V iTh V i


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The VaginaThe VaginaThe VaginaThe Vagina

It consists of:It consists of:

1.1. MucosaMucosa:: Epithelium: stratified squamous non-Epithelium: stratified squamous non-

keratinized epithelium rich inkeratinized epithelium rich in

glycogen.glycogen. Lamina propria: contains lymphaticLamina propria: contains lymphatic

nodules but no glands.nodules but no glands.

1.1. MusculosaMusculosa: longitudinal muscle fibers: longitudinal muscle fiberscontinuous with uterine muscles.continuous with uterine muscles.

2.2. AdventitiaAdventitia: dense connective tissue.: dense connective tissue.

It consists of:It consists of:

1.1. MucosaMucosa:: Epithelium: stratified squamous non-Epithelium: stratified squamous non-

keratinized epithelium rich inkeratinized epithelium rich in

glycogen.glycogen. Lamina propria: contains lymphaticLamina propria: contains lymphatic

nodules but no glands.nodules but no glands.

1.1. MusculosaMusculosa: longitudinal muscle fibers: longitudinal muscle fiberscontinuous with uterine muscles.continuous with uterine muscles.

2.2. AdventitiaAdventitia: dense connective tissue.: dense connective tissue.


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The VaginaThe Vagina

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Histology of Female Genital System for Reproductive Module

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