Female Reproductive SystemObjectives: Understand and identify the stages of ovarian

follicular growth as well as the changes that occur in the follicular wall during pregnancy.

Identify the regional variations in the structure of the oviduct (Fallopian tube).

Describe the structure and the changes that occur in the ovary, and uterus during the menstrual cycle.

Describe the changes that occur in the mammary glands before and after pregnancy.

Describe the histological structure of vagina and placenta.

ADULT OVARYADULT OVARY

1-1- Germinal epithelium:Germinal epithelium: outer layer of flat cells. outer layer of flat cells.

2-2- Tunica albuginea:Tunica albuginea: dense C.T layer. dense C.T layer.

3-3- Cortex:Cortex: contains ovarian follicles and interstitial stromal contains ovarian follicles and interstitial stromal cells.cells.

4-4- Medulla:Medulla: highly vascular loose C.T. highly vascular loose C.T.

Ovarian FolliclesOvarian Follicles

PRIMORDIAL folliclesPRIMORDIAL follicles PRIMARY follicles:PRIMARY follicles:

– UnilaminarUnilaminar– MultilaminarMultilaminar

SECONDARY (ANTRAL) SECONDARY (ANTRAL) folliclesfollicles

MATURE Graafian MATURE Graafian folliclesfollicles

ATRETIC folliclesATRETIC follicles

Primordial FolliclesPrimordial Follicles

Earliest and most Earliest and most numerous stage.numerous stage.

Located superficially Located superficially under the tunica under the tunica albuginea.albuginea.

Each follicle is Each follicle is formed of a formed of a primary primary oocyteoocyte (25 µm), (25 µm), surrounded by a surrounded by a single layer of flat single layer of flat follicular cellsfollicular cells..

Primary FolliclesPrimary Follicles

Develop from the Develop from the primordial follicles, at primordial follicles, at puberty under the puberty under the effect of FSH.effect of FSH.

a)a) Unilaminar primary Unilaminar primary follicles:follicles:

The primary oocyte is The primary oocyte is larger (40 larger (40 m)m)

The follicular cells The follicular cells are cuboidal in are cuboidal in shape.shape.

Primary FolliclesPrimary Follicles

b)b) Multilaminar Multilaminar primary follicles primary follicles (Pre-antral (Pre-antral follicles):follicles):

oocyte largeroocyte larger corona radiatacorona radiata granulosa cellsgranulosa cells zona pellucidazona pellucida theca folliculitheca folliculi

Ovarian Follicles (Cont.)Ovarian Follicles (Cont.)

Secondary Follicles:

between the stratified granulosa cells,

there are large lacunae that coalesce to

form the follicular antrum.

The stromal cells surrounding the follicle have

differentiated to form an inner layer (theca interna) of cells that secrete steroid precursors and an outer layer (theca externa) composed of concentrically arranged stromal cells that provide support for the developing follicle

Mature (Graafian) FollicleMature (Graafian) Follicle

large, thin walledlarge, thin walled wide follicular antrumwide follicular antrum large oocytelarge oocyte zona pellucidazona pellucida corona radiatacorona radiata cumulus oophoruscumulus oophorus zona granulosazona granulosa basement membranebasement membrane theca folliculitheca folliculi

Follicular growthFollicular growth

Atretic FolliclesAtretic Follicles

During growth of the ovarian follicles, many During growth of the ovarian follicles, many of them do not reach maturation and they of them do not reach maturation and they degenerate, and finally replaced completely degenerate, and finally replaced completely by fibrous tissue and are called by fibrous tissue and are called atretic atretic folliclesfollicles or corpora atretica. or corpora atretica.

Corpus LuteumCorpus Luteum

zona granulosa zona granulosa granulosa lutein cellsgranulosa lutein cells

Theca interna Theca interna theca theca lutein cellslutein cells

Bleeding may occur Bleeding may occur corpus haemorrhagicumcorpus haemorrhagicum

Fertilization Fertilization corpus corpus luteum of pregnancyluteum of pregnancy

No fertilization No fertilization corpus corpus luteum of menstruationluteum of menstruation

At the end At the end corpus corpus albicansalbicans

Corpus luteum cCorpus luteum contains:ontains:1. Granulosa lutein cells: secrete progesterone+ small amount of estrogen2. Theca lutein(interna): secrete estrogen.

There are 2 types of corpus luteum:There are 2 types of corpus luteum: a- Corpus luteum of menstruation lasts 14 day. b- Corpus luteum of pregnancy lasts 4 months.

Corpus AlbicansCorpus Albicans

• Is formed due to involution of corpus luteum (degenerated corpus luteum)

• Secretory cells of corpus luteum undergoes degenerations and are phagocytosed by macrophages.

FALLOPIAN TUBES (OVIDUCTS)FALLOPIAN TUBES (OVIDUCTS)

Fallopian TubesFallopian Tubes

Mucosa:Mucosa:– Highly folded.Highly folded.– Simple Columnar Simple Columnar

Epith. partially ciliated.Epith. partially ciliated.– Corium of C.T.Corium of C.T.

Musculosa:Musculosa:– Inner circularInner circular– Outer longitudinalOuter longitudinal

SerosaSerosa

Fallopian TubesFallopian Tubes

Epithelium lining of the Epithelium lining of the mucosa:mucosa:Ciliated cells:Ciliated cells:

– Non-secretoryNon-secretory– Cilia beat toward uterusCilia beat toward uterus

Non-ciliated cells:Non-ciliated cells:– Thinner, also called peg cellsThinner, also called peg cells– Secretory cellsSecretory cells– Apices bulge above ciliated Apices bulge above ciliated

cellscells– Their apices contain nutritive Their apices contain nutritive

material to nourish gametesmaterial to nourish gametes

UTERUSUTERUS

Thick-walled Thick-walled muscular organmuscular organ

Inverted pear Inverted pear shape.shape.

Anatomically:Anatomically:– Body:Body: upper 2/3 upper 2/3– Cervix:Cervix: lower 1/3 lower 1/3– Fundus:Fundus: the the

rounded dome-rounded dome-shaped top of shaped top of the bodythe body

Fundus & BodyFundus & Body

Consist of:Consist of:– EndometriumEndometrium

(mucosa)(mucosa)– MyometriumMyometrium

(musculosa)(musculosa)– PerimetriumPerimetrium

(serosa or (serosa or adventitia)adventitia)

EndometriumEndometrium

Epithelium:Epithelium: simple simple columnar partially columnar partially ciliatedciliated

Corium:Corium:– Endometrial glands: Endometrial glands:

simple tubularsimple tubular– Stromal cellsStromal cells– Blood vesselsBlood vessels– LeucocytesLeucocytes– Reticular fibresReticular fibres

Endometrium; Endometrium; Blood supplyBlood supplyTwo types of arteries Two types of arteries derived from vessels in derived from vessels in the myometrium:the myometrium:

CoiledCoiled arteries: arteries:– extend into the extend into the

functional zone functional zone (stratum functionalis) (stratum functionalis) (superficial layer)(superficial layer)

– cyclic changescyclic changes StraightStraight arteries: arteries:

– terminate in basal terminate in basal zone (stratum basalis) zone (stratum basalis) (basal layer)(basal layer)

– no cyclic changesno cyclic changes

MyometriumMyometrium

3- ill-defined smooth 3- ill-defined smooth muscle layers:muscle layers:– Stratum submucosumStratum submucosum: :

longitudinallongitudinal– Stratum vasculare:Stratum vasculare:

circular smooth muscle circular smooth muscle fibres in figure of 8 fibres in figure of 8 arrangement around arrangement around large blood vesselslarge blood vessels

– Stratum supravasculare:Stratum supravasculare: longitudinallongitudinal

Endometrium; Menstrual CycleEndometrium; Menstrual Cycle

Proliferative stage of the uterus Glands have proliferated and cover the

surface. The spiral arteries are elongated and convoluted, and extend from the basal layer into the functional layer.

Secretory phase of the Uterus Glands of the secretory phase endometrium appear

convoluted. Toward the end of this phase, apical tissues become ischemic and glands take on a characteristic “saw tooth” appearance.

The endometrium reaches its maximal thickness during this period, and spiral arteries continue to grow and extend into the superficial regions of the functional layer. There is also considerable leukocyte infiltration in the stroma.

Uterine CervixUterine Cervix

Mucosal lining:Mucosal lining:– Epithelium:Epithelium: simple simple

columnar in the cervical columnar in the cervical canal, but it changes to canal, but it changes to stratified squamous epith. stratified squamous epith. (non-keratinized) at the (non-keratinized) at the external osexternal os

– Corium: Corium: CT containing CT containing tubulo-alveolar glandstubulo-alveolar glands

Wall of the cervix:Wall of the cervix: dense dense fibrous tissue with elastic fibrous tissue with elastic fibers and few smooth fibers and few smooth muscle fibers.muscle fibers.

PLACENTAPLACENTA

1- Fetal part: 1- Fetal part:

Chorionic plate and chorionic villi.Chorionic plate and chorionic villi.

2- Maternal part:2- Maternal part:

Decidua basalis.Decidua basalis.

Chorionic villus is formed of: Chorionic villus is formed of:

1- Central core of mesenchymal C.T.1- Central core of mesenchymal C.T.

2- Fetal blood capillaries.2- Fetal blood capillaries.

3- Trophoblasts:3- Trophoblasts:

a- Syncytiotrophoblas : superficial & a- Syncytiotrophoblas : superficial &

darkly-stained. darkly-stained. b- Cytotrophoblasts: disappear in b- Cytotrophoblasts: disappear in late pregnancy. late pregnancy.

Placenta of early pregnancy

Placenta of late pregnancy

PlacentaPlacenta

The Placental Barrier:The Placental Barrier: It is the It is the barrier between maternal blood in the barrier between maternal blood in the intervillous spaces and foetal blood in the intervillous spaces and foetal blood in the fetal blood capillaries in the chorionic villi fetal blood capillaries in the chorionic villi . It consists of: . It consists of:

1.1. The trophoblasts covering The trophoblasts covering the the villus.villus.

2.2. The basement membrane of The basement membrane of the trophoblasts.the trophoblasts.

3.3. The C.T. core of the villus.The C.T. core of the villus.

4.4. The basement membrane of The basement membrane of foetal blood capillaries.foetal blood capillaries.

5.5. The endothelium of foetal The endothelium of foetal blood capillaries.blood capillaries.

VAGINAVAGINA MucosaMucosa:: shows transverse shows transverse

folds and is made of:folds and is made of:– Epithelium: stratified Epithelium: stratified

squamous epithelium non-squamous epithelium non-keratinized, rich in glycogen.keratinized, rich in glycogen.

– Corium: of C.T., very rich in Corium: of C.T., very rich in blood vessels, elastic fibres blood vessels, elastic fibres and leucocytes.and leucocytes.

MusculosaMusculosa:: formed of formed of inner circular and outer inner circular and outer longitudinal layers of longitudinal layers of smooth muscle fibres.smooth muscle fibres.

AdventitiaAdventitia:: formed of formed of loose C.T. rich in elastic loose C.T. rich in elastic fibres.fibres.

MAMMARY GLAND

Non-lactating mammary glandNon-lactating mammary gland

Consists of few clusters of Consists of few clusters of intralobular small ducts (lined intralobular small ducts (lined with simple cuboidal epith.) and with simple cuboidal epith.) and intralobular loose connective intralobular loose connective tissuetissue.. The majority of the gland, is a The majority of the gland, is a mass of dense, fibrous connective mass of dense, fibrous connective tissue (forming the interlobar and tissue (forming the interlobar and the interlobular septa) with the interlobular septa) with collections of adipose tissue.collections of adipose tissue.

Lactiferous ducts: are lined with Lactiferous ducts: are lined with stratified columnar epith.stratified columnar epith.

Lactiferous sinuses and terminal part of Lactiferous sinuses and terminal part of lactiferous ducts: are lined with str. lactiferous ducts: are lined with str. Squamous epithSquamous epith..

Mammary gland during pregnancyMammary gland during pregnancy

1-Each lobule will be enlarged while the inter- and intra-lobular connective tissues are decreased.

2-Terminal ends of the intralobular ducts show dilated acini (alveoli) that are lined with low columnar or cuboidal epith. and myoepithelium.

Lactating mammary glandLactating mammary gland

1-Marked reduction of interlobular tissue.

2-Marked reduction of intralobular C.T.

3-Markedly distended acini (alveoli) with milk.

4-Acini are lined with flat epith.

NB. Suckling stimulates prolactin and oxytocin hormones secretion.

Mechanism of milk secretion

1- Merocrine: For Protein. 2- Apocrine: For Lipid.

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