Female Reproductive System

Female Reproductive SystemFemale Reproductive System

OVARY

• Female Gonads

• Paired

• Lie in the peritoneal cavity

• Suspended by suspensory ligament

Cortex – Connective Tissue & Ovarian FolliclesMedulla – Blood Vessels, lymphatics & Nerves

Surface of ovary – covered by single layer of cuboidal cells (wrongly termed germinal epithelium) Tunica Albugenia – Thick connective tissue layer between the germinal epithelium and underlying cortex.

FOLLICULAR ORGANIZATION

• PRIMORDIAL FOLLICLE. • Most numerous of the follicles in the

cortex.

• Oocyte surrounded by a single layer

of squamous cells. • The oocyte is called primary oocyte

and is in prophase of first meiotic division.

• Further meiotic activity arrested

Follicle stimulating hormone (FSH) from the pituitary -follicular maturation

Follicular or granulosa cells, enlarge - a single layer of cuboidal cells

Follicle enlarges in size - primary follicle

A layer of glycoprotein (zona pellucida) - around the oocyte

Primary Follicle

Connective tissue -two distinct zones, the theca interna (Ti) next to the follicular cells outer theca externa continuous with the stroma.Theca interna cells - steroid secreting cells

Mitoses of granulosa cells produce a multilaminar (many layers of granulosa cells) primary follicle.

Appearnce of fluid filled cavity( Antrum) – Secondary Follicle

Oocyte is surrounded by several layers of granulosa cells - corona radiata

Oocyte rests on a small hill of granulosa cells -cumulus oophorus.

Antrum contains a hormone-rich fluid secreted by the granulosa cells

SECONDARY FOLLICLE

Theca Externa

Cumulus OophorusTheca Interna

Corona Radiata

antrum

GRAAFIAN FOLLICLE

Continued maturation and enlargement of secondary follicle - Graafian follicle (mature follicle) - prior to ovulation

Oocyte and corona radiata cells rest on cumulus oophorus.

The theca interna (T) is located exterior to the granulosa cells.

CORPUS LUTEUM

• Ovulation -release of the ovum -loss of antral fluid

• Rearrangement of granulosa cells and theca interna cells

• Hormones - corpus luteum (CL) inhibit pituitary LH and FSH preventing ovulation of other follicles.

• In pregnancy - corpus luteum - 4-5 months -placental human chorionic gonadotropin (HCG)

• No pregnancy - corpus luteum degenerates – corpus albicans.

• GRANULOSA LUTEIN CELLS

• Large, round cells with a central nucleus

• Secrete progesterone.• THECA LUTEIN CELLS: • Theca interna cells retain

their linear characteristics -theca lutein cells

• Interspersed between the granulosa lutein cells -fewer in number.

• Secrete progesterone and androgens.

• CORPUS ALBICANS :

• Corpus luteum - fibrotic - cells removed by macrophages - white scar in the ovary-corpus albicans.

• ATRETIC FOLLICLE : • Number of primordial follicles respond to FSH (or to local

factors) • Usually one ovum released -ovary at ovulation. • Others degenerate - atretic follicles - breakdown of the

oocyte, zona pellucida and granulosa cells occurs.

• pair of fibromuscular tubes • conducts ova expelled from ovary to the uterus.• PARTS

– INFUNDIBULUM– AMPULLA– ISTHMUS– INTRAUTERINE

• mucosa thrown in to longitudinal folds -exaggerated in infundibulum and ampulla.

FALLOPIAN TUBE

• OVIDUCT CELLS – 2distinct types• Ciliated simple columnar epithelial cells – most numerous –

infundibulum and ampulla• Secretory cells – nonciliated & wedged in between the ciliated cells -

also called peg cells(arrow) - nutritive material for ovum.• The ciliated cells keep the fluids secreted by the peg cells in motion • Ciliary movements and peristaltic muscular activity involved -

movement of the oocyte.

• Muscular organ -provide a protective and nutritive environment -developing fetus

• Three parts Fundus, body and cervix. • Uterine wall - three layers; -perimetiurm lined by serosa or adventitia; -thick smooth muscle layer called myometrium - inner endometrium.

• Myometrium - interlacing bands of smooth muscle fibers - contract under the influence of oxytocin at parturition.

• Undergo Hyperplasia and hypertrophy -pregnancy.

Endometrium

• The endometrium - functional (decidua functionalis) and basal (decidua basalis) regions.

• functional area changes dramatically -course of each cycle - lost if pregnancy does not occur.

• Basal portion - close to myometrium - retained -menstruation - stem cells for the functionalis - next cycle.

• There are three stages of endometrial cycling.

PROLIFERATIVE STAGE:

• cessation of menstruation - endometrium - proliferative phase -glands and blood vessels increase in size, - influence of estrogen from the ovary.

• influence of ovarian estrogen - the uterine endometrium lengthens.

• Uterine tissues, both glandular and stromal tissues, proliferate

• SECRETORY STAGE

• Commences with ovulation.

• Endometrium attains its greatest height - Progesterone - corpus luteum - main-tains the endometrium.

Endometrial glands - cork-screw in shape- lining cells secrete nutrients, especially glycogen, into the lumen - dilates the glandular lumen.Spiral arteries - lengthen, become coiled and extend almost to the surface.

• MENSTRUAL STAGE • the stroma - engorged

with blood. • walls of blood vessels

become leaky - glandular epithelium degenerates.

• entire functionalis - lost during menstruation

• basal layer of the endometrium persists as a small area of tissue adjacent to the myometrium.

• CERVIX • Neck of the uterus or

cervix extends into the vaginal canal.

• Ectocervix: cervix extending into the vagina - lined by stratified squamous non keratinized epithelium

• Endocervix: mucous membrane lining the cervical canal - region of the opening of the cervical canal into the uterine cavity

• wall -contains dense connective tissue -relatively little smooth muscle

• Mucus secreting glands located in irregular outlines of mucosa.

• Ducts from these glands can become occluded - cysts ( Nabothian cysts).

• VAGINA • fibromuscular canal – non

keratinized stratified squamous epithelium

• lamina propria - • vagina does not contain glands.• Layer of smooth muscle -inner

circular and outer longitudinal coats.

• Striated muscle fibers may be present

• adventitia.• During follicular phase of the

menstrual cycle, the epithelial cells of the vagina store glycogen.

• Glycogen - washed out of the cells in the preparative procedures for light microscopy - the outer layers of cells appear pale with small darkly stained nuclei.

• MAMMARY GLANDS • 15-25 lobes - Compound tubuloalveolar glands • Glandular elements - arranged in a radial fashion around the nipple into

which ducts from the secretory units empty.• Histology varies with age and the physiological state of the individual. • Affected by a variety of hormones from the ovary, placenta and pituitary.

• INACTIVE GLAND• Glandular component- Duct elements• Early in Cycle- ducts with little or no lumen• Ovulation- secretory cells increase in height, fluid

accumulates in connective tissue . • flattened nuclei of fibroblasts - connective tissue

between the alveoli.

• morphologically similar - thyroid or the lung because of this activity.

• well developed system of ducts• Ducts and glands - greatest

development - last stages of pregnancy.

• The lumen filled with their secretions.

• myoepithelial cells - stimulated to contract - oxytocin - suckling.

• Contractions of myoepithelial cells force milk from the alveoli into the duct system.

• Prolactin secretion and milk production continue as long as the child suckles.

• Weaning - regression of breast tissue - resumption of the ovarian cycle

Lactating Gland

• PLACENTA

• Exchange of material between the fetus and the mother

• Two parts - the fetal part and the maternal part.

• CHORIONIC VILLUS

• outer syncytiotrophoblast layer of basophilic cells

• The syncytiotrophoblastic cells secrete human chorionic gonadotrophin

• connective tissue core of the villi- branches of the umbilical arteries and vein. Fibroblasts and phagocytic cells (Hofbauer's cells) also found .

• Intervillous spaces -maternal blood.

• Immediately below the syncytio-trophoblast layer -cyto-trophoblast cells -abundant in early stages of pregnancy.

• placenta at term the number of cells in this layer is greatly reduced.