female reproductive system

Female reproductive system

group

of organs that produces oocytes and sex

hormones, provides the site for

fertilization, and supports embryo and

fetal development until birth.

• Consists of the:

• Paired Ovaries and Oviducts (uterine

tubes)

• Uterus

• Vagina

• External genitalia

Ovaries

almond-shaped organs

responsible for oocyte production and steroid

hormone secretion.

tunica albugine

Each ovary is covered by a surface (germinal)

epithelium and a dense connective tissue

capsule called

Ovarian cortex

contains highly cellular

connective tissue with numerous ovarian

follicles, while the medulla contains loose

connective tissue and blood vessels; there is no

sharp boundary between the two.

Ovaries microscopy

Ovarian follicles

is a functional unit

consisting of an oocyte surrounded by

follicular (granulosa) cells and a basal

lamina.

Hormonal regulation stages

• Primordial

• Primary

• Secondary (antral)

• Mature (Graafian)

Primordial follicle

• Primary oocyte arrested in prophase I

• Surrounded by a single layer of flattened

follicular cells

• Located in the superficial ovarian cortex

• Present from fetal life

Unilaminar Primary Follicle

• Oocyte increases in size

• Surrounded by a single layer of cuboidal

follicular (granulosa) cells

• Zona pellucida begins to form

• No antrum present

Primary follicle

Unilaminar primary follicle

Multilaminar primary follicle

Unilaminar Primary Follicle

• Oocyte increases in size

• Surrounded by a single layer of cuboidal

follicular (granulosa) cells

• Zona pellucida begins to form

• No antrum present

Multilaminar primary follicle

• Oocyte continues to enlarge

• Surrounded by multiple layers of granulosa cells

• Well-defined zona pellucida

• Follicle remains avascular and lacks an antrum

SECONDARY FOLLICLE

• Appearance of a fluid-filled antrum

• Theca interna and theca externa are well defined

• Actively produces estrogen

(Antral)

Mature follicle

(Graafian)

• Very large follicle with a single, prominent antrum

• Oocyte surrounded by corona radiata and attached by

the cumulus oophorus

• Bulges at the ovarian surface

• Ready for ovulation

Corpus luteum

temporary endocrine gland

formed from the ruptured ovarian follicle after

ovulation.

• It secretes progesterone and estrogens to prepare

and maintain the endometrium for implantation.

• If pregnancy occurs, it is maintained by human

chorionic gonadotropin (hCG).

• If pregnancy does not occur, it degenerates after about

10–12 days (mensturation).

Corpus albicans

is the fibrous, scar-

like remnant formed from the degenerated

corpus luteum.

• It consists mainly of dense connective

tissue.

• It has no hormonal function and gradually

regresses over time.

Uterine tube

paired structures that

transport the oocyte and are the usual site of

fertilization.

• They are divided into:

• Infundibulum (with fimbriae)

• Ampulla (site of fertilization)

• Isthmus

• Uterine part.

Uterine tube microscopy

The wall consists of:

• Folded mucosa with

ciliated and secretory

cells

• Smooth muscle layer

for peristalsis

• Outer serosa

Uterus

a pear-shaped, thick-

walled muscular organ that

supports implantation, pregnancy,

and parturition.

• It consists of the fundus, body,

cervix, and isthmus

Uterine wall

• Perimetrium (outer serosa/adventitia)

• Myometrium (thick smooth muscle

layer responsible for contractions)

• Endometrium (inner mucosa that

undergoes cyclic hormonal changes)

endometrium

divided into a basal

layer (permanent) and a functional layer

(cyclically thickens and is shed during

menstruation).

Uterus microscopy

Cervix

the lower, cylindrical portion of the uterus

that connects the uterine cavity to the vagina.

Cervical canal

the passage within the cervix

that connects the uterine cavity to the vagina.

Internal os

the opening of the cervical canal

into the uterine cavity.

External os

the opening of the cervical canal

into the vagina.

transformation zone

area in the cervix where simple columnar epithelium (endocervix) meets

stratified squamous epithelium (ectocervix).

• It is located near the external os and shifts position with age, hormonal changes, and pregnancy.

• This zone is clinically important because it is the most common site of cervical epithelial dysplasia and

cervical carcinoma.

Vagina

fibromuscular canal that

connects the cervix to the external genitalia

and serves as the copulatory organ and birth

canal.

lacks glands; lubrication

comes mainly from cervical mucus and

vestibular glands.

• Rich elastic fibers and smooth muscle

allow distensibility during intercourse

and childbirth.

Vagina layers

• Mucosa (stratified squamous

nonkeratinized epithelium)

• Muscular layer (smooth muscle)

• Adventitia (connective tissue)

Vaginal epithelium

glycogen under estrogen influence;

bacterial metabolism produces lactic

acid, creating an acidic pH that protects

against pathogens.

External genitalia

(Vulva)

collectively called the vulva,

are the external structures of the female

reproductive system.

• Components include the vestibule, labia minora,

labia majora, and clitoris.

• These structures are covered by stratified

squamous epithelium and are richly supplied with

sensory nerves.

• The vulva plays an important role in protection of

the vaginal opening and sexual arousal.

Labia majora

skin with hair follicles, sebaceous &

sweat glands

Labia minora

thin skin, no hair, richly vascular

and innervated

Clitoris

Erectile tissue, highly innerveted

Vestibule

openings of urethra and vagina;

Bartholin (greater vestibular) glands open here