3. HUMAN REPRODUCTION
2. Female Reproductive System
It is located in the pelvic region.
It includes Ovaries, Accessory ducts & External genitalia.
a. Paired
ovaries
- Primary sex organs which produce ova (female gamete) & steroid ovarian hormones (estrogen
& progesterone).
-
Each ovary is 2-4 cm in length.
-
They are located on both side of the lower
abdomen and connected to the pelvic wall and uterus by ligaments.
-
Each ovary is covered by a thin epithelium
which encloses the ovarian stroma.
-
The stroma has outer cortex and
inner medulla.
-
Ovarian cortex contains groups of cells (Ovarian follicles). Each follicle
carries a centrally placed ovum.
b. Accessory ducts (Duct system)
Include 2 oviducts (Fallopian tubes), a uterus & vagina.
Ø Oviducts: Each oviduct (10-12 cm long) has 3 parts:
· Infundibulum: Funnel-shaped opening provided
with many finger-like fimbriae. It
helps to collect the ovum.
· Ampulla:
Wider
part.
·
Isthmus: Narrow
part. It joins the uterus.
The ciliated epithelium lined the lumen of the oviduct drives the ovum
towards the uterus.
Ø Uterus
(womb): It is
inverted pear shaped. It is supported
by ligaments attached to the pelvic wall.
Uterus
has 3 parts: Upper fundus, middle body and terminal cervix. Cervix opens to vagina.
Cervical
canal and vagina forms birth canal.
The
uterine wall has 3 layers:
· Perimetrium:
External thin membrane.
· Myometrium:
Middle thick layer of smooth muscle.
·
Endometrium:
Inner glandular and vascular layer.
Ø Vagina: It opens to the exterior between urethra & anus.
c. External genitalia (vulva or pudendum)
-
Consist of Mons pubis, labia majora, labia minora, hymen & clitoris.
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Mons pubis: A
cushion of fatty tissue covered by pubic hair.
-
Labia
majora: Large, fleshy, fatty and hairy outer folds.
Surrounds vaginal opening.
-
Labia
minora: Small, thin and hairless inner folds.
- Hymen (Maiden
head): A
membrane which partially cover the vaginal opening. It is often torn during the
first coitus. It may also be broken by a sudden fall or jolt, insertion of a
vaginal tampon; active participation in some sports items etc. In some women,
hymen persists after coitus. So the hymen is not a reliable indicator of
virginity or sexual experience.
-
Clitoris:
A highly sensitive organ lying just in front of the urethral opening.
Mammary glands (breasts)
- A pair of mammary glands contains glandular tissue &
fat.
-
Glandular tissue of each breast has 15-20 mammary
lobes containing clusters of cells (mammary alveoli).
- Cells of alveoli secrete milk. It is stored in lumen of
alveoli.
-
The alveoli open into mammary tubules.
-
The tubules of each lobe join to form a mammary
duct.
- Several mammary ducts join to form a wider mammary ampulla which is connected to lactiferous duct through which milk is sucked out.