Introduction.
Reproduction is the ability of an individual to produce a new individual, and is considered as one of vital signs of living organisms,
Human life starts when a male gamete called “Sperm” fuses with a female gamete called “Ovum” to form a single cell called “Zygote”.
Male and female reproductive organs are called “Gonads” they are responsible for production of sex hormones and gametes.
Female and Male Reproductive systems are in dormant stage at birth and become active after onset of Puberty.
The medical specialty which deals with the female reproductive system is called “Gynecology” while the branch of medicine and surgery concerned with childbirth is called “Obstetrics”.
Female reproductive system
Female reproductive system is divided into internal organs and external organs.
External Organs include,
Vulva.
Internal Organs include,
Vagina.
Uterus.
Fallopian Tubes / Oviducts/ Ovarian ducts.
Ovaries.
Mammary Glands.
Vulva (Pudendum):
It is the external genitalia of the female reproductive system.
It has following parts,
Mons pubis.
Labia Majora.
Labia Minora.
Clitoris.
Vestibule.
Mons pubis:
It is a pad of adipose tissue lying in front of the pubic symphysis.
The mons pubis is a rounded eminence made by fatty tissue beneath the skin.
In humans, it generally is more prominent in females than in males.
At puberty, the hairs on it become coarser and more numerous.
Labia Majora:
The labia majora are two marked folds of skin that extend from the mons pubis downward and backward to merge with the skin of the perineum.
They form the lateral boundaries of the vulva or pudendum.
The outer surface of each labium is pigmented and hairy; the inner surface is smooth but possesses sebaceous glands.
The labia majora contains fat and loose connective tissue and sweat glands.
It correspond to the scrotum in the male
Labia Minora:
They are smaller folds that lie inside the labia majora.
They lack fat and hair.
Clitoris:
It corresponds to penis of male and enlarges on excitation.
Located at the anterior junction of labia minora.
Composed of two corpora cavernosa separated by a partition.
It possesses a sensitive tip of spongy erectile tissue, the glans clitoridis.
Vestibule:
It is the region between labia minora.
It contains an opening of vagina guarded by Hymen.
Opening of the urethra is present above the vaginal opening.
Two Bartholin's Glands are present on either side of the vaginal opening; it secretes small quantities of mucus during sexual arousal and intercourse.
The bulb of the vestibule, corresponding to the bulb of the penis, is two elongated masses of erectile tissue that lie one on each side of the vaginal opening.
Vagina:
It is about 10 cm long fibromuscular canal present between external body opening (Vestibule) and Cervix of Uterus.
In virgins the exterior opening i.e. Vestibule is covered by a Membrane called Hyamen.
The main functions of vagina:
Female organ of copulation.
Receives sperm.
Act as a tract for excretion of menstrual waste.
Birth canal.
Structure:
Three main layers,
Mucosa.
Muscularis.
Adventitia.
Mucosa is made up of non keratinized stratified squamous epithelium and areolar connective tissue, placed in folds called rugae.
Cells of mucosa contain large deposits of glycogen which on decomposition produces organic acids that kill microbes present in the canal, but may also be harmful for the sperms.
Muscularis is composed of smooth muscles.
Adventia is a layer of connective tissue that surrounds the vagina.
Uterus:
It is a pear shaped organ present between the urinary bladder and rectum.
It is supplied with two fallopian tubes on either side.
It acts as a site for implantation of embryos.
When not holding the pregnancy it is 7 cm long, 5 cm wide and 2.5 cm in thickness.
Its size changes dramatically while holding the pregnancy as per the size of foetus.
Its linings form the main part of menstrual wastes.
Structurally it is divided into,
Fundus: Dome shaped part between two fallopian tubes,
Body: Tapering central part which ends at cervix.
Cervix: Mouth of uterus, it opens into vagina. (Its opening is called external oss).
The part present between body and cervix is called isthmus,
Histologically it is divided into three layers,
Perimetrium: Outer. Mainly connective tissue.
Myometrium: Middle. Smooth Muscles.
Endometrium: Inner. Epithelium and glandular tissue.
The endometrium has two layers as,
Stratum functionalis: Sheds off during menstruation.
Stratum basalis: Behind the stratum functionalis and it is a permanent layer.
After fertilization in fallopian tubes the embryo is implanted in uterine walls for further growth.
If an embryo gets implanted in other sites than the uterus the pregnancy is called “Ectopic Pregnancy”.
4. Fallopian Tubes:
Also called “Ovarian Ducts”, “Uterine tubes,”.
There are two 10 cm long fallopian tubes arising from either side of the fundus of the uterus.
Fertilization takes place here.
Its a passage for sperms and zygote if fertilization takes place.
Structurally it is divided into three parts as,
Infundibulum:
Funnel shaped part and opening of the fallopian tube.
It opens near the ovary and has finger-like projections called fimbriae.
Ampulla:
It is the middle widest part of the fallopian tube.
It is the actual place where fertilization takes place.
Isthmus:
Last thick short part that joins the uterus.
Histologically it has three layers,
Mucosa: Contains simple ciliary columnar epithelium.
Muscularis: Contains smooth muscles that facilitate movements.
Serosa: Outermost layer of connective tissue.
5. Ovaries:
Female Gonads, produces,
Gamete: Ovum.
Hormones: Oestrogen, Progesterone, Inhibin, Relaxin.
There are two ovaries each lying on either side of the uterus, various ligaments keep them in the position.
Structurally they are 2.5 to 3.5 cm long, 2 cm wide, and 1 cm thick.
Each kidney has a “Hilum” which serves as an entry and exit point for nerves, blood vessels etc.
Histology: Each ovary consists of following structures,
Germinal Epithelium:
It is a large layer of simple epithelium that covers the surface of the ovary.
Tunica albuginea:
It is a dense whitish irregular connective tissue present just after the germinal epithelium layer.
Ovarian Cortex:
Present just below the tunica albuginea.
It contains ovarian follicles surrounded by dense irregular connective tissue which also contain scattered smooth muscle cells.
Ovarian Medulla:
Present below the ovarian cortex,
Contains loose connective tissue, blood vessels, lymph vessels and nerves.
Ovarian Follicles:
Present in cortex, contains oocytes in various stages of development.
The nearby cells provide nourishment to the developing oocytes and secrete estrogen.
Mature Graafian Follicle:
It is a large fluid filled mature follicle that ruptures to release the ovum (Secondary oocyte).
Corpus Luteum:
It is the remaining part of the graafian follicle after releasing the ovum.
It produces various hormones like progesterone, estrogen, elastin, and inhibin.
Corpus albicans:
It is a degenerated corpus albicans with a white fibrous mass.
Commonly Asked Questions:
Write in detail about the female reproductive system.
With a well labelled diagram describing the female reproductive system.
With a well labelled diagram describing the cross section of human ovary.