FEMALE ORGANS OF REPRODUCTION

 The female reproductive organs are broadly divided into the following ways (Fig. 2.1):-

1. External Reproductive Organs
2. Internal Reproductive Organs
3. Accessory Reproductive Organs

A. EXTERNAL REPRODUCTIVE ORGANS

As a whole external female genital organs are known as vulva. Vulva is the composite name for the external genitalia comprising the mons pubis, the labia majora, and the labia minora. The clitoris, the vaginal orifice, urethral orifice, fourchette and the vestibule (Fig 2.2).

Mons Pubis

• The mons pubis, or mons veneris, is the rounded soft fullness of subcutaneous fatty tissue and loose connective tissue over the symphysis pubis. It contains many sebaceous glands and develops course dark, curly hair at puberty, about 1-2 years before the onset of menses.
• The mons plays a role in sensuality and protects the symphysis pubis during coitus (sexual intercourse)

Labia Majora

• The labia majora are two rounded, lengthwise folds of skin-covered fat and connective tissue that merge with the Mons.
• They extend from the mons downward around the labia minora.
• The labia majora protect the labia minora, urinary meatus, and vaginal.

• On the lateral surfaces, labial skin is thick, usually pigmented darker than surrounding tissues, and covered with coarse hair (similar to that of the mons) that thins out towards the perineum. The medial surfaces of the labia majora are smooth, thick, and hairless

Labia Minora

• The labia minora, located between the labia majora are narrow, lengthwise folds of hairless skin.
• The lateral and anterior aspects of the labia are usually pigmented.
• The medial surfaces are similar to the vaginal mucosa and are pink and moist.
• The space between the labia minora is called the vestibule.

Clitoris

• The clitoris is a short, cylindrical, erectile organ located just beneath the arch of the pubis; the visible portion is about 6 x 6 mm or less in the unaroused state.
• The tip of the clitorial body is called the glands and is more sensitive than its shaft.
• Whenever a woman is sexually aroused, the glands and shaft increase in size.

Vestibule

It is a triangular space bounded anteriorly by the clitoris, posterior by the fourchette, and on either side by the labia minora. There are four openings in the vestibule.

• Urethral opening: The opening is situated in the

midline just in front of the vaginal orifice about 1-1.5cm below the pubic arch. The paraurethral ducts open either on the posterior wall.

• Vaginal orifice and hymen: The vaginal orifice lies in the posterior end of the vestibule and is of varying sizes and shapes. The hymen is a thin fold of mucus membrane closed to the circumference of the vaginal orifice, which tears during coitus. During childbirth, the hymen is extremely lacerated and later represented by cicatrized nodules of verifying size, called the carunulae pyriformis.
• Opening of Bartholin's ducts: - There are two Bartholin glands (greater vestibular gland) one on each side. It lies posterior to the vestibular bulb in the superficial perineal pouch. They are pea-sized and yellow with white in colour. During sexual excitement, it secretes abundant alkaline mucus which helps in lubrication.

The duct is about 2cm long and opens at the vaginal orifice external to the hymen.

Fourchette

• This is a thin fold of skin that is formed by the fusion of the labia minora posteriorly and the anterior edge of the perineum.

The perineum:-

• The perineum is the skin-covered muscular area between the vaginal introitus and the anus. The perineum forms the base of the perineal body.
• It is composed of a mass of connective tissues, muscle and fat.
• When the second stage of labour begins. The perineal body begins to be stretched by the descending fetal head. The perineum becomes so thin that it may tear.

B. INTERNAL REPRODUCTIVE ORGANS

The internal female reproductive organs lie in the pelvic cavity which requires a special instrument for inspection. It consists of :

• The vagina
• The uterus
• The uterine (fallopian) tubes
• The ovaries

VAGINA

• The vagina, a tubular structure located in front of the rectum and behind the bladder and urethra extends from the introitus, which is the external opening in the vestibule between the labia minora of the vulva, and the cervix. The vagina is mainly supported by its attachments to the pelvic floor musculature and facia.
  Structure of the vagina: The vagina consists of four layers:-
• The outermost fibrous coat layer is composed of connective tissue.
• The muscle fibres layer is smooth and arranged in outer longitudinal and inner circular layers.
• The submucus layer is composed of loose areolar vascular tissue arranged in many folds known as rugae. The submucus layer resembles erectile tissue and the rugae allow the vaginal wall to stretch during childbirth.
• The mucous coat, lined by stratified squamous epithelium without any secreting glands, is kept moist by the secretion of the mucous gland in the cervix. The acidic nature of the secretions is attributed to the production of lactic acid as a result of the fermentative action of Doderlein's bacilli on the glycogen content of the vaginal epithelial cells.

  Anatomical relation of the vagina

• Anteriorly - Bladder and urethra
• Posterior - Behind the pouch of Douglas, the rectum and the perineal body. Each occupies approximately 1/3 of the posterior vaginal wall.
• Lateral - Upper 2/3* are pelvic fascia and the uterus.
  The lower third is the levator ani muscles of the pelvic floor.
• Superiorly - Above the vagina lies the uterus.
• Inferior - Below the vagina lies external genitalia.

Blood supply is from the uterine and vaginal arteries, branches of internal iliac arteries and branches of uterine arteries.

The venous plexus drains into the internal iliac veins.

Lymphatic drainage is via the inguinal, internal iliac and sacral glands.

Nerve supply - It is provided by the autonomic nervous system by sympathetic and parasympathetic nerve fibres.

In addition, the lower vagina is supplied with sensory nerve fibres from the pudendal nerve.

Functions of the vagina

• It is a passage for the escape of menstrual blood flow.
• It receives a penis during intercourse.
• It provides a way for the fetus during delivery to exit the fetus and placenta. The fetus descends from the uterus through the vagina.

THE UTERUS

• The uterus is a thick, hollow, muscular, pear-shaped organ, located in the pelvis between the urinary bladder in front and the rectum behind.
• The non-pregnant uterus weighs 60, length is 7cm (3 inches), 5 cm (2 inches) wide and 2.5cm (1-2 inches) thick
• It is anteverted inclining forward over the bladder at about a right angle to the vagina and anteflexed bending* slightly forward on itself at the internal os between the corpus and cervix.

Size	Nulliparous Woman	Parous Woman
Length	7.5 cm	8.2 cm
Width at the fundus	2.5 cm	6.2 cm
Each wall is thick	1.25 cm	-
Weight	50 gm	70-80 gm

Position of the uterus

• Normally the uterus is bent forward with its upper part resting on the urinary bladder, ante-flexion (the angle of flexion between the cervix and the body also opens to the front and is about 140 degrees) and the uterus leans forward ante-version (the angle of the version lies between the uterine and vagina axis and is about 90-degree opening to the front).
• In a normal position the fundus is directed to the symphysis pubis and the cervix looks downward and backward.

Structures of the uterus

The body of the uterus is composed of three layers of tissue.

•  Perimetrium: This is an outer layer. It is a thin layer of peritoneum, which covers the fundus, and the anterior surface of the level of the internal os. It is continuous with the broad ligament.
•  Myometrium: It consists of thick bundles of smooth muscle fibres held by connective tissue. This is strong muscle fibre, which is arranged in three layers. The outer layer of the fibres runs longitudinally, the middle layer runs obliquely and the inner layer runs circularly. During the third stage of labour, the myometrium acts as a living ligature by contracting its fibres.
• Endometrium: The inner mucous lining of the cavity is called endometrium which consists of columnar epithelium and glands. It is a highly specialized active membrane of the innermost lining of the uterus. The endometrium is shed every month following menstruation. It is also known as decidua in pregnancy.

Parts of the uterus

• Fundus
• Body
• Isthmus
• Cervix
• Fundus: This is the round dome-shaped upper wall of the corpus where the fallopian tubes enter the uterus.
  The point, at which fallopian tubes to the uterus, is called the cornu or horn.
• Body: This forms the upper 2/3 part of the uterus which is the main part of the uterus. The part lying above the plane of the tubal attachment is known as the fundus uteri.

• Isthmus: This is the narrow space between the cavity and cervix which joins the body of the uterus to the cervix. It forms the lower uterine segment during late pregnancy.
• Cervix: It is cylindrical in shape and measures about 2.5cm. It extends from the isthmus and ends at the external os which opens into the vagina. It has two openings that are called os. The internal os is the area where the cervix meets the isthmus. The external os is a small, round opening at the lower point of the non-pregnant uterus. The cervix contains alkaline fluid.

Support us of the uterus

The uterus is supported by the pelvic floor and several ligaments maintain the position. They are:-

• The round ligaments: In front, it rises from the corner of the uterus and below the fallopian tube. It passes through the inguinal canal and joins to the labia majora. It helps to hold the uterus in anteversion.
• The broad ligaments: They lie on each side laterally.
  Each broad ligament consists of a double fold of peritoneum continuous to the sidewalls of the pelvis.
  It covers the top of the uterus fallopian tube and ovaries like a curtain.
• The uterosacral ligament: It lies posterior part of the uterus and attaches the cervix to the sacrum. By pulling the cervix backwards, it helps to keep the uterus in a position of anteversion.
•  The transverse cervical ligaments: These ligaments are also known as cardinal ligaments. The lower border of each broad ligament is thickened and strengthened by fibrous tissue, fascia and some smooth muscle to the transverse cervical ligament. This joins the cervix to the sidewall of the pelvis. They are important in preventing the uterus from prolapsing into the vagina.

Anatomical relation of the uterus

• Anterior: Above the internal os, the body forms the posterior wall or the uterovesical pouch. So in front uterovesical pouch and bladder lie.
• Posterior: Rectouterine pouch and rectum. It is covered with peritoneum and forms the anterior wall of the pouch of Douglas containing coils of the intestine.
• Laterally: On either side of the uterus the broad ligaments, fallopian tubes and ovaries.
• Superior: Above the uterus intestines lie.
• Inferior: Below the uterus is the internal os and vagina.

Functions of the uterus

•  Menstruation: The thick endometrial is shed every month except during pregnancy during menstruation which flows through the vagina.

• Pregnancy: The uterus receives the fertilized ovum and helps to nourish the fetus throughout pregnancy.
• Labour: The muscles of the uterus contract to help S
• the expulsion of uterine content.
• Involution: The uterus returns to its normal size after childbirth. 

 Blood supply

• Uterine arteries branches of the internal iliac arteries supply blood to the uterus. Again it divides into branches and supplies blood to the cervix and upper vagina and then turns upward to supply the body of the uterus.
• Venous drainage: This is by the uterine and ovarian veins, which accompany the arteries.
  Lymphatic drainage: Lymph is drained from the uterine body to internal iliac glands mainly.
  Nerve supply: Mainly from the autonomic, sympathetic and parasympathetic nervous system via the pelvic plexus.