THE UTERINE (FALLOPIAN) TUBES

• These are two muscular tubes which are about 10cm long.

• They extend from the uterine cornu outward and laterally towards the ovaries.
• The lumen of the tube communicates with the uterine cavity and opens into the free peritoneal cavity.

Anatomical relation of the fallopian tube

• Anterior, posterior and superior: The peritoneal cavity and the intestinal.
• Lateral: Sidewalls of the pelvis
• Inferior: Broad ligaments and ovaries lie below the tubes.
• Medial: The uterus lies between fallopian tubes.
• Support: Fallopian tubes are held in place by their attachment to the uterus.

Parts of the fallopian tube

They are:-

The fallopian tubes have four parts from medial to lateral.

• The interstitial (Intramural): This is the narrowest part of the tube and measures 1.5cm in length and 1mm in diameter which lies in the uterine wall.

• The ampulla: This is the widest part where fertilization usually takes place. It measures about 5cm long and 6mm wide lumen and tortuous.
• The infundibulum: This is about an I cm funnel-shaped extremely made up of about 25 irregular figures-like structures called fimbriae. The longest one of the fimbriae called ovarianfimbriae lies in contact with the ovary to take the ovum into the tube after ovulation.

Structure of the uterine tube 

It consists of three layers:-

• The outer layer is a serious layer. It consists of a peritoneum on all sides except along the line of attachment of mesosalpinx. The peritoneum covers the superior, anterior and posterior surfaces of the tubes, but not the inferior surfaces.
• The middle layer is a muscular layer arranged in two layers outer longitudinal and inner circular. The circular fibres are best developed in the isthmus (0.5mm) and are thinned out near the fimbriated end (0.1mm) deep to the circular fibres; internal longitudinal fibre appears in some parts of the tube.
  The inner layer is a mucous membrane, which is lined by columnar epithelium, partly ciliated, which is thrown into a longitudinal fold, which almost obliterates 
• the lumen of the tube. Tubal secretion is a serous transudate containing proteins, sodium, bicarbonate, lactate pyruvate, and trypsin inhibitor. This is controlled by ovarian hormones. During embryo transport to the uterus, the secretion flows towards the uterus.

Blood supply

Arterial supply is from the uterine and ovarian. Venous drainage is through the pampiniform plexus into the ovarian veins.

Lymphatic drainage: The lymphatic runs along the ovarian vessels to para-aortic nodes.

Nerve supply: The nerve is derived from the uterine and ovarian nerves. The tube is very sensitive to handling.

Functions of the uterine tubes

•  It pushes or transports the ovum from the ovary to the uterine cavity by its muscular and ciliary action. The ovum itself has no power of movement.

• It receives spermatozoa for fertilization.
• It provides a site for fertilization at the ampulla (In the ampulla sperm and ovum meet within 5 to 10 minutes of ejaculation by coitus.)
• It supplies nutrition to the fertilized ovum during as travel to the uterus.
• Tubal secretion forms a medium for the capacitation of sperm and maturation of the morula.

THE OVARIES

• The ovaries are paired sex glands or gonads in females.
• It is an almond-shaped organ situated on each side of the uterus on the posterior surface of the broad ligament just below the pelvic brim and near the infundibulum.
• It is an intraperitoneal gland
• It measures approximately 4cm long, 3cm wide and 2cm thick in size and weight 5-10gm (average gm)
• during the reproductive period.

Structure of the ovary

The ovary consists of an inner zone called the 'medulla' and the outer 'cortex'. Which merge together and are not clearly defined. The ovary is covered by a single layer of cubical cells known as germinal epithelium.

It is attached to the posterior layer of broad ligaments by mesovarian and is suspended from uterine cornua by ovarian ligament.

It consists of :

• cortex
• medulla
• hilum

Cortex

It consists of stromal cells, which are thickened beneath the germinal epithelium to form tunica albuginea. It is an important, functioning part of the ovary.

At birth,, each ovary contains 2, 00,000 to 7, 00,000 primordial follicles which consist of a primitive ovum, 18-24 microns in diameter, surrounded by flattened epithelial cells. Only 400 primordial follicles will mature at the age of puberty. After puberty,, one ovarian follicle matures each month. The mature follicles are known as Graafian follicles and each follicle contains an ovum.

The cortex is composed of highly cellular spindle-shaped cells supporting ovarian follicles except at the hilum. The gryphon follicles are oestrogen-progesterone and ovum-producing functional units that lie scattered in the cortex.

All forms of agrarian follicles at different stages can be

seen as:

1. Primordial follicles: Newborn ovaries contain about
   2 million primordial follicles. At puberty,, 40,000 primordial follicles remain in ovaries and the rest undergo atresia. Around 400 follicles ovulate in 30 years of a woman's reproductive life from puberty to menopause.
2. Primary follicles: Twenty in number grow in a menstrual cycle from primordial follicles in both ovaries. In the primary follicle, a coat of polysaccharides develops around the primary oocyte called zona pellucida.
   Granulosa cells proliferate around zona pellucida to form ovarian follicles. Around proliferating granulosa, the cell layer develops a layer of vascular stromal layer called theca interna
3. Secondary follicle: Develops with proliferated granulose cell mass around oocyte and formation of fluid-filled spaces antrum follicle. The ovarian follicle with antrum is called the Graafian follicle.
4. Tertiary follicle: A single dominant follicle grows to
   16.25 mm in size. The tertiary follicle contains:

1. A mature secondary oocyte is called the ovum.
2. A mass of granulose cells that grow around the ovum is called discus proligerus.
   Granulosa cells lying close to the ovum are arranged in a radial fashion called corona radiata. Discus proliferous remain at one side of the antrum.
3. The wall of the antrum is formed by layers of granulose cells - Membrane granulose.
4. Theca Interna - a vascular layer of ovarian stroma surrounding the cystic follicle and fibrous theca external layer around theca interna.

Medulla

It consists of loose connective tissue, a few unstripped muscles, blood vessels and nerves. There are small collections of cells called, Hilus cells, which are homologous to the interstitial cells of the testes.

Granulosa cells in maturing Graafian follicles develop receptors of follicle-stimulating hormone (FSH) of the anterior pituitary gland. FSH hormone causes the proliferation of granulose cells in the ovarian follicles. The dominant follicle discharges the ovum (ovulation) on the ovarial surface. Ovum is picked up by tubal fimbria and it gets fertilized by sperm at tubal ampulla. Oestrogen is secreted by the Graafian follicle.

Corpus Luteum is formed out of the shell of a ruptured Grafian.

Follicle. The Corpus Luteum matures on the 9th day and retains its maturity for 26 days. It measures 1-2 cm and secretes progesterone. The normal functional life of the corpus luteum is 12-14 days. If pregnancy does not occur, the corpus luteum regresses on the 27th or 28th day with falling progesterone and estradiol levels in the blood. The Corpus luteum finally degenerates to form a hyaline mass called corpus albicans in the ovarian cortex. The ovum gets disintegrated in the fallopian tube within 24-48 hours if unfertilized. In pregnancy, the corpus luteum is maintained as the corpus luteum of pregnancy.

Functions of Ovary

• During the reproductive period, the ovary discharges the mature ovum at each menstrual cycle.
• Produces sex hormones - oestrogens and progesterone to prepare uterine endometrium for the embedding of the fertilized ovum.

C. ACCESSORY REPRODUCTIVE ORGANS

The Breasts

• The breasts are paired mammary glands between the second and sixth ribs.
• About two-thirds of the breast overlies the pectoralis major muscle between the sternum and midaxillary line, with an extension to the axilla referred to as the tail of Spence.
• The lower one-third of the breast overlies the serratus anterior muscle. The breasts are attached to the muscles by connective tissue or facia.
• Each mammary gland is made of 15 to 20 lobes divided into lobules.
• Lobules are clusters of acini. An acinus is a saline terminal part of a component gland emptying through a narrow lumen or duct.
• The acini are lined with epithelial cells that secrete colostrum and milk.
• Just below the epithelium is the myo- epithelium (myo, or muscle). Which contracts to expel milk from the acini.
• The duct from the clusters of acini that form the lobules merge to form larger ducts draining the lobules.
• Ducts from the lobules converge in a single nipple (papilla) surrounded by an areola.
• Just as the ducts converge they dilate to form common lactiferous sinuses, which are also called ampullae.
• The lactiferous ducts drain the ampullae and exit in the nipple.

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• The glandular structures and ducts are surrounded by protective fatty tissue and separated and supported by fibrous suspensory Cooper's ligaments.
• Cooper's ligaments provide support to the mammary glands while allowing mobility on the chest wall.
• The round nipple is usually slightly elevated above the breast. On each breast the nipple projects slightly upward and laterally. It contains 15 to 20 openings from lactiferous ducts.

Structure

The breast consists of the following tissues-

• Glandular tissue

• Each breast consists of about 15 to 20 primary lactiferous lobes which spread radially from the nipple.
  Below the nipple, each primary lactiferous duct expands to form a lactiferous ampulla or sinus.
• 20 - 40 secondary lactiferous ducts branch from each primary duct.
• 10 - 100 alveoli (acini cell) arise from each secondary alveolar duct, which produces milk and are surrounded by myoepithelial cells, which contract and propel the milk out.

* Fibrous tissue

• This encloses the glandular tissue and forms the supporting suspensory ligaments. It is made up of fibro-connective tissue.

* The fatty or adipose tissue

• This covers the surface of the gland and is found between the lobes.
• Glandular tissue is a small part but fat forms the bulk of the breast so the amount of tissue determines the size of the breast. Bands of fibrous tissue extend from the skin to the axillary tail of the mammary gland and extend upward and outward in the axilla.

Blood Supply

* Arterial Supply

• Lateral thoracic artery branch of the axillary artery.
• Internal mammary artery.
• Intercostal arteries

* Venous Drainage

• The veins are arranged in a circular fashion around the nipple, which in turn drains into the axillary, internal thoracic and intercoastal veins.

* Lymph Drainage

• Lymph drains freely between two breasts and into lymph nodes in the axillae and the mediastinum.

• Nerve Supply
• The nerve supply is from the fourth, fifth and sixth intercostal nerves.
• The breast tissue contains numerous free and encapsulated nerve endings, particularly around the nipple.

PELVIC FLOOR

Soft tissues that fill the outlet of the pelvis are called the pelvic floor. Through it passes the urethra, vagina and anal canal.

The pelvic floor is mainly made up of muscular tissue but skin, fat, fascia and connective tissue form this structure which fills in the irregular-shaped pelvic outlet.

Muscles of the pelvic floor consist of :

1. Superficial muscles,
2. Deep muscles.

Superficial Muscles

The superficial layer is composed of five muscles :

• The external anal sphincter surrounds the anus.
• The Transverse perineal muscles pass from the ischial tuberosities to the centre of the perineum.
• The bulb's cavernous muscles pass from the perineum forward around the vagina.
• Ischio cavernous muscles pass from ischial tuberosities along the pubic arch.
• The membraneous sphincter of the urethra is composed of muscle fibres passing above and below the urethra and attached to the pubic bones.

Deep Muscles

These are three pairs of muscles which together are known as the levator Ani muscles.

Each levator ani muscle consists of the following :

• The pubococcygeus muscle
• The iliococcygeus muscle
• The Ischio coccygeus muscle

The levator ani muscle, by its mode of attachment to the pelvis, acts like a sting or hammock. In front, they are attached to the lateral part of the os pubis, behind to the ischial spines and coccyx and laterally to the fascia. The three levator ani muscles meet to form a gutter which slopes forward and is perforated by three canals, i.e. urethra, vagina and rectum.

Functions of Pelvic Floor

•  The pelvic floor supports the weight of the abdominal and pelvic organs.
• Its muscles are responsible for voluntary control of micturition and defecation.
• Play an important part in sexual intercourse.
• During childbirth, it influences the passive movements of the foetus through the birth canal and relaxes to allow its exit from the pelvis.