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External genitalia.pptx

  2. Introduction • The reproductive organ in female are those which concerned with copulation, fertilization, growth and development of fetus and its subsequent exit to the outer world. • The female reproductive organs can be subdivided into • a) External genitalia • b) Internal genitalia • c) Accessory reproductive organs.
  3. Functions of female reproductive system • The female reproductive system is designed to carry out several functions. It produces the female egg cells necessary for reproduction, called the ova or oocytes. The system is designed to transport the ova to the site of fertilization. • Fertilization of an egg by a sperm, normally occurs in the fallopian tubes. The next step for the fertilized egg is to implant into the walls of the uterus, beginning the initial stages of pregnancy. • If fertilization and/or implantation does not take place, the system is designed to menstruate . • In addition, the female reproductive system produces female sex hormones that maintain the reproductive cycle.
  4. External genitalia or vulva • Parts that are outwardly visible are called vulva. Externat genitalia is also known as pudendum. • The vulva includes: • Mons pubis • Labia majora • Labia minora • Clitoris • Vestibule • Urethral opening • Vaginal opening • Greater vestibular glands/ Bartholin glands • Perineum There are individual differences in • Size • Coloration • Shape
  6. Functions of vulva • The vulva (pudendum) refers to the external female genitalia. Its functions are: • Assists in micturition by directing the flow of urine • Protects the internal female reproductive tract from infection. • Acts as sensory tissue during sexual intercourse
  7. Structures of the Vulva Vulva is a collective term for several anatomical structures: • Mons pubis • Labia majora • Labia minora • Clitoris • Vestibule • Bartholin’s glands / • Perineum
  8. Mons pubis • The rounded pad of subcutaneous fat located anterior to the pubic symphysis. • It protects the pubic symphysis. • During adolescence sex hormones trigger the growth of pubic hair on the mons pubis • Hair varies in coarseness curliness, amount, color and thickness
  9. Labia majora • Labia majora are two hair-bearing thick fold of skin, fibrous tissues and fat. They are also referred as outer lips of vulva. They form the lateral boundaries of pudendal cleft. • Their outer surfaces are covered with hair, the inner surfaces have large sebaceous glands • Anteriorly the folds join in front of the symphysis pubis to each other below the mons pubis to form the anterior commissure. • Posterior ends of the labia are less prominent and merge with the skin, known as the posterior commissure. • The area between posterior commissure and the anus which is about 2.5 cm constitutes perineum.
  10. Labia minora • Labia minora are two hairless folds of skin, which lie within the labia majora. • They fuse anteriorly to form the hood of the clitoris and extend posteriorly either side of the vaginal opening. • Anteriorly, each labium minora splits into two layers, the upper layer joins the corresponding layer of the opposite side, to form the prepuce / hood of the clitoris. Similarly, the lower layers of the two sides join to form frenulum of the clitoris. • Posteriorly, the two labia minora merge posteriorly, creating a fold of skin known as the fourchette. • The inner surface of the labia minora contains numerous sebaceous glands.
  11. Clitoris • Highly sensitive organ composed of nerves, blood vessels, and erectile tissue. • It is formed of erectile corpora cavernosa tissue, which becomes engorged with blood during sexual stimulation. It plays a role in sexual pleasure for most women, but has no reproductive significance. • It is homologous to penis in males.
  12. Vestibule • The cleft between the labia minora is known as vestibule. Urethra, vagina, and ducts of the greater vestibular glands open into the vestibule. • Urethral orifice lies most anteriorly about 2.5 cm below the clitoris and in front of the vaginal orifice. • Vaginal orifice or introitus lies in the posterior part of the vestibule and is partly closed in the virgin by a thin membrane called the hymen. • Openings of the ducts of greater vestibular glands lie one on each side of vaginal orifice.
  13. Bartholin’s glands / greater vestibular glands • The greater vestibular glands (Bartholin’s glands) are pea sized glands, situated one on each side near the vaginal opening. They are about the size of a small pea and have ducts, opening into the vestibule immediately lateral to the attachment of the hymen and labia minora. • These glands secrete mucus that keeps the vulva moist.
  14. Perineum • It is roughly triangular area located between the vaginal opening and anal opening. • It consists of connective tissue, muscles and fat. • It gives attachment to the muscles of the pelvic floor. • It supports and surrounds the lower parts of the urinary and digestive tracts. • The perinium also contain an abundance of nerve endings that make it sensitive to touch. • An episiotomy is an incision of the perinium used during childbirth for widening the vaginal opening.
  15. Blood supply, lymph drainage and nerve supply • Arterial supply This is by branches from the internal pudendal arteries that branch from the internal iliac arteries and by external pudendal arteries that branch from the femoral arteries. • Venous drainage This forms a large plexus which eventually drains into the internal iliac veins. • Lymph drainage This is through the superficial inguinal nodes. • Nerve supply This is by branches from pudendal nerves.
  16. Vagina Vagina is a fibromuscular canal / tube that connects external and internal genitalia of the female. It runs obliquely upwards and backwards from vaginal orifice to cervix at an angle of about 45° between the bladder in front and rectum and anus behind. Direction: In the erect posture, the vagina is directed upwards and backwards. Long axis of uterus and cervix forms an angle of 90° with long axis of vagina. Relationship: • The vagina is closely related to many of the organs in the pelvic region: • Anterior - bladder and urethra. • Posterior – rectouterine pouch, rectum and anal canal. • Lateral – ureters and levator ani muscle.
  17. Contd… Size and shape: The anterior wall of the vagina is about 7.5 cm long and the posterior wall about 9 cm long. The difference is due to the angle of insertion of the cervix through the anterior wall. The diameter of the vagina gradually increases from below upwards. The upper end or vault is roughly 5 cm, twice the size of the lower end (2.5 cm). In the virgins, the lower end of the vagina is partially closed by a thin annular fold of mucous membrane called the hymen. In married women, the hymen is torn and represented by rounded elevations around the vaginal orifice, the caruncular hymenales. The shape of the vagina is not a round tunnel. In the transverse plane it is more like an “H” lying on the side. Because anterior and posterior walls – these are normally collapsed and thus in contact with one another.
  18. Standing and lying down posture
  19. Contd… Fornices of vagina: The interior of the upper end of the vagina or vaginal vault is in the form of a circular groove that surrounds the protruding cervix. The groove is divided into four parts called the vaginal fornices. The anterior fornix lies in front of the cervix and is the shallowest. The posterior fornix lies behind the cervix and is the deepest. Lateral fornices are one on each side of cervix. Posterior fornix is important as it acts like a natural reservoir for semen after intravaginal ejaculation. The semen retained in the fornix liquefies in the next 20-30 mins, allowing for easier permeation through the cervical canal.
  20. Histology of the Vagina Vagina is composed of four histological layers (internal to external): • Stratified squamous epithelium- innermost layer, this layer provides protection and is lubricated by cervical mucus from Bartholin glands(the vagina itself does not contain any glands). • Elastic lamina propria - a dense connective tissue layer which projects papillae into the overlying epithelium. The larger veins are located here. • Fibromuscular layer - comprising two layers of smooth muscle, an inner circular and an outer longitudinal layer. • Adventitia - a fibrous layer, which provides additional strength to the vagina whilst also binding it to surrounding structures.
  21. Vascular Supply and Lymphatics • Arterial supply: The arterial supply to the vagina is via the uterine and vaginal arteries – both branches of the internal iliac artery. • Venous drainage: Venous return is by the vaginal venous plexus, which drains into the internal iliac veins via the uterine vein. • Lymphatic drainage: Lymphatic drainage is divided into three sections: Superior – drains to external iliac nodes Middle – drains to internal iliac nodes Inferior – drains to superficial inguinal lymph nodes.22)
  22. Nerve supply • Nerve Supply --The lower one-third of the vagina is pain sensitive and is supplied by deep perineal nerve, a branch of the pudendal nerve. The upper two-thirds of the vagina are pain insensitive and are supplied by sympathetic L1, 2 and parasympathetic segments S2 to S4.
  23. Functions of vagina • Sexual intercourse – receives the penis and ejaculate, assisting in its transport of sperm to the uterus. • Childbirth – expands to provide a channel for delivery of a newborn from the uterus. • Menstruation – serves as a passage / canal for menstrual fluid and tissues to leave the body.