Lecture 7 Female Genital System (External structures) PDF

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Gedrukte materiaal word eweneens slegs vir klasbespreking, private studie en navorsingsdoeleindes beskikbaar gestel. Die verdere reproduksie daarvan is ontoelaatbaar. 2 FEMALE EXTERNAL GENITALIA 3 1. Introduction to basic terminology Sex and Gender Clayton and Tannenbaum (2016) says the difference between ’sex’ – a biological category and ‘gender’- a category comprising the social, environmental, cultural, behavioral factors and choices that influence a person’s self-identity needs to be delineated so that students understand that biological sex may not correlate with the same person’s sense of their own gender. Slide by Ruan Lochner 2. Presentation of sex as a spectrum Microchimerism; Biological sex as a spectrum (Haig, Aintsworth & Fausto-Sterling; 2019, 2015 & 2000) Important not to create a “third sex” David's (2015) has described at least 25 intersex variations in his research and represents a continuum between male and female Slides by Ruan Lochner  Outcomes Describe the structures of the female external genitalia (vulva): mons pubis labia majora labia minora Clitoris vestibulum of the vagina the bulbs of the vestibule greater vestibular glands. Describe the nerve supply of female external genitalia. 6 EXTERNAL GENITALIA 7  Female External Genitalia/Vulva Located in the urogenital triangle in the perineum. Contains the female external genitalia: mons pubis, labia majora, labia minora, clitoris, vestibulum of the vagina, the bulbs of the vestibule, greater vestibular glands. Pudendum = clinically used word. BUT controversial: removed from Terminologia Anatomica in 2019 Latin root of the word: pudēre “to be ashamed”. 8  Female external genitalia Mons pubis Eminence anterior to pubic symphysis. Contains adipose tissue, covered by pubic hair after puberty. Continuous with the anterior abdominal wall. Labia majora Prominent folds of skin. External parts covered by pubic hair after puberty. Pass inferoposteriorly from the mons pubis towards anus. Round ligament terminates here. Join anteriorly to form the anterior commissure. Join posteriorly: posterior commissure (disappears after giving birth). https://www.youtube.com/watch?v=2Hip1OSbaqE&t=4s 9  Female external genitalia Pudendal cleft Area between the labia majora. Contain the labia minora and vestibule. Labia minora Inner folds of hairless skin. Surround the vestibule: opening into which the external urethral & vaginal orifices open. Spongy connective tissue with erectile tissue at their base, many blood vessels. Unite anteriorly to form the frenulum of the clitoris and the prepuce (foreskin) of the clitoris. Connected posteriorly by frenulum of labia minora (fourchette). May disappear when becoming sexually active. 10  Female external genitalia Clitoris Sexual arousal: composed of erectile tissue. Located where labia minora meet anteriorly. Consists of: Body: composed of two crura (attached to the inferior pubic ramis & perineal membrane) & two corpora cavernosa: covered by the prepuce. Glans: most innervated part, dense supply of sensory endings. 11  Female external genitalia Vestibule of vagina Space between labia minora. Contains orifices of the urethra and vagina. External urethral orifice: located 2-3 cm postero- inferior to the glans clitoris and anterior to the vaginal orifice. Ducts of lesser vestibular glands (also called Skene’s glands/para-urethral glands) open on each side of the external urethral orifice. Secretes mucous: moisten labia and vestibule. Ducts of the greater vestibular glands are located on medial aspects of labia minora. Hymen may be present covering the vaginal orifice: Thin fold of mucous membrane. Ruptures during sexual intercourse: remnants are called hymenal caruncles. Demarcate the vagina from the vestibule. 12  Female external genitalia Bulbs of vestibule Paired erectile tissue on either side of vaginal orifice. Deep to the labia minora, immediately inferior to the perineal membrane. Covered by the bulbospongiosus muscles. Homologous with the bulb of the penis. Small bands of erectile tissue connect the anterior ends of the bulbs of the vestibule to the glans clitoris. Greater vestibular glands (Bartholin glands) Located in the superficial perineal pouch/space. Lie on either side of the vestibule, posterolateral to the vaginal orifice and inferior to the perineal membrane. Partly covered by the bulb of the vestibule and the bulbospongiosus muscle. Ducts open into the vestibule on each side of the vaginal orifice. 13 Secrete mucous into the vestibule during sexual arousal. NERVE SUPPLY 14  Nerve supply of external genitalia Anterior aspect: mons pubis and anterior labia majora. Primarily by the  Anterior labial nerves from ilioinguinal pudendal nerve nerve and genital branch of genitofemoral nerve (lumbar plexus). Posterior aspect:  Lateral - perineal branch of posterior cutaneous nerve of thigh (sacral plexus).  Centrally – pudendal nerve: Labia - posterior labial nerves perineal nerve pudendal nerve. Orifice of vagina and superficial perineal muscles deep and muscular branches of perineal nerve. Sensation to clitoris and deep perineal muscles dorsal nerve of clitoris. 15  Pudendal Nerve Motor to muscles of perineum, sensory to majority of perineal region via its branches: 1. Inferior rectal nerve. 2. Perineal nerve: divides into superficial and deep branches. 3. Dorsal nerve of clitoris (penis in males). Pathway: https://www.facebook.com/watch/?v=228843159111200 16  Pudendal Canal Main arterial supply to the pudendum is the internal pudendal artery. Internal pudendal artery, vein and pudendal nerve run within the pudendal canal. Horizontal passageway within the obturator fascia covering the medial aspect of obturator internus muscle. Neurovascular bundle enters canal at the lesser sciatic notch, inferior to the ischial spine. Give off the inferior rectal artery and nerve: passes medially to supply external anal sphincter and surrounding skin. Towards distal end of canal, artery & nerve bifurcates: perineal nerve & artery – distributed to the superficial pouch; & dorsal artery and nerve of clitoris –runs in deep pouch (superior to perineal membrane). At dorsum of clitoris: nerve runs on lateral side on the continuation of the internal pudendal artery. 17 https://musculoskeletalkey.com/internal-pudendal-artery/  Nerve supply of external genitalia: Autonomic Parasympathetic fibers via cavernous nerves from uterovaginal plexus- Innervate erectile tissues (bulb of vestibule and body of clitoris). Parasympathetic stimulation: vaginal secretion, erection of clitoris, engorgement of erectile tissue in bulb of vestibule. 18 Pudendal nerve neuralgia/ block https://www.youtube.com/watch?v=HCjtaJFgv6E&list=PLvIhB9ywT9N tbIhOpySYZ_gWAdr3CoNJy&t=112s 19 THANK YOU FOR LISTENING 20