Lecture 10 Pelvic Diaphragm and Perineum PDF

 Copyright notice Material which is made available by way of an electronic database may be subject to certain licensing conditions. These conditions normally entail that you may only use the material for your own private study and research at the University and...

 Copyright notice Material which is made available by way of an electronic database may be subject to certain licensing conditions. These conditions normally entail that you may only use the material for your own private study and research at the University and not for any other purpose. It is expected of you to adhere to these conditions at all times. Printed material is also only made available for class discussion, private study and research purposes. Further reproduction of such material is prohibited /Materiaal wat by wyse van elektroniese databasis aan u beskikbaar gestel is, mag onderhewig wees aan bepaalde lisensievoorwaardes. Sulke voorwaardes behels normaalweg dat u die materiaal slegs vir u eie private studie en navorsing aan die Universiteit kan gebruik en vir geen ander doeleindes hoegenaamd nie. Daar word van u verwag om te alle tye aan hierdie voorwaardes gehoor te gee. Gedrukte materiaal word eweneens slegs vir klasbespreking, private studie en navorsingsdoeleindes beskikbaar gestel. Die verdere reproduksie daarvan is ontoelaatbaar.  Outcomes Revise the bony features of the pelvis including ligaments and joints. Discuss the muscles forming the pelvic diaphragm, including function & nerve supply. Define the perineum, urogenital triangle, anal triangle and perineal body. Name the borders of the perineum. Discuss the muscles of the perineum, including function & nerve supply. 3 Recommended resources https://www-clinicalkey- com.ez.sun.ac.za/#!/content/bo ok/3-s2.0- B9780323934237000046?scroll To=%23hl0004265 Primal Pictures 4 PELVIC DIAPHRAGM AND PERINEUM 5 PELVIS: OVERVIEW & REVISION 6  Pelvis: Overview Definition Bony of pelvis. components (os Boundaries of coxa and pelvic cavity: sacrum = pelvic girdle). Muscles of Features, joints walls and and floor. ligaments. Subdivisions: Greater pelvis Pelvic cavity and lesser pelvis. 7  Pelvic cavity Pelvis cavity is a space surrounded by the pelvic girdle Area of transition between the trunk & lower limbs Bony components of pelvic girdle: Right and left hip (innominate/pelvic) bones and sacrum Moore’s Clinically Oriented Anatomy, Wolters Kluwer Pelvic cavity subdivided by pelvic brim (pelvic inlet) into: Greater (false) pelvis (contains the inferior abdominal viscera) Lesser (true) pelvis includes pelvic cavity Pelvic cavity walls: antero-inferior, posterior, 2 lateral, floor Pelvic outlet – includes inferior pelvic aperture 8 PELVIC DIAPHRAGM 9  Pelvic wall: Muscles Lateral pelvic walls are covered by obturator internus muscles: Obturator fascia thickened to form tendinous arch Posterolateral wall contains piriformis muscle Pelvic floor is formed by: Pelvic diaphragm muscles (coccygeus and levator ani) Located in the pelvic outlet Attached to tendinous arch  Pelvic Floor: Pelvic diaphragm Formed by pelvic diaphragm muscles: Coccygeus and levator ani muscles Separates pelvic cavity from perineum Coccygeus: originates from lateral aspect of inferior sacrum & coccyx; attaches to sacrospinous ligament Levator ani: attached anteriorly to pubic bones, ischial spines posteriorly & tendinous arch laterally Like a hammock between the bones of the pelvis Moore’s Clinically Oriented Anatomy, Wolters Kluwer Anterior gap between medial borders: urogenital hiatus passage for urethra (& vagina in females) 11  Pelvic Diaphragm: Levator ani Levator ani is composed of 3 muscles: Puborectalis: runs from posterior pubis and forms a sling around rectum Forms boundary of urogenital hiatus Pubococcygeus: runs from posterior pubis & tendinous arch to coccyx, join in the midline to form anococcygeal ligament (extends from anus to coccyx) Lateral to puborectalis Moore’s Clinically Oriented Anatomy, Wolters Kluwer Gives off muscular slips to midline structures: puboprostaticus (males), Functions: supports pelvic viscera: pubovaginalis (females), puboanalis Maintains closure of rectum and vagina Iliococcygeus: runs from tendinous arch & ischial Puborectalis: maintains the perineal spine to anococcygeal ligament flexure (angle) – keeps rectum closed Most posterolateral of the three muscles (continence) supports posterior pelvic floor 12  Pelvic Diaphragm Muscles making up pelvic diaphragm? Muscles making up levator ani? Nerve supply: Levator ani: nerve to levator ani (S4); inferior rectal branch of pudendal nerve (S2-S4). Coccygeus: coccygeal plexus (S4-S5). 13 PERINEUM 14  Perineum Diamond-shaped region between the thighs, inferior to the pelvic floor Bounded by pelvic outlet and separated from pelvic cavity by pelvic diaphragm Contains anal canal, urethra, vagina (females) & external genitalia Borders: Anterior – pubic symphysis Anterolateral – inferior pubic rami and ischial rami Lateral – ischial tuberosities Moore’s Clinically Posterolateral – sacrotuberous ligaments Oriented Anatomy, Wolters Kluwer Posterior – sacrum and coccyx Divided into two triangles: by a line drawn between ischial tuberosities: Urogenital triangle: contains urethra & external genitalia Anal triangle: contains anus & external anal sphincter 15  Perineum Anterior part of pelvic outlet is closed by urogenital diaphragm, and posterior part by pelvic diaphragm 16  Urogenital triangle: Perineal membrane Urogenital hiatus – is the U shaped defect in anterior part of levator ani muscles “Filled in” by the perineal membrane: Thick fibrous sheet Free posterior border, anchored in posterior midline to perineal body, attached laterally to pubic arch 17  Urogenital triangle: Perineal body Perineal body: irregular mass containing collagen and elastic fibers, skeletal and smooth muscle Lies deep to skin, posterior to vaginal vestibule/ bulb of penis, anterior to anus and anal canal Anterior part blends with perineal membrane, superior part with rectovesical (males) or rectovaginal septum (females) Site of convergence of muscles: Bulbospongiosus External anal sphincter Superficial and deep transverse perineal Smooth & voluntary slips from external urethral sphincter, levator ani 18 Urogenital triangle: Perineal space Perineal membrane divides urogenital triangle into two pouches/spaces: Deep perineal space is superior (deep) to perineal membrane Contains skeletal muscle (external urethral sphincter, deep transverse perineal) & neurovascular tissues Pierced by urethra in male, urethra & vagina in female Superficial perineal space is below (superficial to) perineal membrane Contains the external genitalia & associated skeletal muscles (Superficial transverse perineal, bulbospongiosus, ischiocavernosus) 19  Superficial perineal space: Contents Bulb and crura of penis Clitoris and bulbs of the vestibule Proximal spongy urethra Greater vestibular glands Superficial transverse perineal muscles Superficial transverse perineal muscles Bulbospongiosus muscles Bulbospongiosus muscles Ischiocavernosus muscles Ischiocavernosus muscles Deep perineal vessels & dorsal nerve of penis Deep perineal vessels & dorsal nerve of clitoris 20  Perineal muscles: Function Perineal muscles: assists in urination in both sexes Ejaculation in males Strengthen pelvic floor/perineal body Assists & maintains erection of penis (males) and clitoris (females) Bulbospongiosus compresses bulb of penis to expel last drops of urine/semen More well developed in males Moore’s Clinically Oriented Anatomy, Wolters Kluwer 21  Nerve supply of perineal muscles Muscles of perineum: bulbospongiosus, ischiocavernosus, superficial and deep transverse perineal: deep branch of perineal nerve, branch of pudendal nerve (S2, S3, S4). External urethral sphincter: dorsal nerve of penis or clitoris (terminal branch of pudendal nerve, S2, S3, S4). External anal sphincter by inferior rectal nerve (branch of pudendal nerve, S2, S3, S4). 22 Nerve supply of perineal muscles 23  Urogenital diaphragm Urogenital diaphragm consists of: The deep perineal muscles: Paired deep transverse perinea External urethral sphincter AND Fascial coverings: The inferior fascia –perineal membrane Superior fascia (continuous with pelvic fascia) Urogenital diaphragm 24 Male and Female Perineum: Surface Anatomy 25 Urogenital diaphragm = 26 RECAP 27 THANK YOU FOR LISTENING! 28