Presentation on theme: "Perineum General features Region of below pelvic diaphragm"— Presentation transcript:
1Perineum General features Region of below pelvic diaphragm A diamond-shape space whose boundaries are those of the pelvic outletLower border of symphysis pubisRami of pubis and ischiumIschial tuberositySacrotuberous ligamentTip of coccyx
2Perineum Two triangles The perineum is divided into anterior and posterior triangles by joining the ischial tuberosities with an imaginary lineUrogenital region (anterior)－differs in male and femaleAnal region (posterior) －similar in both sexes
3Anal region Anal sphincters Internal Smooth muscle (thickened circular muscle coat)Surrounds upper two-thirds of anal canalAutonomic nerve supplyExternalStriated muscleSurrounds lower two-thirds of anal canalThree parts－subcutaneous, superficial and deepInnervation by anal nerves of pudendal nerve and branches of S4
4Anal region Anorectal ring At junction of rectum and anal canal Consists of thickened muscleContributing structuresPuborectalisSuperficial and deep parts of sphincter ani externusSphincter ani internus
5Anal region Ischioanal fossa Paired, wedge-shaped, fat-filled spaces on either side of anal canalBoundariesApex－conjunctive area of inferior fascia of pelvic diaphragm and fascia covering the obturator internusBase－skin of anal regionMedially－sphincter ani externus, levator ani, coccygeus and inferior fascia of pelvic diaphragmLaterally－ischial tuberosity, obturator internus and fascia
6Anal region Ischioanal fossa Anteriorly Forward projection of anterior recess of fossa between pelvic diaphragm above and urogenital diaphragm belowPosteriorlyBackward projection of posterior recess of fossa between gluteus maximus, sacrotuberous ligament and coccygeus
7Anal region Ischioanal fossa Contents Fat Internal pudendal artery and vein and their rectal branchesPudendal nerve and its inferior rectal branchPudental canal (Alcock’s) －on the lateral wall of fossaPudendal n.Internal pudendal a. and v.
8Anal regionPudendal n.leaves the pelvis through the infrapiriform foramen and enters the gluteal region.Enters the perineum through the lesser sciatic foramen and then passes forward in the pudendal canal with the internal pudendal vessels.
10Urogenital region Superficial fascia The fatty layer The membranous layer － superficial fascia of perineum or Colles’ fasciaAttached posteriorly to the posterior border of the urogenital diaphragmLaterally to the margins of pubic arch and ischial tuberosityAnteriorly it is continuous with:Dartos of the scrotumFascia of the penisScarpa’s fascia
11Scarpa’s fasciaCamper’s fasciaLine of fusionPosition of penisFascia latersuperficial fascia of perineumPosition of scrotum
12Urogenital region Deep fascia Superior fascia of urogenital diaphragm Inferior fascia of urogenital diaphragmAttachedposteriorly to the posterior border of the urogenital diaphragmLaterally to pubic archIn front they fuse together forming the so-called: transverse perineal ligament
13Urogenital region Two spaces Deep perineal space Superficial perineal space
14Urogenital region Superior fascia of urogenital diaphragm Deep perineal spaceInferior fascia of urogenital diaphragmSuperficial perineal spaceScarpa’s fasciaSuperficial fascia of perineum(Colles’ fascia)Fascia of the penisDartos of the scrotum
15Urogenital region Superficial perineal space Lies between inferior fascia of urogenital diaphragm and superficial fascia of perineum.It is closed behind and laterally.
16Urogenital region Superficial perineal space Anteriorly, the space communicates with the potential space lying between the Scarpa’s fascia and the anterior abdominal muscles.In rupture of cavernous part of urethra, urine can extravasate from scrotum upward in front of symphysis pubis into anterior abdominal wall deep to Scarpa’s fascia
18Urogenital region Superficial perineal space Contents Posterior part－superficial transverse muscle of perineumLateral part－crus penis (male), crus of clitoris (female) and ischiocavernousus covering themCentral part－bulb of urethra (male), bulb of vestibule (female) and bulbocavernousus covering themBranches of pudendal nerves and internal pudendal vessels
19IschiocavernoususClitorisCrus of clitorisBulb of vestibuleGreat vestibular glandSuperficial transversem. of perineal
21Urogenital region Superficial perineal space Contents Posterior part－superficial transverse muscle of perineumLateral part－crus penis (male), crus of clitoris (female) and ischiocavernousus covering themCentral part－bulb of urethra (male), bulb of vestibule (female) and bulbocavernousus covering themBranches of pudendal nerves and internal pudendal vessels
22Urogenital region Deep perineal space The closed space that is contained between superior and inferior fascia of urogenital diaphragmContentsDeep transverse muscle of perineumBulbourethral gland (male)Sphincter of urethraArteries, veins and nerves
23Urogenital region Urogenital diaphragm Triangular in shape Formed by sphincter of urethra, deep transverse perineal muscle, superior and inferior fascia of urogenital diaphragm
24Perineal central tendon Wedge-shape fibromuscular massIn female, between anal canal and lower end of vaginaIn male, between anal canal and root of penisIt is larger in the female than in the male and fine support to the posterior wall of the vagina
25Perineal central tendon Sphincter ani externusLevator aniSuperficial transverse muscle of perineumDeep transverse muscles of perineumBulbocavernoususSphincter of urethra (male) or urethrovaginal sphincter (female)
26Perineal central tendon Sphincter of urethra (male) orurethrovaginal sphincter (female)BulbocavernoususDeep transverse muscles of perineumSphincter ani externusSuperficial transverse muscle of perineumLevator ani