Perinuem, Male & Female Genitalia Anatomy Notes PDF

Perineum, Male and Female Genitalia  Perineum o Most inferior portion of trunk o Inferior to pelvic diaphragm o Angles (as viewed I -> S)  Anterior  Inferior border of pubic sym...

Perineum, Male and Female Genitalia  Perineum o Most inferior portion of trunk o Inferior to pelvic diaphragm o Angles (as viewed I -> S)  Anterior  Inferior border of pubic symphysis  Posterior  Apex of coccyx  Lateral  Ischial tuberosities o Borders  Anterolateral  Ischiopubic ramus  Posterolateral  Sacrotuberous lig. o Regions  Posterior  Anal triangle  Contains anal canal in midline & Ischioanal (ischiorectal) fossa  On each side of anal canal  Anterior  Urogenital triangle  Ischioanal fossa o Walls  Inferior wall  Skin  Superomedial wall  Levator ani m.  External anal sphincter m.  Lateral wall  Lower part of obturator internus m.  Ischial tuberosity o Extends into urogenital triangle o Contents  Large amounts of fat  Pudendal n. & internal pudendal vessels  Along lateral wall in pudendal (Alcock's) canal  Inferior rectal n. & vessels  Branch of pudendal n. & internal pudendal vessels  Nerve supplies:  external anal sphincter, mucosa of lower anal canal, & perianal skin  Urogenital triangle o Attached to each side of ischiopubic ramus o Anterior border separated from pubic symphysis by deep dorsal vein (of penis/clitoris)  o Perforated by  Urethra & either bulbourethral ducts or vagina (male vs. female)  Branches of internal pudendal vessels  Dorsal n. (of penis/ clitoris)  Branch of pudendal n. o Superficial fascia divided into  Membranous layer  Colles' fascia (superficial perineal fascia)  Attaches posterior to posterior perineal membrane  Attaches lateral to ischiopubic rami  Fatty layer o Superficial perineal pouch  b/w Colles' fascia & perineal membrane o Deep perineal pouch  Inferior border is perineal membrane  Superior border is inferior fascia of pelvic diaphragm  Perineal body o Converging spot of muscles include:  Bulbospongiosus m.  External anal sphincter m.  Levator ani m.  Superficial transverse perineal m.  Deep transverse perineal m.  Male genitalia o Spermatic cord  Location  Begins at deep inguinal ring  Through inguinal canal  Exits through superficial inguinal ring  Components  Vas deferens  Testicular a. & v.  Artery of ductus deferens  Cremasteric a.  Lymph vessels  Autonomic nn.  Genital branch of genitofemoral n.  Testicular lymph drains into para-aortic lymph nodes  Scrotum lymph drains into superficial inguinal lymph nodes o Testis  Function  Produce spermatozoa via spermatogenesis  Need to be 1-3oC cooler than abdominal temp  Production of testosterone  Surrounded by tunica albuginea  Interior  Divided into lobules via fibrous septa  Each lobule contains 1-3 seminiferous tubules   Open into rete testis  Efferent ductules connect rete testis to epididymis o Epididymis  Storage & maturation of spermatozoa  Parts  Head  Body  Tail (continuous w/ vas deferens) o Scrotum  Layers  Skin  Tunica dartos  Derived from superficial fascia of anterior abdominal wall  Contains dartos m. (smooth m.)  External spermatic fascia  Derived from aponeurosis of external oblique m.  Cremaster m. & fascia  Derived from internal oblique m.  Internal spermatic fascia  Derived from transversalis fascia  Tunica vaginalis  Derived from peritoneum  Lower expanded part of processus vaginalis  Visceral layer  Covers testis & epididymis  Parietal layer  Covers inner aspect of internal spermatic fascia  Has potential space b/w the 2 layers  Allows testis to move freely in scrotum  Hydrocele  Abnormal fluid accumulation in this space  There are no layers derived from transversus abdominis m. o Penis  Parts  Body  Proximal part connected to pubic symphysis via suspensory lig.  2 corpora cavernosa  1 corpus spongiosum  Glans penis  Prepuce (foreskin)  Root  Within superficial perineal pouch  Inferior to perineal membrane  Formed via  Posterior ends of corpora cavernosa   Aka crura of penis  Attached to ischiopubic rami  Posterior end of corpora spongiosum  Aka bulb of penis  Attached to perineal membrane b/w crura o Superficial perineal muscles  All innervated by perineal branch of pudendal n.  Bulbospongiosus m.  Covers bulb of penis  Helps empty urethra  Ischiocavernosus m.  Covers crus of penis  Helps maintain erection  Superficial transverse perineal m.  Fixes perineal body to pelvic floor o Superficial perineal pouch  Contents  Superficial perineal mm.  Perineal n. & vessels  Crura of penis  Bulb of penis o Deep perineal pouch  Contents  Deep transverse perineal mm.  Sphincter urethrae m.  Aka External urethral sphincter m.  Membranous urethra  Bulbourethral gland  Aka Cowper's gland  Lubrication & pre-ejaculate part  Dorsal n. of penis  Internal pudendal vessels  Female genitalia o Vulva  Collective parts of genitalia  Mons pubis  Labia majora  Space b/w called pudendal cleft  Labia minora  Space b/w called vestibule of vagina  Clitoris  Homologue of penis in female  Corpora cavernosa  2 erectile bodies  Crura of clitoris  Posterior part of corpora cavernosa  Body of clitoris   Midline union of corpora cavernosa  Proximal part connected to pubic symphysis  Via suspensory lig. of clitoris  Bulbs of vestibule  Erectile tissue along labia minora  Homologue of bulb of penis  Covered by bulbospongiosus m.  Become enlarged w/ clitoris during sexual excitation  Greater vestibular glands  Posterior ends of bulbs of vestibule  Homologue of bulbourethral glands  Secretes mucus that lubricates vulva o Paraurethral glands  Aka Skene's glands  Homologue of prostate  Closer to lower end of urethra, mucous glands o Superficial perineal pouch  Contents  Superficial perineal mm.  Perineal n. & vessels  Crura of clitoris  Bulbs of vestibule  Greater vestibular glands o Deep perineal pouch  Contents  Deep transverse perineal mm.  Sphincter urethrae m.  Aka External urethral sphincter m.  Sphincter urethrovaginalis m.  Compressor urethrae m.  Part of urethra  Part of vagina  Dorsal n. of clitoris  Internal pudendal vessels  Pudendal n. o Branch of sacral plexus  Ventral rami S2-S4 o Leaves pelvis via greater sciatic foramen, inferior to piriformis, posterior to ischial spine o Enter perineum via lesser sciatic foramen o Travels anterior in pudendal canal along lateral wall of ischioanal fossa o Branches as it gets to urogenital triangle  Perineal n.  All m. within urogenital triangle (superficial & deep)  Gives off posterior scrotal/ labial branches  Within superficial perineal pouch  Dorsal n. of penis/ clitoris  Starts within deep perineal pouch   Pierces perineal membrane -> glans of penis/ clitoris  Inferior rectal n.  Internal pudendal a. o Travels w/ pudendal n. o Branches  Inferior rectal a.  Perineal a.  Superficial urogenital triangle structures  Posterior scrotal/labial aa.  Terminal branches  Deep a. of penis/ clitoris  Pierces perineal membrane -> crus of penis/ clitoris  Supplies erectile tissue  Dorsal a. of penis/ clitoris  Pierces perineal membrane -> glans of penis/ clitoris