Lecture Notes - Male Reproductive Anatomy

Bony Structure

• 2 hip bones: ilium, pubis, ischium
• 1 sacrum
• 1 coccyx

Ligaments - hold/bind bony pelvis together and hold pelvis in proper orientation to resist forces
• sacrotuberous
• sacrospinous
• sacroiliac
Orientation - NOT a basin!!! Tilt to ~80° angle
• Pubic tubercles and ASIS in vertical line

Peritoneum

Falls short - does not reach pelvic floor/diaphragm
• Pouches
  • Female - vesicouterine & rectouterine
  • Male - rectovesical
• Broad Ligament - mesosalpinx, mesovarium, & mesometrium

Viscera

Rectum
• peritoneal covering - top 1/3 on front and sides, middle 1/3 on front, inferior 1/3 none
• transverse rectal folds
• passes through pelvic diaphragm to become anal canal
• blood supply and venous return - portocaval anastomosis
Anal Canal
• internal anal sphincter - thickened circular (smooth) muscle
• external anal sphincter - skeletal muscle
• anal columns, valves, and sinuses - what forms columns?
  • Pectinate Line - functional significance??
Reproductive Organs
• Female:
  • Uterus
    • fundus, body, isthmus, cervix (internal and external os)
    • round ligament (anterior)
    • uterine artery OVER ureter
    • anteverted vs. anteflexed
  • Uterine Tube
    • isthmus, ampulla, infundibulum, fimbriae
  • Ovary
    • suspensory ligament (contains ovarian vessels)
    • proper ovarian ligament
    • (ovarian + round ligaments = gubernaculum)
  • Vagina
    • from cervix to vestibule
    • vaginal fornices - recess around cervix (anterior, posterior, lateral)
• Male:
  • Testis
    • seminiferous tubules
    • epididymis - head, body, tail
  • Spermatic Cord
    • ductus deferens
    • testicular artery
    • pampiniform plexus of veins
  • Ejaculatory Ducts
    • ampulla of ductus deferens + seminal vesicles
    • through prostate to join urethra at seminal colliculus
  • Prostate
    • base of bladder
    • median lobe = uvula
Bladder
• apex, fundus, body, neck
• trigone = ureteric orifices + internal urethral orifice
• urethra
  • male: prostatic, membranous, penile (spongy)
  • female: membranous
Perineum - inferior to pelvic diaphragm
• Anal Triangle
  • ischioanal fossae - lateral to anal canal
    • obturator internus muscle is lateral wall
  • pudendal canal - fascia of obturator internus muscle
    • contains internal pudendal vessels & pudendal nerve
  • anal canal - review anal canal - internal structures and sphincter muscles
• Urogenital Triangle
  • Perineal Membrane - bands of connective tissue between midline viscera and ischiopubic rami; erectile tissues attached to caudal surface

Female	Male
2 corpora cavernosa shaft of clitoris diverge as 2 crura along ischiopubic rami crura covered by ischiocavernosus muscle	2 corpora cavernosa shaft of penis diverges as 2 crura crura covered by ischiocavernosus m.
2 bulbs of the vestibule glans of clitoris covered by bulbospongiosus m. greater vestibular glands	1 corpus spongiosus glans of penis spongy urethra bulb covered by bulbospongiosus m.
perineal body muscle fibers from: bulbospongiosus, external anal sphincter & superficial transverse perineal	central tendinous point mm. fibers from: bulbospongiosus, ext. anal sphincter & superficial transverse perineal
sphincter urethrae (urethrovaginal sphincter & compressor urethrae)	sphincter urethrae bulbourethral glands



Pudendal Nerve
• motor to all perineal muscles and sensory to most perineal structures
• 3 branches
  • inferior rectal - external anal sphincter and skin around anus
  • perineal - posterior labial/scrotal branches
  • dorsal nerve of clitoris/penis - remainder of pudendal; within connective tissue of perineal membrane; pierces membrane at anterior border and runs with dorsal aa. and v.
Internal Pudendal Artery
• 3 branches
  • inferior rectal - anastomoses with which vessels?
  • perineal - superficial; terminates as posterior labial/scrotal
  • internal pudendal - runs deep with dorsal n. of clitoris/penis
    • 2 terminal branches
      • deep artery of clitoris/penis - within corpora cavernosa
      • dorsal artery of clitoris/penis - with nerves and vein
Vessels
• Common Iliacs
  • External Iliacs - vessel of lower limb
  • Internal Iliacs - pelvis, gluteals, medial thigh, perineum
• Internal Iliac - highly variable!!
  • posterior division - parietal branches only
    • iliolumbar
    • lateral sacral
    • superior gluteal
  • anterior division - parietal and visceral branches
    • inferior gluteal
    • obturator (30% aberrant)
    • internal pudendal (around sacrospinous ligament)
    • umbilical (1st branch off anterior division)
    • superior vesical (artery of the ductus deferens)
    • middle rectal
    • inferior vesical (prostatic branches)
    • uterine (relationship to ureter!!)
    • vaginal
Innervation
• Sacral Plexus
  • ventral primary rami of L4,5 (aka, lumbosacral trunk) and S1,2,3,4
  • relationship to piriformis muscle
• Autonomics
  • Inferior hypogastric plexus (sides of rectum) - continuation of preaortic plexus via hypogastric nerves
  • Sacral splanchnics - sympathetic fibers from sacral portion of sympathetic chain
  • Pelvic splanchnics - parasympathetic fibers from S2,3,4
Review Intro to Autonomics Module - this is the time to make it all come together!
Also, review the formation of the inferior hypogastric plexus (Pelvic Autonomics Module)
• where do sympathetics come from?
• where do parasympathetics come from?
• how are specific pelvic viscera innervated?
Pelvic Diaphragm/Floor
• Wall of Pelvic Cavity
  • Obturator Internus m.
    • Arcus Tendineus Levator Ani - attachment for portion of levator ani m.
  • Piriformis m. - exits pelvis via greater sciatic foramen, sacral plexus lays on piriformis
• Floor or Diaphragm
  • Above = pelvic cavity
  • Below = perineum
    • Coccygeus m. - on internal surface of sacrospinous ligament
    • Levator Ani m.
      • pubococcygeus
      • iliococcygeus
      • puborectalis
      • genital hiatus