Written Examination Part IV. (36 pts) - Essay: Abdomen, Pelvis, and Perneum (September 21, 2006)

Note: This is an outline of topics to be covered. It is not the "answer key." It is an answer guide.

Ischiorectal Fossa

Discuss the boundaries and contents of the ischiorectal fossa, fascial specializations, vascularization, innervation, lymphatic drainage, the relationship of the ischiorectal fossa to the superficial and deep pouches, and provide an explanation of your observation that urine does not accumulate in the superficial pouch. (12 pts)
  • General
    • Wedge shaped area located between the ischial tuberosites and the anorectal canal and consisting of a posterior recess and an anterior superior recess.
  • Boundaries of Anterior Superior Recess
    • Superior - inferior fascia of the pelvic diaphragm, most lateral and superior is arcus tendineous
    • Inferior - superior fascia of the urogenital diaphragm
    • Anterior - fusion of superior fascia urogenital diaphragm (transverse perineal ligament) with inferior fascia of pelvic diaphragm at the pubic bone
    • Posterior - open into the posterior recess of the ischiorectal fossa
    • Lateral - inferior - conjoint ramus, intermediate - oburtator internus muscle
    • Medial - fusion of the inferior fascia of the pelvic diaphragm with superior fascia urogenital diaphragm at urogenital hiatus
  • Boundaries of Posterior Recess
    • Superior - inferior fascia of the pelvic diaphragm
    • Inferior - medial: perianal skin, lateral: gluteus maximus
    • Anterior - superior to posterior free edge urogenital diaphragm: anterior superior recess of the ischiorectal fossa, inferior to posterior free edge of urogenital diaphragm: superficial perineal fascia (Dartos)
    • Posterior - gluteus maximus
    • Lateral - gluteus maximus
    • Medial - anal canal
  • Fascial specializations
    • Arcus tendineus - thickening of obturator internus fascia, faces pelvic cavity on superior aspect and ischiorectal fossa on inferior aspect
    • Pudendal canal - thickened covering of obturator internus fascia over falciform edge along medial ischial tuberosity forms osseofibrous pudendal canal from lesser sciatic foramen to the posterior free edge of the urogenital diaphragm at the conjoint ramus
  • Contents and relationships
    • Loose areolar fat - accomodate distention
    • Anal canal
    • Pudendal nerve and branches - inferior rectal, perineal, posterior scrotal, dorsal nerve
    • Internal pudendal artery and branches - inferior rectal, perineal, posterior scrotal, dorsal artery, deep artery, artery to the bulb
  • What fascial barriers prevent spread of infection into the superficial pouch
    • Infection does not spread from the ischiorectal fossa into the superficial pouch because Scarpa's fascia attaches to the posterior free edge of the UG diaphragm. This attachment provides part of the anterior border of the ischiorectal fossa at levels inferior to the posterior free edge of the urogenital diaphragm.
  • What fascial barriers prevent spread of infection into the deep pouch
    • Infection does not spread from the ischiorectal fossa into the deep pouch because the superior fascia of the urogenital diaphragm provides a fascial barrier between the anterior superior recess of the ischiorectal fossa and the deep pouch.
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Left Kidney

Discuss the structure, innervation, vasculature, lymphatics, and releationships of the left kidney. (12 pts)
  • Structure
    • medial and lateral margins
    • hilum and renal sinus
    • fibrous capsule
    • cortex and medulla
    • pyramids and renal papilla
    • major and minor calyx
    • renal pelvis
    • extends through hilum to become ureter
  • Position
    • paravertebral gutters
    • 11th thoracic to 3rd lumbar vertebra
  • Relations to peritoneum and fascia
    • perirenal fat - into renal sinus
    • renal fascia - condensation of ECT, open inferiorly (support and spread of infection)
    • pararenal fat - outside renal fascia, envelopes suprarenal gland and kidney
  • Relations to surrounding viscera (left kidney)
    • superior - suprarenal gland
    • inferior - false pelvis
    • posterior - diaphragm, lumbocosto trigone, 11-12 ribs, quadratus lumborum, psoas major
    • posteromedial - medial and lateral arcuate ligaments, subcostal nerve, iliocostal nerve
    • anteromedial - aorta
    • anterior - suprarenal g., omental bursa, stomach and leinorenal lig., spleen, tail of pancreas, left colic flexure, intestine, descending colon
  • Relations at the hilum
    • anterior to posterior - renal vein, renal artery, renal pelvis
  • Sensory and motor innervation
    • preganglionic sympathetics - imlcc of T10-12, synapse in aorticorenal g.
    • postganglionic sympathetics - renal plexus
    • sensory - T10 - L1, follow renal plexus, referred pain
  • vascular supply
    • left renal vein - crosses aorta in "nutcracker", anterior to renal artery,
    • left renal artery at level of L3,
  • lymphatic drainage
    • lumbar nodes
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Uterus, Uterine Tubes, and Ovary

Indicate your understanding of the uterus, uterine tubes, and ovary as to structure, orientation, relationships (anterior, posterior, superior, inferior, medial, lateral), support(s), and peritoneal associations, innervation (e.g., preganglionic, postganglionic, afferents, pawtways), vasculature, and lymphatics. (12 pts)
  • Uterus
    • Structure
      • Pear shaped hollow organ - 8cm long, 5cm wide
      • myometrium and endometrium
      • cervix, body, fundus
      • external os, cerivical canal, internal os, uterine cavity
    • Orientation
      • anteflexed and anteverted (lengthens posterior fornix vagina)
    • Support
      • intraperitoneal organ
      • Broad lig. - visceral lig (peritoneum)
        • lateral uterus to parietal peritoneum of lateral pelvic wall
      • fibrous ligs derived from endopelvic fascia
        • utereosacral, pubouteral, and lateral cervical (Cardinal) ligs.
      • round lig to lateral anterior pelvic brim - anterior lamina broad lig.
      • ovarian lig to posterior abdominal wall via suspensory lig. ovary
    • Relationships
      • anterior: bladder, vesicouterine pouch
      • posterior: rectum, rectouterine pouch
      • superior: false pelvis, abdominal cavity
      • inferior: vagina, posterior fornix, rectouterine pouch
      • lateral: broad lig, pelvic wall, ovary, uterine tube
    • vasculature and lymphatics,
      • uterine a. at the cervix and ovarian a. at the fundus
        • ovarian v. to ivc on right and left renal v. on left
        • uterine venous complex into internal iliac vv.
      • fundus drains lymph to upper lumbar nodes along ovarian vessels
      • superior body near round ligament drains lymph to superficial inguinal nodes
      • cervix drains lymph toward internal iliac nodes
    • innervation
      • sympathetic by way of inferior hypogastric plexus to uterovaginal plexus along uterine a.
        • preganglionic in IMLCC lower thoracic and upper lumbar
        • postganglionic in microscopic ganglia of aortic and hypogastric plexuses
      • parasympathetic: unknown if present
      • sensory pain follow sympathetic pathways (eg. hypogastric nerves)
  • Uterine Tube
    • Structure
      • shaped as a salpinx and about 10 cm long
      • connects uterine cavity to the peritoneal cavity
      • isthmus, ampulla, infundibulum, fimbriae
    • Orientation
      • courses laterally from fundus of uterus toward pelvic wall
      • intraperitoneal in superior free edge of broad lig.
      • cradles ovary as a posterior relation
    • Support
      • mesosalpinx - visceral lig (peritoneum) part of broad lig.
        • continuous with mesovarium
      • ovarian lig to posterior abdominal wall via suspensory lig. ovary
    • Relations
      • anterior: bladder, vesicouterine pouch
      • posterior: broad lig., rectum, rectouterine pouch, ovary
      • superior: false pelvis, abdominal cavity
      • inferior: broad lig., rectouterine pouch
      • lateral: broad lig, pelvic wall, ovary, ovarian fossa, uterine tube
      • medial: fundus and body of uterus
    • vasculature and lymphatics,
      • tubal a., uterine a. at the cervix and ovarian a. at the fundus
        • uterine venous complex to internal iliac vv
      • drains lymph to upper lumbar nodes along ovarian vessels
      • drains lymph to superficial inguinal nodes
      • drains lymph toward internal iliac nodes
    • innervation
      • sympathetic by way of inferior hypogastric plexus to uterovaginal plexus along uterine a.
        • preganglionic in IMLCC lower thoracic and upper lumbar
        • postganglionic in microscopic ganglia of aortic and hypogastric plexuses
      • sympathetic by way of ovarian plexus
      • parasympathetic: unknown if present
      • sensory pain follow sympathetic pathways
  • Ovary
    • structure and support
      • The ovary is roughly cylindrical about 3 cm long and 1 cm in diameter. The visceral peritoneum covering the ovary gives way to a specialized germinal epithelial cell layer. The egg is able to penetrate this layer and enter the peritoneal cavity.
      • The ovary is suspended from the posterior lamina of the broad ligament by the mesovarium -- a peritoneal ligament. Supporting the superior pole of the ovary to the pelvic brim is the suspensory ligament of the ovary. Supporting the inferior pole of the ovary to the lateral uterus is the ovarian ligament.
    • relationships
      • superior to the ovary is the pelvic brim and suspensory ligament
      • inferior to the ovary is the uterine wall and the ovarian ligament
      • anterior to the ovary is the broad ligament, uterine tube, and fimbria of uterine tube
      • posterior to the ovary is the rectum and pelvic floor
      • medial to the ovary is the pararectal fossa, rectouterine pouch, fundus of the uterus
      • lateral to the ovary is the ovarian fossa (internal iliac a. and ureter), psoas major muscle, and obturator n.
    • innervation (motor and sensory)
      • Parasympathetic preganglionic cell bodies are located in the central gray of the spinal cord (IMLCC) at levels S2-4. Preganglionic fibers enter the inferior hypogastric plexus by way of the pelvic splanchnic nerves. The inferior hypogastric plexus contributes a uterine plexus and then to the ovarian plexus. Postganglionic parasympathetic cell bodies are located in intrinsic ganglia of the ovary. The above pathway assumes that the uterovaginal plexus reaches the ovary. This is not known for certain. Parasympathetic pregangionic contributions from the vagus n. may also follow the ovarian plexus.
      • Sympathetic preganglionic cell bodies are located in the interomedial lateral cell column at cord levels T10 (and perhaps T11-12). Preganglionic fibers follow the lesser and least splanchnic nerves to aortic ganglia near (and including) the superior mesenteric ganglion and the aorticorenal ganglion. Postganglionic fibers from these ganglia enter the aortic plexus and extend along the ovarian artery as the ovarian plexus. Visceral afferent pathways follow the sympathetic pathways up to the T10 spinal level. Additional visceral pathways follow parasympathetic pathways back to the S3-4 spinal levels.
    • blood supply and lymphatics
      • The arterial supply is mostly from the ovarian arteries. These are paired arteries arising from the anterolateral surface of the aorta near the level of the third lumbar vertebra. The ovarian veins arise from the IVC on the right and the left renal vein on the left. Additional blood supply is by ascending branches of the uterine vessels (ovarian br.) that anastomose with the ovarian vascular supply. Lymph drainage is primarily along the embryological decent of the ovary. This includes upper lumbar nodes in the vicinity of the renal arteries. Much of the vascular supply reaches the ovary through the suspensory ligament.

  • Prolaps of Uterus
    • Weakening of the ligamentus support of the uterus leads to prolapse
      • most noteably, the lateral cervical ligs and important
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Topic revision: r1 - 08 Aug 2007, UnknownUser
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