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
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
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.
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)
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