Anatomy of the Lateral Pelvic Wall and Mass Flashcards
What is the consequence of having a foreign object (mass) in pelvic cavity?
Impingement on other structures as pelvic cavity is small
How to identify an obturator vessel?
Any time a vein, artery or nerve heads towards obturator canal it is an obturator vessel
What are the muscles of the lateral pelvic walls?
Levator ani
Coccygeus
Obturator internus
Piriformis
Which muscle is deep to levator ani?
Obturator internus
List the muscles invovled in lateral rotation of the hip
Obturator internus
Piriformis
What is the arterial supply of lateral pelvic wall?
Majority of arteries of pelvis and perineum arise from internal iliac artery
Extensive anastamoses
What are the exceptions to arterial supply from internal iliac artery?
- Gonadal artery: L2 abdominal aorta
- Superior rectal artery: Continuation of inferior mesenteric
What are the visceral and parietal divisions of the internal iliac artery (male)?
Visceral: anterior division
Parietal: posterior division
Which artery heads towards obturator canal?
Obturator artery
Which artery connects embryo’s internal iliac to the placenta?
Median umbilical ligament - remnant of the umbilical artery
Which arteries supply bladder (male)?
Superior and inferior vesicle
No inferior vesicle artery in female, however this is being disproved by research papers
Which is the main pelvic artery that supplies most of the structures (male)?
internal pudendal
exits at greater sciatic foramen and re enters at lesser sciatic foramen
List the arterial supply of the perineum
internal pudendal artery perineal artery Posterior scrotal Anterior scrotal Deep artery of penis Dorsal artery of penis
Artery supplying corpus cavernosum?
Deep artery of the penis
Where does uterine artery come from?
Anterior division of common iliac
Which surgical procedure requires ligation of uterine artery?
Hysterectomy
Which female pelvic artery is homologous to vas deferens artery?
Uterine artery
Name the branch of the uterine artery that supplies vagina?
Vaginal artery
Which female pelvic artery is homologous to inferior vesical artery in males?
Vaginal artery (variable, 60-70% of the time)
List the two sites of anastomoses of pelvic arteries in females
- Between uterine artery and ovarian artery
2. Between uterine artery and vaginal artery
What is the clinical importance of uterine artery ligation?
Ureter passes right underneath the uterine artery. If you ligate the uterine artery, be aware of the proximity of the ureter.
Which artery gives of branches that anastomose further with vaginal artery?
Internal pudendal artery
List the arteries of the female perineum
Internal pudendal artery Inferior rectal artery Labial arteries Perineal arteries Dorsal artery of clitoris
What is the most important feature of venous drainage of pelvis?
Formation of venous plexuses
Describe venous drainage of pelvis
Drain mainly to internal iliac vein
- some will drain via superior rectal into hepatic portal system
- some will drain via lateral sacral veins into internal vertebral venous plexus
Clinical significance of venous plexus of pelvis
Infection and cancer can spread to vertebral column via lateral sacral venous plexuses (on either side of sacrum)
This is also true of pre-sacral plexus.
What are the nerves of the lateral wall?
Obturator Nerve* - L2,3 4 Sciatic nerve Pudendal Nerve to LA Sacral plexus Pelvic splanchnic nerves - parasympathetic, supply pelvic organs
What is the origin of most nerves of lateral wall
Sacral plexus
What are the main groups of the lymphatics of the pelvis?
- Para rectal - either side of rectum
- Sacral
- Internal iliac
- External iliac
- Superficial inguina
- Deep inguinal
- Common iliac
- Inferior mesenteric
- Lumbar
General rules of pelvic lymphatics
Superior Pelvic Viscera:
- external iliac nodes
- common iliac, aortic, thoracic duct, venous system
Inferior Pelvic Viscera:
- deep perineum
- internal iliac nodes
- common iliac, aortic, thoracic duct, venous system
Superficial perineum:
- superficial inguinal nodes
Are the lymph node patterns and its drainage fixed?
Nope, highly variable This is only a general idea High cross-over Cancer can spread into any direction Pattern not sufficiently predictable to anticipate spread.
Describe trans-peritoneal spread
Usually the peritoneum draping over pelvic organs acts a as a barrier. However, it is only a single celled membrane, hence aggressive cancers can penetrate and the peritoneum is no longer a barrier and aids spread instead.
Also, little cells can slough off into the peritoneal cavity (between visceral and parietal peritoneum) into fluid which then allows the cancer cells to circulate the peritoneal cavity