Flashcards in Abdomen/ Pelvis & Perioneum (Part II) Deck (26):
What are the four main muscles of the posterior abdominal wall?
Psoas major and minor
How does the psoas minor present in the cadaver?
As a long shiny tendon that runs to the pubis (it also runs over the psoas major)
True or false:
The anterior abdominal wall muscles also extend to the posterior abdominal wall. What are these muscles?
-these muscles are the transverse abdominalis, internal oblique and external oblique
What are the three arcuate ligaments of the posterior abdominal wall?
Three little arches that are formed by the diaphragm. They form a passageway for certain structures.
They are the median, medial, and lateral arcuate ligaments
What does the median arcuate ligament form and allow passage of?
The aortic hiatus...it allows for the passage of the aorta,, thoracic duct, greater thoracic splanchnic nerve and azygos vein
What does the medial arcuate ligament allow for the passage of? Where is this ligament found?
Sympathetic trunk, psoas muscle and iliophyogastric nerve; sits on top of the psoas major
What does the lateral arcuate ligament allow for the passage of? Where is this ligament found?
Quadratus lumborum muscle and subcostal nerve; sits on top of the quadratus lumborum muscle.
Name the three arcuate ligaments in order from medial to lateral and what forms them.
Median= tendinous arch of the R and L crus of diaphragm
Medial= fascia of psoas muscle fro L1 body to TVP
Lateral= fascia of QL from TVP of L1 to 12th rib
What group of nerves is formed within the psoas major muscle?
What forms the lumbar plexus?
Ventral primary rami of L1-L4
What forms the lumbosacral trunk? What does it contribute to?
The union of part of the ventral primary rami of L4 and part of the ventral primary rami of L5...this contributes to the sacral plexus
What are the cord levels for the 8 nerves of the lumbar plexus and the lumbosacral trunk?
Lateral Femoral Cutatneous=L2-L3
(Accessory Obturator)= L2-L4
Lumbosacral trunk= L4-L5
Where does the subcostal nerve exit?
Lateral arcuate ligament
Where does the iliohypogastric (L1) nerve run? What does it pierce?
Pierces the transverse abdominalis and then runs between the internal and external obliques
Where does the ilioinguinal (L1) nerve run? What does it go through?
It goes the inguinal canal (enters deep inguinal ring and exits superficial ring) and initially runs between the internal oblique and transverse abdominalis but then it runs between the internal and external obliques
Where does the genitofemoral (L1-L2) nerve run?
In front of the psoas major muscle...it then splits and the femoral portion runs to the anterior thigh and the genital portion runs to the labia or scrotal area
Where does the lateral femoral cutaneous nerve (L2-L3) run?
Exits lateral to the psoas muscle and then runs over the iliacus muscle
Where does the obturator nerve (L2-L4) run?
It passes into the medial thigh to innervate the adductors....it exits through the obturator foramen
Where would the obturator accessory nerve (L2-L4) run is present?
Just lateral to the obturator nerve
Where does the femoral nerve run?
Lateral and posterior to the psoas major muscle
What are the paired arteries of the posterior abdominal wall coming off the aorta? How many are there?
There are 6
-inferior phrenic (course up to feed the diaphragm)
-superior adrenal (suprarenal) that come off the inferior phrenic
-renal arteries (found at the hilum of the kidney)
-gonadal (ovarian or testicular)
-4-5 pairs of lumbar (segmental) arteries
-common iliac artery
What do the lumbar (segemental) arteries do?
Help feed the posterior abdominal wall and may also help feed the IVDs and spinal cord
What do the common iliac arteries split into? What do those then do from there?
Common iliac splits into the external and internal iliac arteries. The external becomes the femoral artery and the internal dives deep to give off branches to the pelvic viscera
What is special about the left renal vein?
It has to run across the aorta in order to reach the IVC
What is the main collecting duct of the abdominal lymphatic system?