Flashcards in Posterior Abdominal Wall Deck (277)
What are the muscles of the posterior abdominal wall
Where is the iliacus located?
Large triangular muscle located lateral to the inferior part of psoas major
What is the origin of the iliacus?
Ala of sacrum, iliac fossa and anterior sacroiliac l.
What is the insertion of the iliacus?
Lesser trochanter of femur with psoas major m.
What is the innervation of the iliacus?
Femoral n. (L2-4)
What is the action of the iliacus?
Flexes thigh and stabilizes hip joint
What and where is the quadratus lumborum located?
Quadrilateral shaped muscle forming a sheet on posterior abdominal wall
What crosses superiorly over the quadratus lumborum?
Lateral arcuate ligament
What nerves cross the quadratus lumborum?
Subcostal n. and branches of lumbar plexus cross this m.
What is the origin of the quadratus lumborum?
12th rib and lumbar TPs
What is the insertion of the quadratus lumborum?
Iliolumbar l. and iliac crest
What is the innervation of the quadratus lumborum?
VPR of T12-L4
What is the action of the quadratus lumborum?
Depresses/stabilizes 12th rib for respiratory muscles (thoracic diaphragm
contracts against it during inspiration); laterally flexes vertebral column
What lines the posterior abdominal wall?
Lined internally by parietal peritoneum
Where is endoabdominal fascia found?
Between parietal peritoneum and musculature
What is the endoabdominal fascia continuous with?
Continuous anteriorly with transversalis fascia on anterolateral abdominal wall
What and where is the thoracolumbar fascia found?
Thin and transparent in thoracic region
Thick and strong in lumbar region
- Attached to vertebrae and spans between 12th rib and iliac crest
How is the thoracolumbar fascia found in regards to the deep back mm.?
Anterior, middle and posterior layers split to enclose deep back mm
Between which layers of the thoracolumbar fascia are the quadratus lumborum located and what muscles attach laterally?
Quadratus lumborum m. located between anterior and middle layers
- Internal abdominal oblique and transversus abdominis mm. attach laterally
Between which layers of the thoracolumbar fascia are the erector spinae mm. located and what muscles attach posteriorly?
located between middle and posterior layers
- Comparable to rectus sheath, but stronger due to vertebrae
- Latissimus dorsi m. attaches to lateral aspect of posterior layer
What are fascial abscesses?
Vertebral disease or infection may spread though psoas sheath
- Fascial compartment surrounding psoas major m.
What do fascial abcesses do to the fascia?
Psoas abscess causes this fascia to thicken and become very taut
Where does pus from fascial abcesses travel and via what?
Pus will spread through this compartment to the superior thigh
-Via lacuna musculorum
What will pus from fascial abcesses do to the muscle?
Pus accumulation will compress this muscle and cause pain
What are the somatic nerves of the posterior abdominal wall?
lumbar plexus of nerves
- lateral femoral cutaneous
- lumbosacral trunk
What is the nerve root of subcostal n?
VPR of T12
where is the subcostal nerve found?
- Located just inferior to 12th rib
- Laterally located between transversus abdominis and internal oblique mm.
- Passes posterior to lateral arcuate l. and crosses quadratus lumborum m.
What does the subcostal nerve innervate?
Innervates anterolateral abdominal wall mm. and T12 dermatome
What do the dorsal rami of lumbar spinal nerves supply?
Dorsal rami supply mm. and skin of back