Posterior Abdominal Muscles (Quiz 2/Exam 2) Flashcards
The thoracolumbar fascia is attached to the….
vertebral column
The psoas fascia covers the psoas major muscle and is thickened superiorly to form the _______________________. It fuses laterally with the quadratus lumborum and thoracolumbar fascia
medial arcuate ligament
How many layers does thoracolumbar fascia have?
3 layers- posterior, middle, and anterior
The thoracolumbar fascia has 3 layers. The posterior and middle layers enclose the ______________ muscles and the rectus sheath encloses the rectus abdominis. It is attached to the _______________ m.
erector spinae, latissimus dorsi
The anterior layer of the thoracolumbar fascia (quadratus lumborum fascia) is attached to the lumbar TPs and iliac crest and continues laterally with the aponeurotic origin of transversus abdominis muscle. It thickens superiorly to form the _______________________
lateral arcuate ligament
Which muscle can cause scoliosis if it is tight?
quadratus lumborum
What is the origin/superior attachment for the psoas major?
test q
-L1-L5 TPs
-lateral bodies of T12-L5 and their IVDs
What is the insertion/inferior attachment of the psoas major?
via strong tendon to lesser trochanter of the femur
What innervates the psoas major+ minor?
anterior rami of lumbar nerves L1-L3
What are the actions of psoas major?
acting inferiorly with iliacus= flexes thigh
acting superiorly= flexes vertebral column laterally and balances trunk
while sitting= acts with iliacus to flex trunk
What is the origin of the psoas minor?
T12-L1 vertebrae and their IVDs
40% of the population doesn’t have which posterior abdominal muscle?
psoas minor
What is the origin/superior attachment of the iliacus?
-superior 2/3 of iliac fossa
-ala of sacrum
-anterior sacro-iliac ligaments
What is the insertion/inferior attachment for the iliacus?
-lesser trochanter of the femur and shaft inferior to it
-psoas major tendon
What innervates the iliacus?
test q
femoral n.
What are the actions of the iliacus?
-flexes thigh and stabilizes hip joint
-acts with psoas major
The psoas and ilacus joint together form the iliopsoas muscle, which is the chief _________________
test q
flexor of the thigh
What is the origin/superior attachment for the quadratus lumborum?
medial half of inferior border of rib 12 and tips of lumbar TPs
What is the insertion/inferior attachment of the quadratus lumborum?
iliolumbar ligament and internal lip of iliac crest
What innervates the quadratus lumborum?
anterior branches of L1-L4 nerves
What are the actions of the quadratus lumborum?
-extends and laterally flexes vertebral column
-fixes 12th rib during inspiration
