the posterior abdominal wall - posterior abdominal muscles Flashcards
what is the posterior abdominal wall formed from?
lumbar vertebrae, pelvic girdle, posterior abdominal muscles, associated fascia
what is located on the inner surface of the posterior abdominal wall?
major vessels, nerves, organs
what are the posterior abdominal muscles?
quadratus lumborum psoas major psoas minor iliacus (diaphragm)
where is the quadratus lumborum located?
laterally in the posterior abdominal wall
what shape is the quadratus lumborum?
thick muscular sheet which is quadrilateral in shape
where is quadratus lumborum positioned?
superficially to psoas major
what is the origin of the quadratus lumborum?
iliac crest and liolumbar ligament
where do the quadratus lumbroum fibres travel?
superomedially
where does the quadratus lumborum insert?
onto transverse processes of L1-L4 and inferior border of 12th rib
What is the action of quadratus lumborum?
extension and lateral flexion of the vertebral column
also fixes 12th rib during inspiration, so that contraction of diaphragm isn’t wasted
what is the innervation of quadratus lumborum?
anterior rami of T12-L4 nerves
Where is psoas major located?
near the midline of the posterior abdominal wall, immediately lateral to the lumbar vertebrae
where is the origin of psoas major?
transverse processes and vertebral bodies of T12-L5
where does the psoas major move from transverse processes and vertebral bodies of T12-L5?
moves inferiorly and laterally, running deep to the inguinal ligament
where does psoas major attach?
lesser trochanter of the femur
what is the action of psoas major?
flexion of the thigh at the hip and lateral flexion of the vertebral column
what is the innervation of psoas major?
anterior rami of L1-L3 nerves
where is the psoas minor located?
anterior to psoas major
where does the psoas minor originate from?
vertebral bodies of T12-L1
where does psoas minor attach to? what is it known as?
ridge on the superior ramus of the pubic bone, known as pectineal line
what is the action of psoas minor?
flexion of the vertebral column
which nerve innervates psoas minor?
anterior rami of L1 spinal nerve
what shape and where is the ilicaus muscle found?
fan-shaped muscle situated inferiorly on the posterior abdominal wall
what does the iliacus combine with? what does it form?
iliacus combines with psoas major to form iliopsoas
what is the function of iliopsoas?
major flexor of the thigh
where does iliacus originate from?
surface of iliac fossa and anterior inferior iliac spine (AIIS)
what happens to the fibres of iliacus?
combine with tendon of psoas major
where does iliacus insert into?
lesser trochanter of femur
what is the action of iliacus?
flexion of the thigh at the hip joint
what innervates the iliacus? nerve roots?
femoral nerve (L2-L4)
which part of the diaphragm is considered to be part of the posteriro abdominal wall?
posterior aspect of diaphragm
what is the psoas sign?
a medical sign that indicates irritation to the iliopsoas group of muscles
what is the psoas sign elicited by?
flexion of the thigh at the hip
when is the psoas sign test positive?
when the patient reports lower abdominal pain
what is an indication of appendicitis?
right sided psoas sign
what happens as the iliopsoas contracts? (in appendicitis)
it comes into contact with the inflamed appendix, producing pain
