The posterior abdominal wall Flashcards
What are the bones of the posterior abdominal wall?
Lumbar vertebrae
Ribs 11/12
Ilia
Sacrum
What are muscles of the posterior abdominal wall?
Diaphragm
Quadratus lumborum
Iliacus
Psoas
What is the diaphragm anchored by?
Crura (left and right crus)
Purpose of the central tendon of the diaphragm
to not crush the structures that pass through the hiatus
What are the levels of the structures that pass through the hiatus?
IVC - T8
Oesophagus - T10
Aorta - T12
Location of the quadratus lumborum
- Post to kidneys
- Superficially to the psoas major
Attachments of quadratus lumborum
- It originates from the iliac crest and iliolumbar ligament
- The fibres travel superomedially, inserting onto the transverse processes of L1-L4 and the inferior border of the 12th rib
What are the actions carried out by the quadratus lumborum?
- Extension and lateral flexion of the vertebral column
- It also fixes the 12th rib during inspiration, so that the contraction of diaphragm is not wasted
What is the innervation of the quadratus lumborum?
Anterior rami of T12-L4 nerves
Location of the psoas major
The psoas major is located near the midline of the posterior abdominal wall, immediately lateral to the lumbar vertebrae
What are the attachments of the psoas major?
Originates from the transverse processes and vertebral bodies of T12-L5.
It then moves inferiorly and laterally, running deep to the inguinal ligament, and attaching to the lesser trochanter of the femur
What are the actions of psoas major?
Flexion of the thigh at the hip lateral flexion of the vertebral column
What is the innervation of the psoas major?
Anterior rami of L1-L3 nerves
Location of psoas minor
Is only present in 60% of the population. It is located anterior to the psoas major
Attachments of psoas minor
Originates from the vertebral bodies of T12 and L1 and attaches to a ridge on the superior ramus of the pubic bone, known as the pectineal line
What are the actions of the psoas minor?
Flexion of the vertebral column
What is the innervation of the psoas minor?
Anterior rami of the L1 spinal nerve
Location of the iliacus
The iliacus muscle is a fan shaped muscle that is situated inferiorly on the posterior abdominal wall
It combines with the psoas major to form the iliopsoas - the major flexor of the thigh
What are the actions of the iliacus?
Flexion of the thigh at the hip joint
What is the innervation of the iliacus?
Femoral nerve (L2 - L4)
What is the vein/artery that supplies the diaphragm?
Sup and inf phrenic
What is the vein/artery that supplies the quadratus lumborum?
Lumbar