The Posterior Abdominal Wall Flashcards
Some specific bones create the framework for the posterior abdominal wall (PAW). What are 4 bones (groups) labelled 1-4 in the figure below that create the framework for the PAW?
1 - vertebral column
2 - ilia (pleural of iliac)
3 - sacrum
4 - ribs 11-12
Where does the posterior abdominal wall (PAW) begin in relation to the ribs?
- ribs 11 and 12
Which vertebrae contribute the majority of the posterior abdominal wall?
- lumbar vertebrae
There are 4 main muscles that contribute towards the posterior abdominal wall, labelled 1-4 in the image below. What are there names?
- diaphragm is also included
1 - quadratus Lumborum
2 - iliacus
3 - psoas minor
4 - psoas major
The diaphragm is one of the 4 major muscles that contributes towards the the posterior abdominal wall. Where does it originate from?
- cura (left and right tendons) from lumbar vertebrae & discs
- costal cartilages of ribs 7-10
- xiphoid process
What are the 2 major componenets of the diaphragm?
- muscle and tendon
- muscle become aponeurotic and forms central tendon
What are the 3 passageways of the diaphragm? This mnemonic may help: I Eight 10 Eggs At 12 oclock.
- I Eight = Inferior Vena Cava at T8
- 10 Eggs = Oesophagus at T10
- At 12pm = Aorta at T12
The posterior aspect of the diaphragm contributes the majority of the of the diaphragm towards the posterior abdomainl wall. The are 2 parts of the diaphragm that anchor it to the vertebrae, what are these called?
- crus (means anchor or root)
- thick attachment
- right is thicker and more extensive
The posterior aspect of the diaphragm contributes the majority of the of the diaphragm towards the posterior abdomainl wall through the left and right crus (means anchor or root). The right is thicker and more extensive, why is this important?
- forms a loop around the oesophagus
- forms a physiological sphinter for the oesophagus
- reduces reflux on stomach into oesophagus
The quadratus lumborum is one of the 4 major muscles that contributes towards the the posterior abdominal wall. Where does it originate and insert?
- origin = iliac crest
- insertion = rib 12 and T12 down to L5 vertebrae
- merges laterally to transversus abdominis muscle
The quadratus lumborum is one of the 4 major muscles that contributes towards the the posterior abdominal wall. What is the function of the quadratus lumborum?
- abdominal stability/lateral flexion
- ensures rib cage doesnt shift too much during respiration
The psoas major is one of the 4 major muscles that contributes towards the the posterior abdominal wall. Where does the psoas major originate and insert?
- origin = T12 down to L5 on transverse processes & vertebral bodies
- insertion = lesser trochanter of femur
The iliacus is one of the 4 major muscles that contributes towards the the posterior abdominal wall. Where does the iliacus originate and insert?
- insertion = trochanter minor femoris
- origin = iliac surface/fossa of hip (pelvic) bone on each side
The iliacus and the psoas major are 2 of the major muscles that contributes towards the the posterior abdominal wall. These muscles merge in the pelvis and connect to which bone?
- femeur
In addition to the 4 main muscles that make up the posterior abdominal wall PAW), what other large muscle group that allows flexion and extension of the spine completes the PAW?
- erector spinae
The erector spinae, quadratus Lumborum and psoas major all form part of the posterior abdominal wall (PAW). But are they in direct contact or are they seperated by something?
- seperated by a thick deep fascia
- fascia is called the thoracolumbar fascia
The erector spinae, quadratus lumborum and psoas major all form part of the posterior abdominal wall (PAW). The thoracolumbar fascia is a thick deep fascia that seperates the erector spinae and the quadratus lumborum. How many layers of the thoracolumbar fascia are there?
- 3
- anterior
- middle
- posterior
The erector spinae, quadratus lumborum and psoas major all form part of the posterior abdominal wall (PAW). The thoracolumbar fascia is a thick deep fascia that seperates the erector spinae and the quadratus lumborum. Which layers of the thoracolumbar fascia surround the quadratus lumborum?
- anterior and medial
Ther fasica, such as the thoracolumbar fascia that contribute to the posterior abdominal wall have 2 main functions, what are they?
1 - maintain muscle shape
2 - protect muscles from infection
Is the psoas major surrounded by the thoracolumbar fascia?
- no
- has its own fascia
In patients who have tuberculosis (TB), there is a risk that the infection can spread to the vertebral bones. This can infect the muscles attaching to the vertebrae. How does the fascia of the psoas major protect other muscles and tissues within the abdomen from the TB infection?
- fascia ensure within the fascia only affecting the psoas major
- eventially collects in groin as an abscess
There are 3 sites of constrcition in the urinary system. The first site is located where the renal pelvis meets the uereter. Why is there a constriction at this site?
- the renal pelvis narrows to facilitate flow into the ureter
There are 3 sites of constrcition in the urinary system. The second site is located where the ureter crosses over the iliac, called the iliac vessels/pelvic brim. Why is there a constriction at this site?
- ureter is crossing a ridge in the bone which compresses the ureter
There are 3 sites of constrcition in the urinary system. The third site is located where the ureter meets the bladder/ischial spine. Why is there a constriction at this site?
- the ureter narrows to enter the bladder
Why are the 3 contraction areas of importance in the urinary tract?
- these sits are where renal stones are most likley to occur
What are uteric calculi more commonly known as?
- kidney stones
On radiology where would the 3 site on constriction of the urinary system Pelvi-ureteric junction/L2-L3, Crossing iliac vessels/pelvic brim and Entering bladder/ischial spine. Where would these come up on radiography?
- 1st site = L2-L3 (transverse process)
- 2nd site = sacroiliac joint
- 3rd site = ischial spine