Anterior Abdominal Wall & Inguinal Region Flashcards
What is the definition of the anterior abdominal wall?
A musculomembranous layer that allows movement, protection and stability of the trunk
What are the layers that make up the anterolateral abdominal wall?
From superficial to deep:
- skin
- subcutaneous tissue (fatty)
- muscle layers
- peritoneum
Why does there tend to be more blood lost during surgery in obese patients?
They have more subcutaneous fat
fat requires a blood supply, so there are more blood vessels present supplying the fat
What are the two layers of subcutaneous tissue in the anterolateral abdominal wall?
- Camper fascia
This is a superficial fatty layer of subcutaneous tissue
- Scarpa fascia
This is a deep membranous layer of subcutaneous tissue
What are the 3 muscle layers that form the anterolateral abdominal wall?
- external oblique
- internal oblique
- transversus abdominis
What are the 3 fascia that separate the muscles of the anterolateral abdominal wall?
- superficial fascia
- intermediate fascia
- deep fascia
- transversalis fascia
(after transversus abdominis)
What immediately follows the transversalis fascia?
Extraperitoneal fat followed by parietal peritoneum
By which muscles are the 3 paired muscles of the anterolateral abdominal wall supported by?
- rectus abdominis
2. quadratus lumborum
What is the linea alba?
The region where the aponeuroses from either side of the body interdigitate in the midline
In which direction do the fibres of the external oblique muscles run?
Forwards and downwards
hands in pockets
How is the right external oblique attached to the left external oblique?
Why does it attach in this way?
They are attached through the external oblique aponeurosis
There is no bone in the midline for a tendon to attach on to
How is the external oblique aponeurosis formed?
How would it be described?
A flattened tendinous sheet formed by the left and right external oblique coming towards the midline and interdigitating
What is the fibre orientation of the internal oblique muscles?
Opposite to the external oblique
Upwards and backwards
How is the internal oblique aponeurosis formed?
From the right and left internal oblique muscles coming towards the midline and interdigitating
In which direction do the fibres of the transversus abdominis muscle run?
Do they have an aponeurosis?
In the transverse plane
They have an aponeurosis which forms in the midline
How are the muscles of the anterolateral abdominal wall involved in movement?
They are involved in movement of the trunk through lateral rotation and flexion
How do the muscles of the anterolateral body wall help to keep the body upright?
When they contract, they help to keep the vertebral wall upright as they work alongside muscles in the posterior abdominal wall
What are the other 2 functions of the muscles of the anterolateral abdominal wall?
- they provide some kind of protection to the abdominal viscera
- they act to increase intraabdominal pressure which helps to expel things
(e. g. vomiting and defecation)
Where does the rectus abdominis muscle run from?
It runs from the costal margin down towards the pubic tubercle
There is one on either side
What is present between the muscle bellies of the rectus abdominis muscles?
tendinous intersections
What is the role of the rectus abdominis muscle?
Mainly movement and flexion of the trunk
It is also involved in forced expiration and increasing intra-abdominal pressure
What is the role of the quadratus lumborum muscle?
It works with the anterior muscles to keep the body upright and maintain the posture
Where is the internal thoracic artery found?
It lies on either side of the sternum
What are the 2 branches of the internal thoracic artery and what do they supply?
- musculophrenic artery goes towards the muscles and part of the diaphragm
- superior epigastric artery supplies the superior region of the abdominal wall
What happens to the superior epigastric artery on the anterior abdominal wall?
It forms an anastomosis with the inferior epigastric artery
What is an anastomosis of 2 arteries?
2 arteries are coming from different regions to supply the same area
Where does the inferior epigastric artery arise from?
femoral artery
What other vessels does the femoral artery give rise to?
superficial epigastric artery
deep circumflex arteries