Axial Muscles- Muscles of the Abdominal Wall Flashcards
1
Q
What are abdominal wall muscles?
A
- The anterolateral wall of the abdomen is reinforced by 4 pairs of muscles that collectively compress and hold the abdominal organs in place
- The external oblique, internal oblique, transversus abdominis and rectus abdominis
- This muscle action increases intra abdominal pressure and so these muscles are used to forced exhalation
- These muscles (except for transversus abdominis) also work together to flex the vertebral column
2
Q
What is the external oblique?
A
- It’s a superficial muscle
- It’s muscle fibers are directed inferomedially
- It’s muscular along the lateral abdominal wall and forms an aponeurosis as it projects anteriorly
3
Q
What is the inguinal ligament?
A
- Inferiorly, the aponeurosis of the external oblique forms a strong, cord-like inguinal ligament
- Extends from the anterior superior iliac spine to the pubic tubercle
4
Q
What is the internal oblique?
A
- Immediately deep to the external oblique
- It’s muscle fibers project superomedially which is at right angles to the external oblique
- Muscle forms an aponeurosis as it projects anteriorly
- Unilaterally the external and the opposite sides of the internal oblique work together to rotate the vertebral column
5
Q
What is the transverse abdominis?
A
- The deepest muscle
- Fibers project transversely across the abdomen
6
Q
What is the rectus abdominis?
A
- A long, strap-like muscle that extends vertically the entire length of the anteromedial abdominal wall between the sternum and the pubic symphysis
- Partitioned into 4 segments by 3 fibrous tendinous intersections which form the traditional 6 pack (toned muscular abdominal wall)
7
Q
What is the rectus sheath?
A
- Fibrous sleeve that incloses the rectus abdominis
- Formed from the aponeuroses of the external oblique, internal oblique and transversus abdominis muscles
- Left and right rectus sheaths are connected by a vertical fibrous strip called the linea alba
