Abdomen, Pelvis and perineum 1 Flashcards
What is the anterolateral abdominal wall?
Muscular wall of the abdomen
What is the role of the anterolateral abdominal wall?
1) Protect the viscera within the abdomen
2) Serve as accessory muscles for respiration
3) Compress the abdominal contents to increase intra-abdominal pressure during coughing, sneezing, defecation and parturition
4) Provide movement of the trunk
What is the origin of the rectus abdominis?
5th, 6th and 7th costal cartilages
What is the insertion of the rectus abdominis?
Pubic crest
What are the bands of tendon that divide the rectus abdominis called?
Tendinous intersections
How many tendinous intersections are there in the rectus abdominis?
3-4
What is the action of the rectus muscles?
- Produce flexion of the lumbar spine
- Keep the lumbar spine straight when gravity would extend it
What group of muscles do the rectus muscles work in opposition with?
The erector spinae muscles
What structure encloses the rectus abdominis
A tendinous envelope that is formed buy the aponeuroses of the 3 flat muscles. The aponeuroses are called:
- The posterior rectus sheath
- The anterior rectus sheath
Where does the anterior rectus sheath extend to and from?
From the costal margin to the pubis
What part of the rectus abdominis does the anterior rectus sheath bind to?
The tendinous intersections
Where do the posterior and anterior rectus sheaths insert into?
Linea Alba
Dense midline band of tendinous tissue
Where does the linea alba extend to and from
From the xiphoid process to the pubis
Name number 1 on this diagram
Rectus abdominis muscle
Name number 4 on this diagram
Linea Alba
What is the origin of the transversus abdominis?
At the top: Inner aspect of the costal margin, from the 6th-12th rib
Between the 12th rib and the ileum: Edge of the thoracolumbar fascia
Below: Inner aspect of the iliac crest
Where do the muscle fibres of the transversus abdominis end?
The transversus aponeurosis
What is the origin of the internal oblique muscle?
The thoracolumbar fascia and the iliac crest
How do the lowest fibres of the internal oblique muscles arise?
From a thickening of the iliopsoas fascia
What is the insertion of the internal oblique muscle?
Highest fibres: Ribs 10,11 and 12
Other fibres: Internal oblique aponeurosis
What is the origin of the external oblique muscle?
Posterior: 12TH-10TH rib
Anterior: 9th to the 5th rib
- The zig zag line of the origin complements that of the serratus anterior.
What is the insertion of the anterior part of the external oblique muscle?
The external oblique aponeurosis
What structures join together to form the anterior rectus sheath?
The external oblique, internal oblique and transversus aponeuroses
What is the inguinal ligament?
The free lower border of the external oblique aponeurosis
What is the insertion of the posterior part of the external oblique muscle?
Inserts in the anterior part of the iliac crest
What are the 3 flat muscles?
- Transversus abdominis
- External oblique
- Internal oblique
What is the origin of the external abdominal oblique muscle?
External inferior borders of ribs 5-12
What is the insertion of the external abdominal oblique muscle?
Anterior superior iliac spine
Anterior half of iliac crest