L5 The Abdomen

Question 1

Name the different layers of the Rectus Sheath in order as well as their function/nature

Answer 1

1. Skin
2. Camper’s fascia
   
   • Sub-cutaneous fatty layer
   • Camping outside – Fat to keep warm
3. Scarpa’s fascia
   
   • Deep membranous tissue
   • Holds the muscles
4. Anterolateral muscles of the abdominal wall
   
   • External/Internal obliques
   • Transversus abdominis
   • Rectus abdominis
5. Transversalis facia
6. Peritoneum

Question 2

What are the three layers of lateral muscles of the anterior abdominal wall?

Answer 2

• Aponeurosis
  
  • Large, broad tendon
  • 3 attaches together along the linea alba (midline)
  • Linea semi-lunaris more distally
• External oblique muscle ( \ )
  
  • Contralateral rotation
  • Insertion (pelvis) is stationary
    
    • Contraction is simply bringing muscles together
• Internal oblique muscle ( / )
  
  • Ipsilateral rotation
  • Works in symmetry with opposite external oblique muscle
• Bilateral functions: Common functions (Protection, accessory for respiration)
• Transversus abdominis (–)
  
  • Horizontal fiber

Question 3

Name of the muscle/function?

Answer 3

• Rectus abdominis
  
  • Flexion
  • Separated by tendinous intersections
  • Lateral borders line up with linea semilunaris

Question 4

Describe the aponeurosis arrangement (arcuate line)

Answer 4

• Above the arcuate line
  
  • Internal oblique aponeurosis splits into two (around the rectus abdominis)
• Below the arcuate line (belly button)
  
  • All aponeurosis go anteriorly of the rectus abdominis
    
    • Creates opening for the inferior epigastric a. / v.
  • Superior epigastric a. (wraps the gastric region)
    
    • Anastomosis
  • Inferior epigastric a.

Question 5

What are the two branches of arteries supplying the abdominal region?

Answer 5

• Internal thoracic artery
  
  • Superior epigastric artery
  • Anastomosis
  • Inferior epigastric artery
• External iliac artery

Question 6

Which spinal nerves innervate the abdominal region?

Answer 6

• Thoracoabdominal nerves (T7-T11)
• Lateral/anterior cutaneous nerves of T12

Question 7

What are the posterior muscles of the abdominal region?

Answer 7

• Iliopsoas
  
  • Psoas minor
    
    • O- T12 and L1 I- Pubic bone
  • Psoas major
    
    • O- T12 to L5 I- Pubic bone
  • Iliacus
    
    • O- Lumbar I- Lower limb
• Quadratus lumborum
  
  • O- TP of lumbar vertebrae and rib 12 I-Iliac crest

Question 8

Insertion, openings and components of the diaphragm?

Answer 8

• Three openings
• Caval hiatus – T8
  
  • Inferior vena cava
  • Caval = vena cava
• Esophageal hiatus – T10
  
  • Thorax into abdomen
  • Food
• Aortic hiatus – T12
  
  • Aorta
    
    • Reverse alphabetical (I E A)
    • Numerical order (8 10 12)
• Insertion on:
  
  • Lateral, medial and median ligaments (actually tendons)
  • Median ligament
    
    • Right + left crus
    • Aortic hiatus
    • Right crus laps around itself to make esophageal hiatus