THE ABDOMINAL WALL Flashcards
What is the origin of the External obliques?
Ribs 5-12
The External obliques are one of the muscles that make up the abdominal wall.
Where do the External obliques insert?
Iliac crest, inguinal ligament, linea alba, pubic tubercle
These insertions help facilitate their actions.
What is the action of the External obliques when contracting bilaterally?
Anterior flexion of the trunk and compression of the abdomen
This means both sides contract to bend the trunk forward and compress the abdominal cavity.
What is the action of the External obliques when contracting unilaterally?
Lateral flexion of the trunk and rotation to the opposite side
This indicates that when one side of the muscle contracts, it bends and rotates the trunk.
What is the origin of the Internal obliques?
Iliac crest, inguinal ligament, thoracolumbar fascia
The Internal obliques are located beneath the External obliques.
Where do the Internal obliques insert?
Ribs 10-12, pectineal line, linea alba/ abdominal aponeurosis
These insertions assist in various trunk movements.
What is the action of the Internal obliques when contracting bilaterally?
Anterior flexion of the trunk and compression of the abdomen
Similar to the External obliques, they assist in bending forward and compressing the abdomen.
What is the action of the Internal obliques when contracting unilaterally?
Lateral flexion of the trunk and rotation to the same side
This means that one side of the muscle helps bend and rotate the trunk towards that side.
What is the origin of the Transverse abdominis?
Iliac crest, thoracolumbar fascia, costal cartilages of ribs 7-12
This muscle plays a key role in abdominal compression.
Where does the Transverse abdominis insert?
Abdominal aponeurosis
This insertion helps facilitate its primary function.
What is the primary action of the Transverse abdominis?
Compression
It is primarily responsible for compressing the abdominal contents.
What is the origin of the Rectus abdominis?
Pubic crest and symphysis
This muscle is commonly referred to as the ‘abs’.
Where does the Rectus abdominis insert?
Costal cartilages 5-7, xiphoid process
These points of insertion allow for trunk flexion.
What is the action of the Rectus abdominis?
Flexion of the trunk
This muscle is primarily responsible for bending the torso forward.
What is the origin of the Quadratus lumborum?
Iliac crest
This muscle is located in the lower back.
Where does the Quadratus lumborum insert?
Transverse process L1-L5; rib 12
This allows it to stabilize the lower back.
What is the primary action of the Quadratus lumborum?
Extension of the trunk and lateral flexion
It primarily contributes to stability, especially in an upright position.
