Anterolateral abdomen Flashcards
External oblique - attachment, innervation, action
Origin: External surfaces of 5th-12th rib.
Insertion: Linea alba, pubic tubercle, anterior half of iliac crest.
Innervation: Thoraco-abdominal nerves and subcostal nerve.
Action: Compresses and supports abdominal viscera, flexes and rotates trunk.
Internal oblique - attachment, innervation, action
Origin: Thoracolumbar fascia, anterior 2/3 of iliac crest, connective tissue deep to lateral third of inguinal ligament.
Insertion: Inferior borders of 10th-12th ribs, linea alba, pecten pubis via conjoint tendon.
Innervation: Thoraco-abdominal nerves (anterior rami of T6-T12), first lumbar nerves.
Action: Compresses and supports abdominal viscera, flexes and rotates trunk.
Transversus abdominis - attachment, innervation, action
Origin: Internal surfaces of 7th-12th costal cartilages, thoracolumbar fascia, iliac crest, connective tissue deep to lateral third of inguinal ligament.
Insertion: Linea alba with aponeurosis of internal oblique, pubic crest, pecten pubis via conjoint tendon.
Innervation: Thoraco-abdominal nerves (anterior rami of T6-T12 and first lumbar nerves.
Action: Compresses and supports abdominal viscera.
Rectus abdominis - attachment, innervation, action
Origin: Pubic symphysis and pubic crest.
Insertion: Xiphoid process and 5th-7th costal cartilages.
Innervation: Thoraco-abdominal nerves (anterior rami of T6-T12).
Action: Flexes trunk, compresses abdominal viscera, stabilizes and controls tilt of pelvis (antilordosis).
Muscles of anterolateral abdominal wall.
External oblique.
Internal oblique.
Transversus abdominis.
Rectus abdominis.
Midinguinal points
Midpoints of the lines joining the anterior superior iliac spina and pubic tubercles on each side.
- Subcostal plane
2. Transtubercular plane
(Transverse planes)
- Passes through inferior border of 10th costal cartilage on each side.
- Passes through the iliac tubercles and body of L5.
Transpyloric plane
Extrapolated midway between the superior borders of the manubrium and pubic symphysis.
Interspinous plane
Passes through ASIS on each side.
Transumbilical plane
Passing through the umbilicus (The horizontal line that divides the upper and lower quadrants.
Bounderies of the anterolateral abdominal wall
Superiorly: Cartilages of 7th-10th ribs and xiphoid process.
Inferiorly: Inguinal ligament and superior margins of anterolateral aspects of the pelvic girdle (Iliac crests, pubic crests, pubic symphysis).
Linea alba
A midline raphe formed by the recus sheaths and aponeuroses of anterolateral abdominal muscles. Also between superficial and intermediate and intermediate and deep layers.
Extends from xiphoid process to pubic symphysis.
Contents of rectus sheath
Rectus abdominis and pyramidalis, superior and inferior epigastric arteries and veins, lymphatic vessels and distal portions of the anterior rami of T7-T12.
Inguinal ligament (Poupart ligament)
Thickening of inferior margin of external oblique aponeurosis as an undercurving fibrous band with a free edge that spans between ASIS and pubic tubercle.
Pyramidialis
Small insignificant triangular muscle. Absent in approximately 20% of people. Lies anterior to inferior part of rectus abdominis. Attaches to anterior surface of pubis and the anterior pubic ligament, ends in linea alba.