Principal Muscles of Anterolateral Abd Wall

Question 0

internal oblique

Answer 0

O: thoracolumbar fascia, ant 2/3 of iliac crest, CT deep to inguinal
canal
I: inf borders of ribs 10-12, linea alba, pubis via conjoint tendon
N: thoraco-abdominal nerves (ant rami T7-T11), first lumbar nerve
A: compress and support abdominal viscera
flex and rotate trunk

Question 1

external oblique

Answer 1

O: ext surfaces of ribs 5-12
I: linea alba, pubic tubercle, ant 1/2 of iliac crest
N: thoraco-adbominal nerves (ant rami of T7-T11)
subcostal nerve
A: compress and support abd viscera
flex and rotate trunk

Question 2

transversus abdominis

Answer 2

O: internal surfaces of costal cartilages 7-12, thoracolumbar
fascia, iliac crest, CT deep to inguinal ligament
I: linea alba w/ aponeurosis of internal oblique, pubic crest,
pectin pubis via conjoint tendon
N: thoraco-abdominal nerves (T7-T11)
first lumbar nerve
A: compresses and supports abd viscers

Question 3

rectus abdominis

Answer 3

O: pubic symphysis and pubic crest
I: xiphoid process and costal cartilages 5-7
N: thoraco-abdominal nerves (ant rami of inf 6 thoracic nerves)