Unit 3 - Thorax, Abdomen, Pelvis, and Perineum: Anterolateral Abdominal Wall Muscles (Ex. III)

Question 1

internal oblique

Answer 1

O: deep layer of thoracolumbar fascia; intermediate line of iliac crest; ASIS; iliopsoas fascia
I: lower borders of ribs 10-12; A and P layers of linea alba
Inn: intercostal nn. (T7-T12); iliohypogastric n.; ilioinguinal n.
A: ipsilaterally laterally flexes trunk and contralaterally rotates; bilaterally flexes trunk, compresses abdomen, and stabilizes pelvis

Question 2

transversus abdominis

Answer 2

O: inner surfaces of costal cartilages of ribs 7-12; deep layer of thoracolumbar fascia; iliac crest; inner lip of ASIS; iliopsoas fascia
I: linea alba; pubic crest
Inn: intercostal nn. (T7-T12); iliohypogastric n.; ilioinguinal n.
A: ipsilaterally rotates trunk; bilaterally compresses abdomen

Question 3

external oblique

Answer 3

O: outer surface of ribs 5-12
I: linea alba; pubic tubercle; A iliac crest
Inn: intercostal nn. (T7-T12)
A: ipsilaterally laterally flexes trunk and contralaterally rotates; bilaterally flexes trunk, compresses abdomen, and stabilizes pelvis