Oblique And Rectus Muscles: Anterior

Question 1

Rectus abdominis

Answer 1

Origin: pubic crest, pubic symphysis
Insertion: cartilages of ribs 5-7, xiphoid process
Action: bilaterally- flexion of the spine, compression of abdominal viscera
Innervation: spinal nerves (T7-T12)

Question 2

External Obliques

Answer 2

Origin: sternum, ribs (5-12)
Insertion: linea alba, iliac crest
Action: bilaterally- flexion of the spine, compress the abdominal, unilaterally- flexes trunk to same side, rotates to opposite sides
Innervation: lower intercostals, ilioinguinal nerves

Question 3

Internal obliques

Answer 3

Origin: iliac crest, lumbodorsal fascia
Insertion: inferior ribs, linea alba
Action: compresses the abdomen, depresses ribs, flexes spine
Innervation: lower intercostal, ilioinguinal nerves

Question 4

Transverse abdominis- deep to internal oblique

Answer 4

Origin: lateral inguinal ligament, inner iliac crest
Insertion: linea alba, pubis
Action: compression of abdomen
Innervation: first lumbar nerve (t7-l1), iliohypogastric (t12-l1), ilioinguinal (t12-l1)