Oblique & Rectus (Anterior)

Question 1

Rectus abdominis

Answer 1

ORIGIN: pubic crest, pubic symphysis

INSERTION: pubis, cartilages of ribs 5-7, xiphoid process

ACTION: flexion of spine, compression of abdominal viscera

INNERVATION: spinal nerves (T 7-T 12)

Question 2

External oblique

Answer 2

ORIGIN: sternum, ribs (5-12)

INSERTION: linea alba, iliac crest

ACTION: -Bilaterally: flexion of the spine, compress the abdomen;
-Unilaterally: flexes trunk to same side, rotates to opposite side

INNERVATION: lower intercostal, ilioinguinal nerves

Question 3

Internal oblique

Answer 3

ORIGIN: iliac crest, lumbodorsal fascia

INSERTION: inferior ribs, linea alba

ACTION: flexes spine, compresses abdomen, depresses ribs

INSERTION: lower intercostal, ilioinguinal nerves

Question 4

Transverse abdominis

Answer 4

ORIGIN: lateral inguinal ligament, inner iliac crest

INSERTION: linea alba, pubis

ACTION: compression of abdomen

INNERVATION: first lumbar nerve (T 7- L1)iliohypogastric (T12-L1)ilioinguinal (T12-L1)