O I A n. Human anatomy *2nd half*

Transversus thoracic muscle

O- posterior aspect of sternum

I- mid clavicular regions of ribs

A- depress rib

n.- intercostal n

Subcostal muscles

O- lower ribs near sternal angles

I- skip 1-2 layers and insert on ribs above

A- depress ribs

n.- intercostal n

External oblique

O- (sup/lat)external surfaces of ribs 5-12

I- (inf/med) Linea alba, pubic tubercle, anterior ½ iliac crest

A- flex(bilateral) and rotate trunk(unilateral)

    Compress and support/stabilize abdominal viscera

*can compromise gastrointestinal issues!!

n.- thoracoabdominal n.: ventral ramii T7-11 and Subcostal n.

Internal oblique

O- thoracolumbar fascia, anterior ⅔ of iliac crest, connective tissue deep to lat ½ of inguinal ligament

I- inferior borders of ribs 10-12, linea alba, pectin pubis (conjoint tendon)

A- flex(bilateral) and rotate trunk(unilateral)

    Compress and stabilize abdominal viscera

n.- thoracoabdominal n.:  ventral ramii T6-T12 and L1 n.

rectus abdominus

O- pubic symphysis, pubic crest

I- xyphoid process, costal cartilage of ribs 5-7

A- flexion, compresses and stabilizes viscera

Controls lumbar lordosis

n.- thoracoabdominal n.: ventral rami t6-t12

Transverse abdominis muscle

O- internal surfaces of costal cartilages 7-12, thoracolumbar fascia, iliac crest, connective tissue deep to alteral ⅓ of inguinal ligament

I- linea alba, pubic crest, pectin pubic (by way of conjoint tendon)

A- ONLY compression and stabilization of viscera

n.- thoracoabdominal n.:  ventral ramii T6-12 and   L1 n.