Muscle | Body wall layer | Action |
Pectoralis Minor | anterior, superior surfaces of rib 3-5 | coracoid process of scapula |
Pectoralis Major | cartilages of ribs 2-6 body of sternum and inferror medeal protion of clavical. | crest of grater tubacle and lateral lip of intertubericular groove of humerus |
Cervical Longus colli | Subvertebral | Flexes the neck and rotates it to the opposite side, flexes the head. |
Sternalis | Ventral | Nothing, assists with rib movement when present. |
Intercostals | Lateral | Move and depress the ribs. |
Diaphragm | Lateral | Increases the volume of the thoracic cavity in inspiration. |
Thoracic Longus colli | Subvertebral | Flexes the neck and rotates it to the opposite side. |
Rectus abdominis | Ventral | Flexes the lumbar vertebral column, helps compress the abdominal cavity. |
External oblique | External Lateral | Helps compress the abdominal cavity, compress and depress the lower thoracic cavity to aid in expiration, rotates trunk to opposite side. |
Internal oblique | Intermediate(middle) lateral | Strong compressor of the abdominal cavity, rotates trunk to the same side. |
Transversus abdominis | Internal Lateral | Compresses the abdominal cavity. |
Quadratus lumborum | Internal Lateral(posterior) | Laterallly flexes the vertebral column, extends lumbar verebrae. Fixes 12th rib to stabilize diaphragm attachments during inspiration. |
Psoas major | Subvertebral | Extends the lumbar vertebral column (deepening the lumbar curve) to maintain posture. Powerful flexor of the hip. |
Diaphragm | Xiphoid process cartilages of ribs 4-10 and anterior surfaces of lumbar vertebrae. | cnetral tendinous sheet. |
External oblique | External and inferior borders of rib 5-12 | linea alba and iliac crest |
Internal oblique | lumbodorsal fascia and iliac crest | Inferior fibs, xiphoid process and linea alba. |
Transversus abdominis | Cartilages of ribs 6-12 Iliac crest and lumbodorsal fascia. | Linea alba and pubis |