Ventral side muscles

Pectoralis major

Origin- Clavicle

Insertion-humerus
Action- arm flexion

Serratus anterior

Origin-ribs

Insertion -scapula
Action-abduction of scapula

Internal intercostals

Origin- superior border of rib below

Insertion-inferior border of rib above
Action-  pulls ribs together to depress

Diaphragm

Origin-sternum

Insertion -central tendon
Action-inspiration

Rectus abdominis

Origin-pubic bone

Insertion -xiphoid process of the sternum
Action-rotates vertebral cloumn

External obliques

Origin-ribs

Insertion -pubic bone
Action-compress the abdominal wall

Internal obliques

Origin-ilium

Insertion- pubic bone
Action- compress abdominal wall

Transverse abdominis

Origin-ilium

Insertion- pubic bone
Action-compress abdominal contents

Pectoralis minor

Origin-ribs

Insertion -coracoid process of the scapula
Action-inferior scapula movement

External intercostals

Origin- inferior border of ribs above

Insertion -superior border of ribs below
Action-pulls ribs together to elevate