Anterior muscles of Trunk

Question 1

Pectoralis major

Answer 1

O - Sternum, clavicle and first six ribs (3 heads)
I - Proximal humerus
A - Adducts and flexes the humerus

Question 2

Internal Intercostal muscles

Answer 2

O - Superior border of 2nd to 12th ribs
I - inferior border of the ribs above 1-11
A - Depresses the ribs, aids in forced
expiration

Question 3

External Intercostal muscles

Answer 3

O - lower border of ribs 1-11
I - Upper border of ribs below 2-12
A - Elevates the ribs, aiding in normal Inhalation

Question 4

Diaphragm

Answer 4

O - Xiphoid process, lumbar vertebrae
I - Central tendon that blends with the anterior longitudinal ligament of the vertebral column
A - Expands the thoracic cavity Compresses the abdominal cavity

Question 5

Serratus anterior

Answer 5

O - from the first to ninth ribs
I - inserts into superior angle, medial border, inferior angle of scapula
A - pulls the scapula forward around the thorax

Question 6

Pectoralis minor

Answer 6

O - anterior third to fifth ribs
I - medial border and coracoid process of scapula
A - stabilization, depression, abduction or protraction, internal rotation and downward rotation of the scapula