Musculoskeletal Anatomy: Chest and shoulders

Question 1

What are the 2 major chest muscles?

Answer 1

Pectoralis major and minor.

Question 2

What is the origin, insertion and action of pectoralis major?

Answer 2

O: Medial clavicle and along the sternum to the 7th costal cartilage | I: Lateral lip of the intertubercular grove of the humerous. | A: Flexion, adduction and medial rotation of the arm at the glenohumeral joint.

Question 3

What is the origin, insertion and action of pectoralis minor?

Answer 3

O: Rib III to V | I: coracoid process | A: depression of the scapula.

Question 4

What is the origin, insertion and action of serratus anterior?

Answer 4

O: Ribs I to VIII | I: Anteromedial border of the scapula. | A: Protraction of the scapula.

Question 5

What are the muscle(s) of the shoulder?

Answer 5

Deltoid.

Question 6

What is the origin, insertion and action of the deltoid muscle?

Answer 6

O: 1/3 of clavicle, acromion, spine of the scapula | I: deltoid tuberocity | A: anterior fibers - flexion and medial rotation of the arm, middle fibers - abduction of the arm, posterior fibers - extension and lateral rotation of the arm.

Question 7

What is the origin, insertion and action of subscapularis?

Answer 7

O: Subscapular fossa | I: Lesser turbercle of the humerous | A: Medial rotation of the glenohumeral joint.

Question 8

What are the muscle of the rotator cuff?

Answer 8

Supraspinatus, infraspinatus and teres minor.

Question 9

What is the origin, insertion and action of supraspinatus?

Answer 9

O: supraspinus fossa | I: superior facet of the greater turbercle of the humerous | A: initiation of abduction and lateral rotation.

Question 10

What is the origin, insertion and action of infraspinatus?

Answer 10

O: infraspinus fossa | I: middle facet of the greater turbecle of the humerous. | A: lateral rotation of the glenohumeral joint.

Question 11

What is the origin, insertion and action of teres minor?

Answer 11

O: Lateral superior border of the scapula | I: inferior facet of the greater turbercle of the humerous. | A: Lateral rotation of the scapula.

Question 12

What is the origin, insertion and action of teres major?

Answer 12

O: Lateral inferior border of the scapula | I: medial lip of the intertubercular groove of the humerous | A: Extension, adduction and lateral rotation of the arm at the glenohumeral joint.