College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which muscle originates on ribs 3-5 and inserts on the coracoid process?

1. coracobrachialis

2. biceps brachii

3. serratus anterior

4. pectoralis minor

The correct answer is: pectoralis minor

The muscle that originates on ribs 3-5 and inserts on the coracoid process is indeed pectoralis minor. This muscle plays a crucial role in stabilizing the scapula by drawing it anteriorly and inferiorly against the thoracic wall. Its attachment to the coracoid process, which is a projection of the scapula, allows it to assist with movements involving the shoulder and arm, particularly when performing actions that require the scapula to move or rotate. The other muscles listed do not have this specific origin and insertion. For instance, coracobrachialis originates on the coracoid process and primarily acts on the humerus, while biceps brachii originates from two points on the scapula and predominantly performs flexion of the elbow and shoulder. Serratus anterior, while it plays a vital role in scapular motion, originates from the upper ribs but does not attach to the coracoid process. Thus, the unique connection of pectoralis minor to the ribs and the coracoid process makes it the correct answer to the question posed.