The pectoralis major originates from which of the following?

• A. Lateral border of the scapula
• B. Medial half of the clavicle, sternum, and cartilage of the first through sixth ribs
• C. Coracoid process
• D. Xiphoid process

Answer: (B)

Pectoralis major has two main origin regions that span the upper chest: the medial half of the clavicle and the sternum plus the costal cartilages of the first through sixth ribs. This broad, double-headed origin allows the muscle to attach to the humerus and produce actions like moving the arm inward (adduction) and turning it inward (medial rotation), as well as assisting with flexion when the clavicular part is active. The other options point to origins of different muscles: the lateral border of the scapula is associated with muscles like teres minor, the coracoid process is a site for the short head of biceps and coracobrachialis, and the xiphoid process is not a common origin for the pectoralis major.