What is the distal attachment of the pectoralis major muscle?

What is the distal attachment of the pectoralis major muscle?

• A. Medial lip of the intertubercular groove of the humerus
• B. Lateral lip of the intertubercular groove of the humerus
• C. Greater tubercle of the humerus
• D. Proximal radius

Answer: (B)

The pectoralis major muscle is a large muscle located in the chest that is primarily responsible for adduction and medial rotation of the shoulder joint. Its fibers converge to a common distal attachment on the humerus. The correct distal attachment of the pectoralis major is found at the lateral lip of the intertubercular groove of the humerus. This attachment is significant because it allows the muscle to effectively exert its force during movements of the arm, including pushing and lifting activities. Understanding the anatomical position of this muscle and its attachment points is crucial for comprehending how it functions in conjunction with other muscles during upper body movements. The placement on the lateral lip of the intertubercular groove ensures that the pectoralis major contributes to shoulder flexion, adduction, and internal rotation, which are essential motions in many daily activities and sports. In contrast, the other options presented do not accurately reflect the insertion point of the pectoralis major, as they either refer to different locations on the humerus or involve bones that the pectoralis major does not attach to, such as the proximal radius. Thus, the clarity surrounding the muscle's anatomy and its specific attachment is key in understanding its role in the musculoskeletal system.

The pectoralis major muscle is a large muscle located in the chest that is primarily responsible for adduction and medial rotation of the shoulder joint. Its fibers converge to a common distal attachment on the humerus. The correct distal attachment of the pectoralis major is found at the lateral lip of the intertubercular groove of the humerus. This attachment is significant because it allows the muscle to effectively exert its force during movements of the arm, including pushing and lifting activities.

Understanding the anatomical position of this muscle and its attachment points is crucial for comprehending how it functions in conjunction with other muscles during upper body movements. The placement on the lateral lip of the intertubercular groove ensures that the pectoralis major contributes to shoulder flexion, adduction, and internal rotation, which are essential motions in many daily activities and sports.

In contrast, the other options presented do not accurately reflect the insertion point of the pectoralis major, as they either refer to different locations on the humerus or involve bones that the pectoralis major does not attach to, such as the proximal radius. Thus, the clarity surrounding the muscle's anatomy and its specific attachment is key in understanding its role in the musculoskeletal system.