What muscle is primarily supplied by the thoracodorsal nerve?

The thoracodorsal nerve is primarily responsible for the innervation of the latissimus dorsi muscle. This muscle plays a critical role in various movements of the shoulder, including extension, adduction, and internal rotation of the arm. The thoracodorsal nerve arises from the posterior cord of the brachial plexus and specifically targets the latissimus dorsi, facilitating its function in upper limb movements.

The infraspinatus muscle, while important for shoulder stability and external rotation, is innervated by the suprascapular nerve. The subscapularis muscle has a dual innervation from both the upper and lower subscapular nerves, emphasizing that each of these muscles has distinct nerve supplies that allow for their specific actions. The teres major, although it has a similar function to the latissimus dorsi, is innervated by the lower subscapular nerve. Understanding these specific nerve supplies is critical for comprehending the functional anatomy of the shoulder region and the implications for surgical procedures or nerve injuries.