Which of the following is NOT a branch of the third part of the axillary artery?

The axillary artery is divided into three parts, with the third part continuing to give off branches that supply the shoulder and upper arm. The branches from the third part include the posterior circumflex humeral artery, the anterior circumflex humeral artery, and the subscapular artery.

The posterior and anterior circumflex humeral arteries primarily supply the deltoid muscle and the shoulder area, while the subscapular artery branches off to supply regions such as the subscapularis muscle and parts of the back. Each of these branches plays a significant role in the vascularization of the shoulder and surrounding structures.

The brachial artery, in contrast, is not a branch of the axillary artery but rather follows it as a continuation after the axillary artery transitions into the brachial artery at the lower border of the teres major muscle. Therefore, identifying the brachial artery as not being a branch of the third part of the axillary artery is accurate, as it represents a distinct arterial structure that supplies the arm.

By understanding the pathways and branches of the axillary artery, one can appreciate how blood supply is distributed to different regions, which is essential knowledge for surgical and clinical practices in the upper limb.