Final answer:
Circumscapular anastomosis involves a network of arteries surrounding the scapula, which is linked to the axillary artery as it provides blood to regions near the head of the humerus and eventually becomes the brachial artery.
Step-by-step explanation:
The circumscapular anastomosis refers to the network of arteries surrounding the scapula and providing blood supply to the region. This anastomosis is indirectly related to the axillary artery, which is a continuation of the subclavian artery as it penetrates the body wall and enters the axillary region. The axillary artery supplies blood to the region near the head of the humerus, including via the humeral circumflex arteries. The majority of the artery continues into the brachium and becomes the brachial artery. This extensive network of blood vessels, including the circumscapular anastomosis, ensures that the upper limb receives an adequate blood supply, even if one pathway is obstructed.