Final answer:
The scapular anastomosis is composed of the subscapular artery, suprascapular artery, and dorsal scapular artery, which are crucial for providing collateral blood circulation to the shoulder area.
Step-by-step explanation:
The scapular anastomosis refers to the network of arteries that supply blood to the scapular region and shoulder. Three primary arteries make up this anastomosis:
- The subscapular artery, which is a branch of the axillary artery.
- The suprascapular artery, which typically arises from the thyrocervical trunk, a branch of the subclavian artery.
- The dorsal scapular artery, which can originate from either the subclavian artery or the transverse cervical artery.
These arteries provide an important collateral circulation, ensuring consistent blood flow to the upper limb, especially during arm movements that may compress other vessels.