In a Subclan aery block at the outer border of 1st rib, all of the following aeries help in maintaining the circulation to upper limb except?: (A) Subscapular aery, (B) Superior thoracic, (C) Thyrocervical trunk, (D) Suprascapular aery
Answer is B. A rich anastomoses exists around the scapula between branches of subclan aery (first pa) & the axillary aery (third pa).This anastomoses provides a collateral circulation through which blood can flow to the limb when the distal pa of subclan aery or the proximal pa of axillary aery is blocked.