1. adj. accessory or secondary. 2. n. a branch (e.g. of a nerve fibre) that is at right angles to the main part.
1. an alternative route provided for the blood by secondary vessels when a primary vessel becomes blocked. 2. the channels of communication between the blood vessels supplying the heart. At the apex of the heart, where the coronary arteries form *anastomoses, these are very complex.... collateral circulation
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