scalene muscle

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of three muscles on each side of the neck that originate at the cervical vertebrae and insert into either the first or second ribs, serving to bend and rotate the neck and assist breathing by raising the first and second ribs.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy any of the three pairs of muscles on each side of the neck that are involved in moving the neck, and in breathing

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any of four pairs of muscles extending from the cervical vertebrae to the second rib; involved in moving the neck and in breathing