n. one of four paired muscles of the neck (scalenus anterior, medius, minimus, and posterior), extending from the cervical (neck) vertebrae to the first and second ribs. They are responsible for raising the first and second ribs in inspiration and for bending the neck forward and to either side.
(thoracic outlet syndrome) the group of symptoms caused by compression of the subclavian artery and the lower roots of the brachial plexus against the fibrous and bony structures of the outlet of the upper thoracic vertebrae. Loss of sensation, wasting, and vascular symptoms may be found in the affected arm, which may also be painful.... scalenus syndrome
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