trapezius

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tra·pe·zi·us (mus·cle)

[TA]
extrinsic (thoracoappendicular) muscle of shoulder; origin, medial third of superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of seventh cervical and the thoracic vertebrae and corresponding supraspinous ligaments; insertion, lateral third of posterior surface of clavicle, anterior side of acromion, and upper and medial border of the spine of the scapula; action, when scapulae are fixed, portions of muscle can act independently: cervical portion elevates scapula, thoracic portion contributes to depression of scapula; upper and lowermost portions act simultaneously to rotate glenoid fossa superiorly; when the entire muscle and especially middle part contracts, the scapulae retract; draws head to one side or backward; nerve supply, motor by accessory, sensory by cervical plexus.
Synonym(s): musculus trapezius [TA], cowl muscle

trapezius

(trə-pē′zē-əs)
n. pl. trapezi·uses
Either of two large flat triangular muscles running from the base of the occiput to the middle of the back that support and make it possible to raise the head and shoulders.

trapezius

[trəpē′zē·əs]
Etymology: Gk, trapezion, small table
a large, flat, triangular superficial muscle of the shoulder and upper back. It arises from the occipital bone, the ligamentum nuchae, and the spinous processes of the seventh cervical and all the thoracic vertebrae. It acts to rotate the scapula upward; adduct, raise, or lower the shoulder; and retract the shoulder.
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Trapezius

tra·pe·zi·us mu·scle

(tră-pē'zē-ŭs mŭs'ĕl)
Origin, medial third of superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of seventh cervical and the thoracic vertebrae and corresponding supraspinous ligaments; insertion, lateral third of posterior surface of clavicle, anterior side of acromion, and upper and medial border of the spine of the scapula; action, when scapulae are fixed, portions of muscle can act independently: cervical portion elevates scapula, thoracic portion contributes to depression of scapula; upper and lowermost portions act simultaneously to rotate glenoid fossa superiorly; when the entire muscle and especially its middle part contracts, the scapulae retract; draws head to one side or backward; nerve supply, motor by accessory, sensory by cervical plexus.
Synonym(s): musculus trapezius [TA] , trapezius.
Figure 1: Efferent nerve pathways from the brainstem and spinal cord. Shown on the right: somatic, to skeletal muscles. Shown on the left: autonomic. B brain stem, C cervical, T thoracic, L lumbar, S sacral segments of the spinal cord. (Red shaded regions are those with no autonomic outflow.)

trapezius

large, triangular, superficial muscle on each side of the upper back, its origin extending in the midline from the base of the skull down to the spine of the lowest thoracic vertebra. From there its fibres converge towards the shoulder, and partly over it, round the side of the lower neck, to be inserted in a continuous line into the outer end of the clavicle and the spine of the scapula. The tone of the two muscles keeps the shoulders braced and they act with the scapular spine as a lever when lifting the arms at the shoulder. Figure 1.