Muscles of the Spine Flashcards
What are the origins and insertions of trapezius?
O: Medial 1/3rd superior nuchal line of occipital bone, external occipital protuberance, ligamnetum nuchae, C7-T12 spinous processes and supraspinous processes
I: Upper Fibres - posterior border of lateral 1/3rd clavicle. Middle fibres - medial margin of acromion & superior lip of crest of spine of scapula.
Lower fibres - tubercle at medial end of spine of scapula
Direction of fibres for trapezius
upper fibres run down and lateral
middle fibres run horizontally
lower fibres run superiorly and laterally
what is the nerve supply for trapezius
spinal acessory nerve - C2, C3, C4
what is the action of trapezius?
upper fibres - elevate shoulder girdle, extend Cx spine bilaterally & side flexion of Cx spine unilaterally (with ROI)
middle fibre - retract shoulder girdle
lower fibres - depress shoulder girdle
together - cause lateral rotation of scapula
what are the attachments of sternomastoid?
O: sternal head - anterior surface of manubrium, clavicular head - upper surface of medial third of clavicle
I: mastoid process and lateral third of superior nuchal line
nerve supply to sternomastoid?
cranial accessory nerve 11
anterior primary rami C2 and C3
what is the action of sternomastoid?
flexion, lateral flexion to the same side and rotation to the opposite side
what are the attachments of anterior scalene?
O: transverse process of C3-6
I: scalene tubercle on inner border of 1st rib
nerve supply of anterior scalene?
anterior primary rami C4, 5 and 6
what are the function of anterior scalenes?
lateral flexion to the same side
and work with ROI to lift ribs in forced inhalation
neck flexion
what are the attachments of scalenus medius?
O: transverse process of C1-7
I: upper surface of 1st rip
nerve supply of scalenus medius?
anterior primary rami C3-8
what are the attachments of scalenus posterior?
O: transverse process C4-6
I: outer surface of 2nd rib
nerve supply of scalenus posterior?
anterior primary rami C6,C7, C8
attachments of levator scapulae?
O: transverse process C1-4
I: upper part medial border of scapula
