PT 794 Cervical Muscles Flashcards
Sternocleidomastoid m.
(SUPERFICIAL neck muscle)
O: lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line
i:
-Sternal head: anterior manubrium of sternum
-Clavicular head: superior medial third of clavicle
Inn: spinal accessory nerve (CN XI, motor); C3 and C4 nerves (pain and proprioception)
A:
-Unilateral contraction: lateral flexion of head to SAME side & rotation AWAY to opposite side
-Bilateral contraction: PROTRACTION
1. Extends neck at ATLANTO-OCCIPITAL joints (posterior fibers) 2. Flexes cervical vertebrae so that chin goes to manubrium (anterior fibers) OR 3. Extends superior cervical vertebrae while flexing inferior vertebrae
also assists with deep respiration with cervical vertebrae fixed
Trapezius m.
(SUPERFICIAL neck muscle)
O: medial 1/3 of nuchal line, external occipital protuberance, C7-T12, lumbar and sacral spinous processes
i: lateral 1/3 of clavicle, acromion, and spine of scapula
Inn: spinal accessory nerve (CN XI; motor); C3 & C4 nerves (pain and proprioception)
A: elevates, retract and upwardly rotates scapulae
-Descending (superior) fibers: elevate scapulae/shoulders, maintain level of shoulders against gravity/resistance
-Transverse (middle) fibers: retract scapulae
-Ascending (lower) fibers: depress scapulae/shoulders
-Descending and Ascending fibers together: upwardly rotate scapula
With shoulders fixed:
-bilateral contraction: extends neck
-unilateral contraction: lateral flexion to SAME side and rotation away
Longus Colli m.
(prevertebral: anterior vertebral muscles)
O: anterior tubercle of C1 vertebra (atlas); bodies of C1-C3 and transverse processes of C3-C6 vertebrae
i: bodies of C5-T3 vertebrae; transverse processes of C3-C5 vertebrae
Inn: anterior rami of C spinal nerves
A: flexes neck (OA) with rotation (torsion at AA) to opposite side if acting unilaterally
Longus capitis m.
(prevertebral: anterior vertebral muscles)
O: basilar part of occipital bone
i: anterior tubercles of C3-C6 transverse processes
Inn: anterior rami of C spinal nerves
A: flex head (at OA)
Rectus capitis anterior m.
O: base of cranium, just anterior to occipital condyle
i: anterior surface of lateral mass of atlas
inn: branches from loop between C spinal nerves
a: flex head
Splenius capitis m.
O: spinous processes of T1-T6
i: lateral aspect of mastoid process and lateral third of superior nuchal line
inn: POSTERIOR rami of middle spinal nerves
a: laterally flexes head and rotates head and neck to same side acting bilaterally, extends head and neck
Splenius m.
O: spinous processes of T1-T6
i:
-Cervicis: C1-C4 transverse processes
-Capitius: fibers run superolaterally to mastoid process (lateral aspect) and lateral 1/3 of superior nuchal line
Inn: posterior rami of cervical spinal nerves
A: ipsilaterally: laterally flexion and rotattion of head and neck to SAME side. Bilaterally: extends head and neck (lower and upper cervical spine)
Levator scapulae m.
(prevertebral: lateral vertebral muscles)
O: posterior tubercles of transverse processes C2-C6 vertebrae
i: superior part of medial border of scapula
Inn: dorsal scapular nerve C5 and cervical spinal nerves C3 and C4
A: downward rotation of scapula and tilts glenoid cavity inferiorly by rotating scapula, elevation of scapula + lateral flexion to SAME side (neck)
Middle Scalene m.
(prevertebral: lateral vertebral muscles)
O: posterior tubercles of transverse processes of C5-C7
i: superior surface of 1st rib; posterior to groove for subclavian artery
Inn: anterior rami of cervical spinal nerves
A: ipsilateral lateral neck; elevates 1st rib during forced inspiration
Posterior scalene m.
(prevertebral: lateral vertebral muscles)
O: posterior tubercles of transverse processes of C5-C7
i: external border of 2nd rib
Inn: anterior rami of cervical spinal nerves
A: ipsilateral lateral neck flexion; elevates 2nd rib during forced inspiration
Scalenes action together
unilaterally: ipsilateral lateral flexion, contralateral rotation
bilaterally: neck flexion
Semispinalis m.
(Transversospinalis)
O: transverse process of C4-T12 vertebrae
i: thoracic, cervicis, capitis; fibers run superomedially to occipital bone and [superior] spinous processes in thoracic and cervical regions, spanning 4-6 segments
Inn: posterior rami of spinal nerves
A: bilaterally: extends head and thoracic and cervical regions of vertebral column. Unilaterally: contralateral rotation of head and cervical/throacic spine with ipsilateral lateral flexion
Rectus Capitis Posterior Major m.
(suboccipital muscles)
O: spinous process of C2
i: lateral part of inferior nuchal line of occipital bone
Rectus capitis posterior minor m.
(suboccipital muscles)
O: posterior tubercle of posterior arch of C1 vertebrae (atlas)
i: medial part of inferior nuchal line of occipital bone
Obliquus capitis inferior m. (suboccipital muscles)
O: posterior tubercle of posterior arch of C2 vertebrae (axis)
i: Transverse process of C1 vertebrae (axis)
