Muscles of Vertebral Column, Superficial Back, Deep Back and Suboccipital Region Flashcards
Latissimus dorsi Origin? Insertion? Innervation? Action?
O: Spinous processes of T7-T12, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs.
I: Floor of intertubercular sulcus (groove) of humerus
Innervation: Thoracodorsal nerve (C6-C8)
Action: Internal rotation, adduction, extension, respiration (Cough muscle), raises body during climbing
Trapezius Origin? Insertion? Innervation? Action?
O: Medial third of superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-T12 vertebrae.
I: Lateral third of clavicle, acromion, and spine of scapula.
Innervation: Spinal accessory nerve (CN11 - motor fibers) C3-C4 of cervical plexus (pain and proprioceptive fibers).
Action:
Descending - elevates scapula
Ascending - depresses scapula
Transverse (or all parts together) - retracts scapula; descending and ascending parts act together to rotate glenoid cavity superiorly
Splenius capitis origin? Insertion? Innervation? Action?
O: Arises from nuchal ligament and spinous processes of C7-T3 or T4
I: Mastoid process, lateral superior nuchal line
Innervation: Posterior rami of spinal nerves
Action:
Alone-> Laterally flex neck and rotate head to side of active muscles
Together-> Extend head and neck
Splenius cervicis origin? Insertion? Innervation? Action?
O: Arises from nuchal ligament and spinous processes of C7-T3 or T4
I: Tubercles of transverse processes of C1-C3 vertebrae
Innervation: Posterior rami of spinal nerves
Action:
Alone-> Laterally flex neck and rotate head to side of active muscles
Together-> Extend head and neck
Levator scapulae Origin? Insertion? Innervation? Action?
O: Posterior tubercles of transverse processes of C1-C4
I: Medial border of scapula superior to root of spine.
Innervation: Dorsalscapular nerve (C5) and cervical nerves (C3-C4)
Acton: Elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula.
Longissimus capitis, cervicis, and thoracis Origin? Insertion? Innervation? Action?
O: Arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament.
I: Fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions and to mastoid process of temporal bone.
Innervation: Posterior rami of spinal nerves
Action:
Bilateral-> Extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers
Unilateral-> Laterally flex vertebral column
Rhomboid minor Origin? Insertion? Innervation? Action?
O: Nuchal ligament; spinous processes of C7 and T1 vertebrae
I: Triangular area at medial end of scapular spine.
Innervation: Dorsal scapular nerve (C4-C5)
Action: Retracts scapula and rotates it to depress glenoid cavity; fixes scapula to thoracic wall.
Spinalis capitis, cervicis, and thoracis Origin? Insertion? Innervation? Action?
O: Arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament.
I: Fibers run superiorly to spinous processes in upper thoracic region and to cranium.
Innervation: Posterior rami of spinal nerves
Action:
Bilateral-> Extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers
Unilateral-> Laterally flex vertebral column
Illiocostalis cervicis, thoracis and lumborum Origin? Insertion? Innervation? Action?
O: Arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament.
I: fibers run superiorly to angles of lower ribs and cervical transverse processes.
Innervation: Posterior rami of spinal nerves
Action:
Bilateral-> Extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers
Unilateral-> Laterally flex vertebral column
Rectus capitis posterior major Origin? Insertion? Innervation? Action?
O: C2 spinous process
I: Lateral part of the inferior nuchal line of occipital bone.
Innervation: Suboccipital nerve (C1) (posterior ramus)
Action: Bilateral-> extends head Unilateral-> rotates head to same side
Multifidus Origin? Insertion? Innervation? Action?
O: Arise from posterior sacrum, posterior superior iliac spine of ilium, aponeurosis of erector spinae, sacro-iliac ligaments, mammillary processes of lumbar vertebrae, transverse processes of T1-T3 and articular processes of C4-C7.
I: Thickest in lumbar region, fibers pass obliquely superomedially to entire length of spinous processes of vertebrae located 2-4 segments superior to origin.
Innervation: Posterior rami of spinal nerve
Action: Unilateral contraction rotates to contralateral side; stabilizes vertebrae during local movements of vertebral column
Semispinalis thoracis, cervicis, and capitis Origin? Insertion? Innervation? Action?
O: Arise from transverse processes of C4-T10 vertebrae
I: Fibers run superomedially to occipital bone and spinous process in upper thoracic and cervical regions, spanning 4-6 segments.
Innervation: Posterior rami of spinal nerve
Action: Extends head and thoracic and cervical regions of vertebral column and rotates them contralaterally.
Rectus capitis posterior minor Origin? Insertion? Innervation? Action?
O: C1 posterior tubercle
I: Medial third of inferior nuchal line.
Innervation: Suboccipital nerve (C1) (posterior ramus)
Action: Bilateral-> extends head Unilateral-> rotates head to same side
Rotatores longi and brevis Origin? Insertion? Innervation? Action?
O: Arise from transverse processes of vertebrae; are best developed in thoracic region
I: Fibers pass superomedially to attach to junction of lamina and transverse process or spinous process of vertebrae immediately (brevis) or 2 segments (longus) superior to vertebra of origin.
Innervation: Posterior rami of spinal nerve
Action: May function as organs of proprioception; possibly stabilize vertebrae and assist with local extension and rotatory movements of vertebral column
Obliquus capitis superior Origin? Insertion? Innervation? Action?
O: C1 transverse process
I: Occipital bone between the superior and inferior nuchal lines.
Innervation: Suboccipital nerve (C1) (posterior ramus)
Action: Bilateral-> extends head Unilateral-> tilts head to same side, rotates to opposite side
