3 parts-  iliocostalis, longissimus, and spinalis

Origin:  by a broad tendon by iliac crest, posterior sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament

Insertion:  ribs, cervical vertebra, mastoid process of temporal bone, nuchal ligament

Action:  bilateral- extends vertebral column and head, as back is flexed, control movement via eccentric contraction    unilateral-- laterally flex vertebral column

Nerve: posterior rami of spinal nerves

Tendon:

Origin: sacrum, ilium, and transverse processes

Insertion: spinous processes

function: stabilizes vertebrae during local movements of the vertebral column, extends and rotates head, neck, and trunk

Nerve:  posterior rami of the spinal nerve

Artery:

Tendon:

origin: spinous processes T7-T12, related interspinous ligaments, thoracolumbar fascia, iliac crest, ribs 9-12

Insertion: floor of the intertubercular groove of the humerus

Innervation-  thoracodorsal nerve

Artery- thoracodorsal artery

action-  adducts, extends, and medially rotates humerus; raises body towards arms when climbing

origin: spinous processes T11-L2

Insertion:  inferior borders of 8th to 12th ribs near the angles

Nerves:  anterior rami T9- T12 thoracic spinal nerves

Action: depress ribs (proprioception)

Includes semispinalis multifidus, rotatores brevis and rotatores longus 

Origin: transverse processes

Insertion: spinous processes of more superior vertebrae

Nerves posterior rami of spinal nerves

kyphosis-  increased thoracic curvature (osteoporosis)

lordosis-  increased lumbar curvature (weakened trunk musculature)

scoliosis-  lateral due to:

1.  unequal growth of the vertebral column

2.  assymetric paralysis or muscle weakness

3.  pathologica erosion of vertebral bodies

Intervertebral discs

Between vertebrae, 1/4 length of vertebrae, shock absorber

1.  Nucleus pulposus- equalizes pressure to absorb shock

-reticular and collagenous fibers in mucoid material

-remnant of embryonic notochord

-can herniate through AF, impinging on spinal nerve roots

2.  Anulus fibrosis

-made of cocentric layers of fibrous tissus and fibrocarilage

-binds vertebral column together, retains NP, permits limited movement.  

-runs from skull (occipital bone) to the saccrum on the anterior surface of the vertebral bodies and IV discs

-widens as it descends to maintain stability of the joints

-1.  limits extension of vertebral column

2.  supports annulus fibrosis anteriorly

3.  resists gravitational pull

-interconnects the vertebral bodies and IV discs posteriorly

-narrows as it descends

1.  limits flexion of vertebral column

2.  supports posterior aspect of the vertebral bodies and AF

3.  resists gravitational pull

1.  connects laminae of two adjacent vertebrae

2.  functions to maintain the upright posture

pierced during lumbar puncture and spinal tap

-innermost meningeal layer; cannot be dissected from the spinal cord

-enmeshes blood vessels on the surfaces of the the spinal cord

-filmy transparent layer connected to pia mater by web-like trabeculations

-forms subarachnoid space, which is filled with cerebrospinal fluid

-extends to 2nd sacral vertebral level

-lumbar cistern= enlarnged subarachnoid space btwn L1 and S2

-tough, fibrous, outermost layer

-subdural space= potential space btwn arachnoid and dura mater, goes to S2, contains minimal fluid to moisten the membrane

-epidural space= external to the dura mater. contains internal vertebral venous plexus and epidural fat. 

-flexion

-extension

-lateral bending

-rotation

surgical excision of one or more spinous processes and supporting vertebral laminae

Used to:

1. gain access to the vertebral canal and expose spinal cord/roots

2.  relieve pressure on spinal cord or nerve roots caused by:

-tumor

-herniated IV disc

-bony hypertrophy