Deep Back and Spinal Cord

muscles of the deep back

Erector Spinae

-Act on vertebre; both contract=extension spine, 1 side contract=lateral flexion

1. Spinalis

2. Longistimus

3. Iliocostalis

Deep to Erector Spinae

4. Multifidus

deep to multifi…

4. ?

5. Levator Costareum

5 types of vertebrae

-7 servical: neck

-12 thoracic: ribs

-5 lumbar

-(5) sacrum: fused, part of pelvis

-(4) coccyx: tail bone

parts of a typical vertebra

Pictured

-vertebral body

Vertebral Arch (often where muscles attach)

-pedicle: between TP and body

-lamina: between SP and TP

Superior View

-Vertebral foramen: spinal cord

Lateral View

-Superior and inferior vertebral notch: other vertebre articulate

foramens

-intervertebral foramen: exit spinal nerves, R and L side

-inferior vertebral notch and superior vertebral notch

-vertebral foramen: spinal cord

label vertebre

What is the function of the transverse foramina?

vertebral artery

-branch from subclavial a

-to brain

atlas

First cervical vertebra (C 1)

It has no body and leaves a space to accommodate the dens of the axis. Superior articular surfaces articulate with occipital condyles – “YES”movement of the head

*articulates w/ skull

axis

Second cervical vertebra (C 2)

It has a tooth-shaped process, the dens (odontoid process), which articulates with the atlas as a pivot joint – “NO” movement of the head

__has a prominent spinous process

C7

*good for palpation

identify features of a thoracic vertebra

-articulates w/ ribs (facets)

-coronal/verticle plane

-spinous process points inf

identify features of a lumbar vertebra

-very large

-articular process in sagittal plane

-SP ponts post

sacrum and coccyx

-fused together; part of pelvis

Cervical vs. Thoracic vs. Lumbar Vertebrae

CERVICAL

Transverse foramen

Bifid spinous process (most of them)

Articular facets oriented in transverse plane

THORACIC

Costal facets (*ribs articulate)

Articular facets oriented in coronal plane

Spinous process directed inferiorly

LUMBAR

Massive size (*large body, most weight bearing)

Articular facets oriented in para-sagittal plane

Spinous process directed posteriorly

list joints of the vertebral column

1.  Joints of the vertebral bodies

a.Intervertebral discs

b.Uncovertebral joints

c.Ligaments – anterior and posterior longitudinal ligaments

2.  Joints of the vertebral arches – facet joints   (zygapophyseal joints)

3.  Craniovertebral joints

a.Atlanto-occipital joints

b.Atlanto-axial joints

4.  Accessory ligaments of intervertebral joints

a.Ligamentum flavum

b.Interspinous ligament

c.Supraspinous ligament

d.Ligamentum nuchae (nuchal ligament)

e.Intertransverse ligaments

intervertebral disc

-Annulus fibrosus – outer portion; composed of fibrocartilage and fibrous connective tissue

-Nucleus pulposus –  inner portion; semigelatinous fluid with very few, if any, cells (*squisher, gel-like)

-Note: NO intervertebral disc between atlas and axis

-The IV disc is reinforced anteriorly and anterolaterally by the anterior longitudinal ligament.

-The IV disc is reinforced posteriorly by the posterior longitudinal ligament.

-The IV disc is not reinforced posterolaterally.

“WHIPLASH” INJURY

-Results from severe hyperextension of the neck, as occurs in during rear-end motor vehicle collisions, especially when the head restraint is too low

-Anterior longitudinal ligament is severely stretched and may be torn

-May injure posterior parts of the vertebral arches and their processes

-Herniation of the nucleus pulposus is almost always in a
___direction

-Practice Question: A 70-year-old female complaining of lower back pain is diagnosed with a herniated disc at the level of L4-5.  Which spinal nerve(s) is/are most likely compressed?

-Herniation of the nucleus pulposus is almost always in a
posterolateral direction,  passing through a rupture of the annulus fibrosus.

-may lean to opposite side to relieve compression of nerve

*IVD impinge on SN

Practice Question

-L5

Articular facets (zygopophyses)

joints of C1 and C2

ligaments of C1 and C2

Ligaments of intervertebral joints

•Ligamentum flavum: spans the space between neural arches, yellowish color

•Interspinous ligament: between SP

•Supraspinous ligament: spans between post end SP

•Ligamentum nuchae (nuchal ligament): nuchal line cranium → SP cervical vertebra, sagittal articulations, origin trapezius

•Intertransverse ligaments

movements of vertebral column

range of motion in vertebral joints

-atlanto-occipital: not lot rotation

-altanto-axial: most rotation

-other 3: rotation w/ horizantal plane; lumbar not lot bc peri-sagittal orientation

normal CURVATURES OF THE VERTEBRAL COLUMN

-fetus: not lot curves

-4 years: L and S cruves when start to wal

-Lumbar mordosis

abnormal curvatures of the vertebral column

-Kyphosis: excessive convexity of thoracic region

-Scoliosis: abnormal lateral curvature

*often accompany each other

-(Hyper)lordosis AKA “pelvic tilt”: increased lordotic curve, if pregnant or obese

meninges of spinal cord

+epidural space and subarahnoid space w/ CSF

Spinal cord changes diameter

-Which spinal cord levels contribute to the cervical enlargement of the spinal cord?

-Which spinal cord levels contribute to the lumbar enlargement of the spinal cord?

-C5-T1

-T11-S2

end of the spinal cord

*Cauda Equina=”horses tial”

*Filum terminale: made from pia mater, anchors SC in spinal canal