The Neck and Trunk

How many regions of the vertebral column are there? What are they?

5: cervical, thoracic, lumbar, sacral, and coccyx

How many vertebrae are there? How many in each section?

• 32 total

• 7 cervical

• 12 thoracic

• 5 lumbar

• 5 sacral (fused)

• 3 coccyx (fused)

What does lordosis/lordotic mean?

• Greek for bent backward

Excessive anterior concavity in the spine

What sections of the spine are in lordosis?

The cervical and lumbar sections

What does kyphosis/kyphotic mean?

• Greek for humpback

• Means excessive posterior concavity

What sections of the spine are in kyphosis?

The thoracic and sacral regions

What movements is the spine able to achieve?

Triaxial motion: flexion/extension, lateral flexion, and rotation

What plane and axis do flexion, extension, and hyperextension occur in?

The sagittal plane and the frontal axis

What plane and axis does lateral bending occur in?

The frontal plane and the sagittal axis

What plane and axis does rotation (of the neck and trunk) occur in?

The transverse plane and the vertical axis

What is the spine?

The bony structure that houses the spinal cord

What is a facet joint?

A small, smooth, flat bony articulation between the superior articular process and the vertebra below with the inferior articular process of the vertebra above; also called the apophyseal

What is a intervertebral facet joint?

Articulation of the superior facet of a vertebrae below and the inferior facet of a vertebrae above

What is a costovertebral facet joint?

Articulation between the head of each rib with the costal facet of a vertebral body

What is the occipital bone?

• Contains the foramen magnum (the opening of the skull for the spinal cord)

Where does the occiput articulate with the atlas (C1)?

The occipital condyles

What is the mastoid process?

The bony prominence behind the ear where the sternocleidomastoid attaches

What is the transverse foramen?

The opening in the transverse process of the cervical vertebra through which the vertebral artery passes

What are the vertebral disks? What do they do?

• The disks are the structures between adjacent vertebral bodies

• Main functions: absorbing and transmitting shock and maintaining flexibility

• Make up 25% of the length of the vertebral column

What are the two main portions of the vertebral disks?

• Annulus fibosus

• Nucelus Pulposus

What is the annulus fibrosus?

The outer portion of the disk composed of concentric fibrocartilaginous rings

What is the nucleus pulposus?

The pulpy, gelatinous substance with high water content

What is the atlas?

• The 1st cervical vertebra (C1)

• Ring-shaped

• Does not have a body or a spinous process

What is the axis?

• The 2nd cervical vertebra (C2)

• Concave underside, convex side to side

• Has a spinous process (odontoid) called the dens

What is the atlanto-occipital joint?

• The articulation between the head and the atlas (C1)

• Condyles of the occiput articulate with he superior articular processes of the atlas

What are the primary motions that occur at the atlanto-occipital joint?

Capital flexion (tucking chin) and extension (tilting head back)

What is are the ligaments of atlanto-occipital joint?

• Anterior atlanto-occipital membrane

• Tectorial membrane

• Posterior atlanto-occipital ligament

What is the atlantoaxial joint?

The articulation between C1 and C2

What motion(s) occur at the atlantoaxial joint?

Cervical rotation

What is the anterior-occipital membrane?

An extension of the anterior longitudinal ligament

What is the tectorial membrane?

An extension of the posterior longitudinal ligament

What is the posterior atlanto-occipital ligament?

Stabilizes the weight of the head in the neck

What is the dens (odontoid process)?

A large vertical projection located anteriorly on the axis

What is the median atlantoaxial joint?

The dens articulates with the atlas at the facet for the dens on the anterior arch of the atlas

What are the lateral atlantoaxial joints?

Located between the articular process of the two vertebrae

What is the alar ligament?

• Runs from the occipital bone to the axis

• Limits rotation

• Can be damaged during trauma to the cervical spine

What is the transverse ligament?

• Secures the dens against the atlas

• Laxity of this ligament can lead to atlantoaxial instability

What type of patients often have atlantoaxial instability?

Patients with down syndrome

What are the articulations the spine?

• Similar articulation from C2 - S1

• Weight-bearing at: the anterior between vertebral bodies and posterior on the facet joints

• Facet joints are synovial joints

What is the alignment of the facets of the cervical spine?

Articular processes are oriented diagonally (oblique) between sagittal and frontal planes which allows triaxial movement including: lateral bending, rotating, and flexion/extension

What is the alignment of the facets of the thoracic spine?

The articular processes are oriented in the frontal plane which allows for rotation and lateral bending

What is the alignment of the facets of the lumbar spine?

The articular processes are in the sagittal plane which facilitates flexion and extension, slight lateral flexion, and no rotation

Which spinal ligament prevents hyper extension?

The anterior longitudinal ligament

What spinal ligament prevents excessive flexion?

The posterior longitudinal ligament

Where does the supraspinal ligament run?

C7 to the sacrum

Where does the interspinal ligament run?

Runs between spinous processes

What is the nuchal ligament?

The equivalent of the supraspinal and interspinal ligament in the cervical spine

What is the ligamentum flavum?

Connects adjacent laminae anteriorly

What are the functions of the cervical spine?

• Allows a lot of movement

• Allows the nervous system to enter through the vertebral canal

• Allows the vascular system to enter and exit the skull

What is the function of the thoracic spine?

The attachment of ribs, the shape of the vertebrae, and the length of the spinous processes limit the motion of the thoracic spine

What is the most injured region of the body?

The lumbar spine

What sections of the lumbar spine that are most frequently herniated?

L4-L5 and L5-S1

Where is the COG along the lumbar spine located?

Anterior to S2

What do the transversospinalis muscles do?

**just need to know the slide

What direction does flexion increase pressure on the spine?

Pressure increases anteriorly and pushes the nucleus pulposus posteriorly

What direction does extension increase pressure on the spine?

Pressure increases posteriorly and pushes the nucleus anteriorly