Vertebral column: Bones and Joints

33

How many vertebrae in early life?

- Encloses and protects the spinal cord

- It acts as a support for the trunk.

- It supports skull superiorly.

- Provides for attachment for the deep

muscles of the back and ribs laterally

Functions of the vertebral column

Intervertebral joints or discs

between adjacent vertebrae

Interarticular joints

between articular processes

Atlantooccipital joints

between occipital bone and atlas

Atlantoaxial joints

- The articulations between the atlas (C1) and the axis (C2)

- There are three of these joints

Lumbosacral joints

5th lumbar vertebra and sacrum

sacrococcygeal joint

Joint between sacrum and coccyx.

Costovertebral joints

Joints between ribs and vertebrae.

costotransverse joint

Tubercle of a rib and transverse process of vertebra

Zygapophyseal joints

Between articular processes of the vertebrae

Cervical, thoracic, lumbar

True or movable vertebrae

Sacrum and coccyx

False or fixed vertebrae

Lordotic Type

Cervical curvature

kyphotic type

Thoracic curvature

Lordotic Type

Lumbar curvature

Kyphotic type

Pelvic curvature

2 transverse

2 superior articular

2 inferior articular

1 spinous process

Seven processes of the vertebra

Body of the vertebra

the solid anterior part shaped like a cylinder, with the posterior surface flattened

Arch of the vertebra

Curved posterior part enclosing an opening

Pedicle

Two short rounded processes that extend posteriorly, one from each lateral margin of the dorsal surface of a vertebral body

Laminae

Two flattened plates of bone, one passing towards the midline from each pedicle

Vertebral foramen

An opening formed by the vertebral arch with its pedicles and laminae, and the posterior surface of the vertebral body

Vertebral canal

Is a tubular passage extending from the foramen magnum of the skull to the lower sacrum

Vertebral notch

Is formed by either the upper or lower curved surface of a pedicle

Intervertebral foramen

Is an opening on each side of the arch

Cervical

- forked spinous processes

- foramina transversia

Thoracic

Costal pits or facet (fovea costalis)

Lumbar

- large size

- no pits

- no foramina transversaria

Sacrum

Five fused bodies

Coccyx

- 4 or 3 or 5 incomplete

- 2 cornua

Intervertebral joints

Flat articular surfaces of bodies of

the adjacent vertebrae from the

second cervical vertebra to and

including the lumbosacral joint

between the 5th lumbar body and

the sacrum.

Intervertebral disc

Flat circular plate lying between the articular cartilages covering each bone

annulus fibrosus

An outer pad of fibrous tissue and fibrocartilage

Nucleus pulposus

The pulpy center of a disc in the center of an annulus fibrosus and surrounded by it

anterior longitudinal ligament

An ... of fibrous tissue extending lengthwise along the anterior surfaces of vertebrae

Posterior longitudinal ligament

A ... passes lengthwise between adjacent vertebrae along their posterior surfaces

Ligamenta flava

Pass lengthwise between the laminae of adjacent vertebrae

Interspinsl ligaments

Ligament: connect adjacent spinous processes

Supraspinous ligament

Ligament: connects the tips of the spinous processes

Gliding joint

What kind of joint? Interarticular joints (Zygapophyseal joint)

Condylar joints

What kind of joint? Atlantooccipital joints

Pivot joint

What kind of joint? Median atlantoaxial joint

Gliding joint

What kind of joint? Lateral atlantoaxial joint

Accessory Cervical Joints

Between the lateral margins of the articular surfaces of lower cervical vertebrae, on each side

Cartilaginous joint

What kind of joint? Lumbosacral joint

Atlantooccipital joint

- occipital condyle of the occipital bone

- superior articular surfaces known as the lateral mass of the atlas on the same side

Median atlantoaxial joint

Dens of the axis and a ring formed by the anterior arch of atlas

Lateral atlantoaxial joints

Inferior articular surface of the lateral mass of the atlas and the superior articular process of the axis on each side

Lumbosacral joint

Inferior articular surface of the 5th lumbar vertebra and the superior articular surface of the sacrum

Interarticular joints

Inferior articular processes of upper end of sacrum

Gliding joints

What kind of joint? Interarticular joints

Sacrococcygeal joint

Distal end of sacrum forming a joint with the first segment of the coccyx

Cartilaginous joint

What kind of joint? Sacrococcygeal joint

Intercoccygeal joints

- present between the segments of the coccyx

- the discs disappear in later life and the segments unite

Fusion of vertebrae

2 or more vertebrae may be united with no joint between them

Hemivertebra

Right or left half of the vertebra may be absent, or one half of the vertebra may fuse with the vertebra above or below it, leaving the other half as a separate bone

Spina bifida

The right and left lamina may fail to unite with each other at the median line posteriorly

Articular defects

May present between superior and inferior articular processes of a vertebrae at the isthmus where these join

Absence of sacrum

The lower part of the sacrum may fail to develop

Sacralization

The 5th lumbar vertebra may be partly or completely fused with the upper sacrum