Anatomy Day 5 Boney Landmarks and Structure of the Vertebral Column

Vertebrae Column ( Spinal Column )

- 26 bones in total, top 24 are called the vertebrae and bottom are called the sacrum and coccyx - Running through the center of the vertebral column is the spinal canal which contains the spinal cord - The spinal cord consists of spinal nerves which emerge between the vertebrae

Stenosis

- Abnormal narrowing of the spinal canal - Most common in cervical and lumbar regions - Caused by degeneration, less commonly by tumors - Symptoms - pain, numbness, weakness - the shopping cart leaners

C2 - The Axis

- Allows C1 to pivot around this axis due to the odontoid process - The spinous process is quite massive - odontoid process also known as dens

C1 - The Atlas

- Holds up the head, but has no body and no spinous process - The vertebral foramen is huge because it has to provide passage for the spinal cord which, at this level is also huge. - The transverse processes are very prominent and may be palpated just inferior to the mastoid process - The atlas has 2 massive superior articular processes whose bowl-shaped facets accommodate the condyles of the occipital bone. This joint enables the occipital bone to rock back and forth on the atlas, thus allowing us to nod our heads "yes"

The sacrum

- In adults, the sacrum consists of 5 fused bones, which are designated as S1-S5. - Between the fused segments are sacral foramina on the anterior and posterior surfaces of the sacrum. - At birth, the 5 sacral segments are not fused. They remain as 5 separate bones until about the age of 20.

What functions do the disc have?

- It firmly joins the bodies of adjacent vertebrae - Cushion that protects the vertebrae bodies from too much compression

Spondylolisthesis

- Slippage of vertebrae -usually L5-S1 - Pain that worsens with spinal flexion and relieved with spinal extension - Causes: traumatic injury, degeneration, and rarely, pathological (tumor leading to lesions)

Spondylolysis

- Stress fractures" of the spine - Low back pain - Not always a definitive cause. Some people develop it with no history of back injury, others may have it and have no pain.

Anterior longitudinal ligament

- The anterior longitudinal ligament is a broad flat ligament that runs along the anterior surface of the vertebral bodies. - It links the bodies together and fuses with the discs. - Its function is to prevent excessive extension of the vertebral column.

The coccyx

- The coccyx consists of 3-5 fused bones. - It is considered to be the vestige of a tail. In fact, babies are often born with a small tail, which projects down from the tip of the coccyx.

Interspinous ligaments

- The interspinous ligaments are situated between the spinous processes of adjacent vertebrae. Numerous muscles help to hold the vertebrae together.

Discs

- The intervertebral disc is situated between adjacent vertebral bodies. - It consists of an outer ring of fibrocartilage called the annulus fibrosis, and a soft gelatinous interior called the nucleus pulposus.

Nuchal ligament

- The nuchal ligament runs from the EOP (external occipital protuberance) to the spinous process of C7.

Posterior longitudinal ligament

- The posterior longitudinal ligament runs along the back of the vertebral bodies. - It is thinner and more delicate than the anterior longitudinal ligament. - Its function is to prevent excessive flexion.

Supraspinous ligament

- The supraspinous ligament is a thin stringy ligament that joins the tips of the spinous processes.

Lumbar Vertebrae

- Whereas the cervical vertebrae are highly mobile, the lumbar vertebrae are built for strength. - They have large bodies and massive spinous processes that are oriented straight back

What are the ligaments of the spine?

- anterior longitudinal ligament, posterior longitudinal ligament, nuchal ligament, supraspinous ligament, interspinous ligaments,

Thoracic Vertebrae

- have long slender spinous processes, which are oriented sharply downward. - have flattened surfaces on the transverse processes and bodies for attachment of the ribs. (T1-T7) - These surfaces are called facets on the transverse processes and demi-facets on the bodies. - Due to the attachment of the ribs to the thoracic vertebrae, the thoracic section is not as freely moveable as the cervical section.

The Herniated Disc

-The term "slipped disc" is wrong - It is possible to have a bulging disc, wherein the annulus fibrosis is overstretched and the nucleus pulposus balloons out. - Even more serious is a ruptured disc, wherein the annulus fibrosis is torn, and the nucleus pulposus escapes. - A bulging or ruptured disc may be called a HERNIATED disc. A herniated disc can press upon a spinal nerve root or even the spinal cord, causing severe pain. Paresthesia - compressed nerve - Only herniates to the right or left because the ligaments are to tough

How many sections of the vertebral column have? And what are they?

5 Sections - Cervical - (Neck) Top 7 vertebrae (C1-C7) - Thoracic - (Upper Back) 12 Vertebrae (T1-T12) (Ribs) - Lumbar - (Lower Back) 5 Vertebrae (L1-L5) - Sacrum - 5 Fused together bones - Coccyx - 3-5 fused together bones

What is one abnormal curve of the spine

Lordosis - Exaggerated inward curve of the lumbar vertebrae Causes - Anterior pelvic tilt, how it grew Kyphosis - Exaggerated outward curve of the thoracic vertebrae - Osteoporosis Scoliosis - Sideways curve of the thoracic and lumbar

Normal Curves of the Vertebrae

Lordotic - The normal inward curve of the lumbar vertebrae and cervical vertebrae Kyphotic - The normal outward curve of the thoracic vertebrae

What forms the vertebral forearm wall?

Pedicles and Laminae form the walls of the forearm

Other typical vertebrae

The inferior articular processes: two projections on the inferior surface of the vertebra. Each of these also has a flattened surface called a facet. Intervertebral foramen: opening in between each vertebrae where the nerves come out

Other typical vertebrae

The transverse processes are lateral projections on the vertebra. The spinous process is a projection on the posterior part of the vertebra. We can feel this The superior articular processes are two projections on the superior surface of the vertebra. Each one has a flattened surface called a facet.

The Typical vertebrae has what?

Vertebral body - is the large rounded portion that forms the anterior part of the vertebra. Vertebral forearm - is the large hole posterior to the body. When all the vertebrae are in their proper position, their vertebral foramina form a continuous tube- the spinal canal.

Cervical Vertebrae (Neck)

have small bodies and large vertebral foramina. The transverse processes of each vertebra have a transverse foramen. The transverse foramina provide passage for the vertebral artery, which supplies the brain. The vertebrae are difference in C1 AND C2