Lecture 5 - The Vertebral Column

Question 1

What are the 3 primary functions of the vertebral column?

Answer 1

• support
• protection (of spinal cord & nerves)
• movement

Question 2

How many vertebrae’s are there in the vertebral body?

Answer 2

• 33

Question 3

What are the 33 vertebrae that are in the vertebral body?

Answer 3

• cervical (7)
• thoracic (12)
• lumbar (5)
• sacrum (5, fused)
• coccyx (4, fused)

Question 4

What is the vertebral arch?

Answer 4

• Forms the posterior portion of each vertebra
• consists of 4 parts:
• pedicle (2)
• lamina (2)

Question 5

What is the pedicle?

Answer 5

• Each pedicle forms one of the lateral sides of the vertebral arch
• Anchored to the posterior side of the vertebral body

Question 6

What is the lamina?

Answer 6

• Forms part of the posterior roof of the vertebral arch

Question 7

How many processes are there in a vertebra ?

Answer 7

• 7

Question 8

What are the 7 processes of a typical vertebra?

Answer 8

• spinous process (1)
• transverse process (2)
• articular process (4)

Question 9

What is the spinous process?

Answer 9

• Projects posteriorly at then midline of the back
• Serves as an attachment point for muscles

Question 10

What is the transverse process?

Answer 10

• Paired
• Projects laterally & arises from the junction point between the pedicle & lamina
• Serves as an attachment point for muscles

Question 11

What is the articular processes?

Answer 11

• Made up by 2 superior articular process which extends or faces upward & 2 inferior articular process which faces or projects downward on each side of a vertebrae
• The paired superior articular processes of one vertebra join with the corresponding paired inferior articular processes from the next higher vertebra

Question 12

What is the cervical vertebrae?

Answer 12

• The vertebral foramen are relatively large & triangular
• Cervical vertebrae have a small body, carrying the least amount of weight
• The spinous process are often bifid (split) from C3-C6
• The articular processes are oriented almost horizontally

Question 13

What foramen is present only in the cervical vertebrae & why?

Answer 13

• The transverse foramen is only present in the cervical vertebrae and is an opening that allows the vertebral artery to pass through

Question 14

What is the C1 vertebrae?

Answer 14

• Also known as the atlas because it supports the skull on top of the vertebral column
• Ring shape, consisting of an anterior & posterior arch

Question 15

What is the C2 vertebrae?

Answer 15

• Also known as the axis, because it serves as the axis for rotation when turning the head
• Easily distinguished by the dens (odontoid process)
  - A bony projection that extends upward from the vertebral body
  - Joins the inner aspect of the anterior arch of the atlas, held in place by the transverse ligament

Question 16

What is the C7 vertebrae?

Answer 16

• The most prominent spinous process in 70% of people

Question 17

What is the thoracic vertebrae?

Answer 17

• Larger then the cervical vertebrae
• The spinous process is long with a pronounced downward angle that overlaps the next inferior vertebra (Resembles a giraffe head)
• Have several articulation sites called a facet which is where a rib is attached

Question 18

What is the lumbar vertebrae?

Answer 18

• Carries the greatest amount of body weight
• Characterized by the large size & thickness of the vertebral body
• Resembles a moose head
• Short spinous proces

Question 19

What is the sacrum?

Answer 19

• A triangular shaped bone that is thick & wide across its superior base where it is weight bearing & then tapers down to an inferior non-weight bearing apex

Question 20

What are the features of the sacral crest?

Answer 20

• sacral canal
• sacral foramina
• Base
• Apex
• Median Sacral Crest
• Intermediate Sacral Crest
• Lateral Sacral Crest
• Articular Surface

Question 21

What is the sacral canal?

Answer 21

• A continuation of the spinal canal & runs throughout the greater part of the sacrum
• Lodges the sacral nerves

Question 22

What is the sacral foramina?

Answer 22

• Openings that connect to the sacral canal that allow for the anterior & posterior branches of the sacral spinal nerves to exit the sacrum
• 2 posterior (dorsal) sacral foramen, 2 anterior (ventral) sacral foramen

Question 23

What is the median sacral crest?

Answer 23

• forms the fusion of the first 3 sacral spinous processes
• serves as an attachment point for the supraspinous ligament

Question 24

What is the intermediate sacral crest?

Answer 24

• form by the fusion of the articular processes
• an attachment point for the posterior sacroiliac ligaments

Question 25

What is the lateral sacral crest?

Answer 25

• form by the fusion of the transverse processes
• attachment site for the sacroiliac & sacrotuberous ligaments

Question 26

What is the coccyx?

Answer 26

• Also known as the tailbone, is derived from the fusion of four small coccygeal vertebrae
• Articulates with the inferior tip of the sacrum
• Not weight bearing when standing, may receive some body weight when sitting

Question 27

what is the intervertebral discs?

Answer 27

• fibrocartilaginous pad that provide padding between vertebrae during weight bearing
• Each disc is anchored to the bodies of its adjacent vertebrae
• Thin in the cervical region & thick in the lumbar region
• Are flexible & can change shape to allow for movements of the vertebral column

Question 28

What are the 2 parts of the intervertebral discs?

Answer 28

• annulus fibrosus
• nucleus fibrosus

Question 29

What is annulus fibrosus?

Answer 29

• Tough, fibrous outer layer of the disc
• Forms a circle & is firmly anchored to the outer margins of the adjacent vertebral bodies

Question 30

What is nucleus fibrosus?

Answer 30

• Softer, gel-like material
• Serves to resist compression & is important for weight bearing

Question 31

What is the posterior longitudinal ligament?

Answer 31

• Found anterior to the spinal cord where it is attached to the posterior sides of the vertebral bodies
• Limits Flexion of the vertebral column & reinforces the intervertebral discs

Question 32

What is the anterior longitudinal ligament?

Answer 32

• Runs down the anterior side of the entire vertebral column
• Resists excess backward bending of the vertebral column

Question 33

What is the facet/zygapophysial joint?

Answer 33

• A plane synovial joint
• Between the superior & inferior articular processes of adjacent vertebrae
• Each is surrounded by a thin joint capsule

Question 34

What are the 2 craniovertebral joints?

Answer 34

• atlanto-occipital joint
• atlanto-axial joints

Question 35

What is the atlanto-occipital joint?

Answer 35

• Between C1 & occipital condyles
• Synovial - condyloid
• Allows Flexion-extension of the head (i.e., nod back & fourth)

Question 36

What are the atlanto-axial joints?

Answer 36

• Three separate joints between C1 & C2
• Median joint - synovial pivot
  
  • Articulation of the posterior surface of the anterior arch of the atlas & the anterior surface of the transverse ligament at the back of the odontoid process
  • Allows for rotation & some Flx-ext
• Lateral joints (2) - synovial plane

Question 37

What are the 3 types of spinal curvature?

Answer 37

• kyphosis
• lordosis
• scoliosis

Question 38

What is kyphosis?

Answer 38

• An excessive posterior curvature of the thoracic region (i.e., the spine is convex posteriorly)

Question 39

What is lordosis?

Answer 39

• An excessive anterior curvature of the lumbar region (i.e., the spine is concave posteriorly)

Question 40

What is scoliosis?

Answer 40

• A lateral curvature of the spine often compensated by a curve in the opposite direction

Question 41

What is Cauda Equina?

Answer 41

• The spinal cord does not extend the full length of the vertebral canal but rather ends at L1/L2 (conus terminalis)
• The remaining nerve roots extend down the canal in what looks like the hair of a horse’s tail, called the Cauda Equina