Vertebral Column Flashcards
Central bony pillar of the body; 72 to 75 cm in length (1/4 is formed by the IV discs)
Vertebral column
Functions of vertebral column
Support
Protection
Locomotion
Regions of vertebral column
Cervical Thoracic Lumbar Sacral Coccygeal
No. of vertebrae in: cervical
7
No. of vertebrae in: thoracic
12
No. of vertebrae in: lumbar
5
No. of vertebrae in: sacral
5 (fused)
No. of vertebrae in: coccygeal
4 (lower three fused)
Parts of vertebra
Body
Vertebral arch
Seven processes
Anterior part of the vertebra
Body
Posterior to the vertebral body and enclosed the vertebral foramen
Vertebral arch
Gives rise to 7 processes
Vertebral arch
2 parts of vertebral arch
Pedicles and laminae
attached to the vertebral body forming the sides of the arch
Pedicles
- flattened
- attached to the pedicle
- completing the arch posteriorly
Laminae
Where the spinal cord and its coverings run though
Vertebral foramen
Contains the spinal cord and the roots of the spinal nerves, along with the meninges, fat, and vessels that surround and serve them
Vertebral canal
Formed by the succession of vertebral foramina in the articulated vertebral column
Vertebral canal
Notch on the upper and lower border of the pedicles that are formed by the projection of the body (anteriorly) and the articulating processes (posteriorly)
Vertebral notch
The superior notch of one vertebra + inferior notch of an adjacent vertebra = ?
intervertebral foramina
Serve to transmit spinal nerves and blood vessels and Where anterior and posterior nerve roots of a spinal nerve unite to form the segmental spinal nerves
intervertebral foramina
Types of processes
Spinous process
Transverse process
Articular process
Process:
- Median
- Projects posteriorly from the vertebral arch at the junction of the laminae
Spinous process
Number of spinous process
1
Process: Directed laterally from the junction of the pedicles and laminae
Transverse process
Number of transverse process
2
T or F: Both spinous and transverse processes serve as levers and attachments of muscles and ligaments, facilitating the muscles that fix or change the position of the vertebrae
T
Process:
- Vertically arranged
- Consist of 2 superior and 2 inferior processes
- Arise from the junction of the laminae and the pedicles
Articular process
Number of articular process
4
Articular surfaces are covered with _______
hyaline cartilage
Assist in keeping adjacent vertebrae aligned, preventing one vertebra from slipping anteriorly
Articular processes
Typical cervical vertebrae
C3-C6
Vertebrae from the skeleton of the neck
Cervical vertebrae
T or F: the vertebral artery passes through the transverse processes of C1 to C7.
F, C1 to C6, not C7
Atypical cervical vertebra
C1, C2, C7
– atlas
- Body: no body
- Vertebral arch: has an anterior and posterior arch – ring-shaped bone
C1
– axis
- Has a peg-like odontoid process (dens) that projects from the superior surface of the body
- The dens represents the body of the atlas that has fused with the body of the axis
C2
Called the vertebra prominens because its prominent – palpable at the back of the neck
C7
For articulation with the ribs
Found in transverse process – for articulation with tubercle of rib
Found in vertebral body – on the sides, for articulation with head of rib
costal facets
- In the upper back and provide attachment for the ribs
- Body: medium-sized, and heart-shaped
Thoracic vertebra
In the lower back, between the thorax and the sacrum
- Body: massive (because of the weight they support), and kidney-shaped
Lumbar vertebra
Largest lumbar vertebra
L5
anterior projection of the upper margin of S1; posterior margin of the pelvic inlet; signals the beginning of the rectum, also used in measuring the size of the pelvis in females
Sacral promontory
formed by the vertebral foramina, extension of the vertebral canal
- contains the anterior and posterior roots of the sacral and coccygeal spinal nerves, filum terminale, and fibrofatty material
- also contains the lower part of the subarachnoid space down as far as the lower border of S2
Sacral canal
Consists of five rudimentary vertebrae fused together to form a wedge-shaped bone; Concave anteriorly
Sacrum
The sacral vertebra contains how many foramina on each side?
4
Longitudinal ridges of the sacral vertebra
Median sacral crest
Intermediate sacral crest
Lateral sacral crest
the laminae of S5 (and sometimes S4) fail to meet in the midline forming a space/ hiatus
Sacral hiatus
Consists of four vertebrae fused together to form a single, small, triangular bone
Coccyx
T or F: Only thoracic and sacral curvature remain kyphotic throughout life – these are the primary curves
T
Curvature that develop during fetal development
Primary curvature
The angles or the curvature form during fetal period but become prominent after infancy
Secondary curvature
2 primary ligaments of the vertebral column
Anterior longitudinal ligament
Posterior longitudinal ligament
Fibrous band that covers and connects the anterolateral aspects of the vertebral bodies and iv discs
Anterior longitudinal ligament
Prevents hyperextension of the vertebral column; Found outside of the vertebral canal
Anterior longitudinal ligament
Weak and narrow, attached to the posterior border of the discs; Runs within the vertebral canal along the posterior aspect of the vertebral bodies
Posterior longitudinal ligament
Upward continuation of PLL at level of atlantoaxial joint
Tectorial membrane
Prevents hyperflexion of vertebral column; Helps prevent or redirect posterior herniation of nucleus pulposus
Posterior longitudinal ligament
Accessory ligaments
Ligamentum flavum Interspinous ligaments Supraspinous ligament Ligamemtum nuchae Intratransverse ligaments
in the cervical region, the supraspinous and interspinous ligaments are greatly thickened to form the strong __________
ligamemtum nuchae
Ligament: Elastic tissue that joins together laminae of adjacent vertebral arches
Ligamemtum flavum
Ligament: Connects adjoining spinous processes (attaching from the root to the apex of each process)
Interspinous ligament
Ligament: Cord-like band that connects the tips of the spinous processeses from C7 to the sacrum
Supraspinous ligament
Ligament: Strong and broad; thickened fibroelastic tissue that extends from the spine of C7 to the external occipital protuberance of the skull, with its anterior border being strongly attached to the cervical spines in between
Ligament nuchae
Ligament: Connects one transverse process to another
Intratransverse ligament
Main structures that bind together the vertebral bodies
Intervertebral disc
Responsible for ¼ (20-25%) the length of the vertebral column
Intervertebral disc
Number of invertebral discs
23
Serve as shock absorbers when the load on the vertebral column is suddenly increased (e.g. when jumping from a height); Elasticity allows the rigid vertebrae to move one on the other (resilience is lost gradually with age)
Intervertebral discs
Parts of intervertebral disc
Annulus fibrosus
Nucleus pulposus
Peripheral part of the intervertebral disc and is composed of fibrocartilage.
Annulus fibrosus
Central part of the invertebral disc and contains an ovoid mass of gelatinous material containing a large amount of water, small amount of collagen fibers, and a few cartilage cells in children and adolescents
Nucleus pulposus
Joints of the vertebral column
Atlanto-occipital joint
Atlanto-axial joint
Type of joint: atlanto-occipital joint
Synovial: condyloid
Type of joint: atlanto-axial
Synovial: Pivot
atlanto-occipital joint movements
Flexion, extensions, lateral flexion, NO ROTATION possible
atlanto-occipital joint articulations
occipital condyles of the skull (superior) + superior surfaces of the lateral masses of the atlas (inferior)
Ligaments of the atlanto-occipital joint
anterior and posterior atlanto-occipital membrane
Connects anterior arch of atlas to the anterior margin of the foramen magnum
Anterior atlanto-occipital membrane
Connects posterior arch of atlas to the posterior margin of the foramen magnum
posterior atlanto-occipital membrane
Atlantoaxial joint articulation
odontoid process + anterior arch of the atlas (1 joint)
lateral masses of the bones (2 joints)
Atlantoaxial joint movement
Extensive rotation of atlas
Ligaments of atlantoaxial joint
Apical
Alar
Cruciate
Membrana tectoria
Connects the apex of the odontoid process to the anterior margin of the foramen magnum
Apical ligament
Connects the odontoid process to the medial sides of the occipital condyles
Alar ligament
attached one on each side of the inner aspect of the lateral mass of the atlas
- binds to the odontoid process to the anterior arch of the atlas
Transverse ligament
Covers the posterior surface of the odontoid process and the apical, alar, and crucial ligaments
Membrana tectoria
Procedure done at the level of L4 to:
- Withdraw a sample of cerebrospinal fluid for examination
- For clinical diagnosis
- Introduce drugs
- Remove excess CSF
Lumbar tap
Structures traversed by spinal needle
- Skin
- Superficial fascia
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Areolar tissue (containing internal vertebral venous plexus in epidural space)
- Dura mater
- Arachnoid mater
- Subarachnoid space
Why is the lumbar tap at the level of L4?
at lower lumbar part of vertebral canal the subarachnoid space only contains the cauda equine a needle introduced at this level usually just pushes the nerve roots to the side without causing damage
Clinical condition:
- Spinous process, laminae, and inferior articular process separate from the body pedicles and the superior articular process
- Common in adolescent athletes
Spondylosis
Clinical condition:
- Body of a lower lumbar vertebra (usually L5), moves forward on the body of the vertebra below and carries with it the whole of the upper portion of the vertebral column
Spondylolisthesis
Clinical condition:
Pedicles are abnormally formed and accessory centers of ossification are present and fail to unite
Congenital spondylolisthesis
Clinical condition:
- Common in elderly
- Involves degeneration of the IV discs in the lumbar region and osteoarthritis of the intervertebral joints
Degenerative spondylolisthesis
Protusion of nucleus pulposus; Disc most commonly affected are those in areas where a mobile part of the column joins a relatively mobile part
HERNIATION OF INTERVERTEBRAL DISC