Vertebrae - The back Flashcards
Cervical vertebrae
CI-CVII (1-7)
Base of skull
Body
- Square shaped from above
- Concave superior
- Convex inferior
- Short in height
Transverse process
- Through and perforated by foramen transversarium
Spinous process
- Are bifid (there are two, looks like a dolphin tail)
Vertebral foramen is triangular
Thoracic Vertebrae
TI-TXII(1-12)
Anterior chest area
Articulated with ribs
- Usually contain two partial facets (superior and inferior) which allow for articulation with the head of its own rib. (superior is larger)
- Transverse processes also have facets (transverse costal facet)
- For the articulation with tubercle of the rib
Is heart shaped from above
Lumbar Vertebrae
LI-LV (1-5)
Anterior to the ribs posterior to the sacrum
Large and have no facets for articulation with ribs
Transverse processes are thin and long except for the LV which is massive and cone shaped
- Cone shaped for iliolumbar ligament attachments to connect them to pelvic bones
Cylindrical shaped with triangular larger foramen than in the thoracic vertebrae
Sacrum Vertebrae
5 fused vertebrae (I-V)
Anterior to lumbar superior to Coccyx
Triangular when apex pointed inferiorly and it is curved concave anterior surface
Two large L-shaped facets one on each lateral surface
- Articulation with pelvic bones
- 4 pairs of anterior sacral foramina for passage of the ramis S1-S4
Coccyx
3-4 fused coccygeal vertebrae (I-IV)
Most anterior vertebrae
Small and triangular
No vertebral arches or canal.
General structure of a vertebrae
Vertebral body (weight bearing) linked by discs and ligaments
Vertebral arch
Two pericles = attach the arch to the body
Two laminae = flat bone that forms the roof of the arch
Vertebral foraminal = aka the CANAL that is continuous through the foramen magnum of the skull with cranial cavity of the head
Spinous process = inferior and posterior to laminae
Transverse process = posterior laterally to laminae
Superior and inferior vertebral notches = which form the intervertebral foramina.
Vertebra CI (Atlas)
Ring shaped from above
Lacks a vertebral body
- Fuses with CII during development to become the CII dens (no intervertebral disk)
Is composed of two lateral masses, that are interconnected by an anterior and posterior arch
- The masses go above a skull condyle and below the superior articular process of CII
- Superior articular surfaces are BEAN shaped
- Inferior are circular and flat
Atlanto-occipital joint
Allows nodding of the head on the vertebral column
Dens
On the anterior arch there is a facet for the dens that is held by a strong transverse ligament of the atlas
It acts as a pivot that allows rotation from side to side.
Large protruding transverse processes (more than cervical) for muscle action
The muscles at the atlanto-axial joints.
Vertebra CII (Axis)
Large dens extend from the body superiorly.
Anterior surface has an oval facet for articulation
Attachment sites for strong ligaments on superolateral surfaces of the dens
Alar ligaments. (Check excessive rotation of the head and atlas relative to the atlas)
Symphyses (Intervertebral Discs) - Cartilaginous Joints
Located between adjacent vertebral bodies.
Each disc has:
Anulus fibrosus (outer ring of fibrocartilage) → Limits rotation.
Nucleus pulposus (gel-like core) → Absorbs compression forces.
Degeneration of the anulus fibrosus can lead to herniation of the nucleus pulposus, potentially impinging spinal nerves.
Zygapophysial Joints (Facet Joints) - Synovial Joints
Between superior and inferior articular processes of adjacent vertebrae.
Regional differences:
Cervical: Sloped joints → Allow flexion/extension.
Thoracic: Vertical joints → Restrict flexion/extension, allow rotation.
Lumbar: Curved/interlocking joints → Limit movement but allow flexion/extension.
Uncovertebral Joints (Cervical Spine)
Found between uncinate processes of cervical vertebrae and vertebral bodies above them.
Small synovial joints that may develop with age.
Ligaments Supporting Vertebral Articulations
Anterior & Posterior Longitudinal Ligaments: Run along vertebral bodies (anteriorly and posteriorly).
Ligamenta Flava: Elastic tissue between laminae, resists flexion.
Supraspinous Ligament: Connects spinous processes, becomes ligamentum nuchae in the cervical region.
Interspinous Ligaments: Between adjacent spinous processes, blending with surrounding ligaments.
Spinal cord in the vertebral column
The spinal cord runs through the vertebral canal, which is formed by the vertebral foramina of stacked vertebrae.
The posterior longitudinal ligament lines the anterior surface of this canal.
The ligamenta flava and other ligaments help stabilize the vertebral column and protect the spinal cord.
Spinal nerves and vertebral foramina
Spinal nerves exit through the intervertebral foramina, which are openings between adjacent vertebrae.
Herniation of an intervertebral disc (especially posterolateral herniation) can compress spinal nerve roots in these foramina.
Regional differences in the spinal cord and vertebral column
The spinal cord is shorter than the vertebral column in adults.
Cervical and lumbar enlargements exist where nerves for the limbs emerge.
The cauda equina is a bundle of nerve roots extending from the lower spinal cord to exit at lower vertebral levels.
