Vertebrae

Mamillary Process

A smooth rounded projection on the back of each superior articular process

Demifacets

These are formed when the head of a rib articulates with two adjacent vertebral bodies.

What are the three types of Vertebrae?

-Cervical -Thoracic -Lumbar "Cereal at 7, Tea at 12, Lunch at 5"

Siding the Lumbar Vertebrae

-The long axis of each transverse process passes from the vertebral body and lamina superolaterally. -The superior articular facets are concave and face posteromedially, whereas the inferior facets are convex and face anterolaterally. -Note the large gap, the inferior intervertebral notch, between the inferior articular facets and the posterior surface of the vertebral body in lateral aspect. The arch originates from the superior half of the vertebral body.

Siding the Cervical Vertebrae

-The long axis of the spinous process is directed posteroinferiorly. -The superior articular facet face posterosuperiorly, and the inferior one faces the opposite direction. -The uncinate processes are superior and lateral.

Siding the Thoracic Vertebrae

-The long axis of the spinous process is posterior and is angled sharply inferiorly, particularly in the mid-thoracic region. - The superior articular facet faces posteriorly, and the inferior one faces anteriorly. -The costal articulation on the transverse processes faces anterolaterally. -In lateral aspect the inferior articular facets are separated from the rear half of the vertebral body by a considerable gap, the inferior intervertebral notch. -The inferior dimensions of the body are greater than its superior dimensions.

Intervertebral Foraman

Also called a neural foramen, it is a foramen between two spinal vertebrae. Cervical, thoracic, and lumbar vertebrae all have this, though at least two must be flush together to see this.

Vertebral Body

Also called the Centrum, this is the spool-shaped structure that is the main weight-bearing portion of the vertebrae. The body is very thin-walled, composed mostly of lightweight, fragile, spongy bone, and it is therefore very susceptible to postmortem damage. It is also a center for blood production. The large foramen at the midline on its posterior surface is for the exit of the basivertebral vein.

Cervical Vertebrae

Cervical vertebrae that share the characteristic cervical pattern are C-3 through C-6. There are normally 7 vertebrae in this section.

Lumbar Vertebrae

It's easier to identify individual positions of isolated lumbar vertebrae. Like the thoracic and cervical vertebrae, the Lumbars increase progressively in size from superior to inferior (L-1 to L-5). Lumbars are the largest of all the unfused vertebrae. There are normally 5 vertebrae in this section.

Uncinate Process

On the lateral margins of the cervical bodies create bodies which have interlocking, saddle shaped superior and inferior surfaces.

Axis: C2 -Odontoid or Dens

The axis (C-2) lacks a typical vertebral body but has a projecting process, called the dens, or odontoid process, that forms a pivot for the atlas. Thus, when the head is nodded up and down, movement is mostly at the joint between the occipital condyle and C-1. When the head turns from side to side, the atlas rotates about the dens of the axis.

The Cervical Vertebral Body

The bodies of cervical vertebrae are smaller and thinner than those of thoracic or lumbar vertebrae.

The Lumbar Vertebral Body

The bodies of lumbar vertebrae are larger than those of cervical or thoracic vertebrae. Lumbar bodies lack costal pits and transverse foramina. The superior outlines of lumbar bodies are ovoid, although L-1 and L-2 may be somewhat kidney-shaped.

The Thoracic Vertebral Body

The bodies of thoracic vertebrae are intermediate in size between cervical and lumbar vertebrae. Upper thoracic bodies are roughly triangular in superior outline, whereas lower thoracic vertebral bodies are more circular.

Superior and Inferior Cervical Articular Facets

The cervical vertebrae are cup-shaped or planar. The superior and inferior facets are parallel, both pass from anterosuperior to posteroinferior. The inferior facet is situated more posterior to the vertebral body than the superior facet.

Superior and Inferior Lumbar Articular Facets

The facets are not parallel in lumbar vertebrae; instead the superior articular facets are concave, or cupped, and face posteromedially. The inferior articular facets are convex and face anterolaterally.

Superior Articular Facets

The facets face posterosuperiorly in most cervical vertebrae, posteriorly in the thoracic vertebrae, and posteromedially in the lumbar vertebrae.

Vertebral Foramen

The hole in every vertebrae which the spinal cord passes through. Each vertebrae forms a segment of vertebral canal passing down through the vertebral column.

Transverse Process of the Thoracic Vertebrae

The superior articular surfaces are directed upward and backward; the spinous process is thick, long, and almost horizontal. The transverse processes are long, and the upper vertebral notches are deeper than those of the other thoracic vertebrae

Transverse Process of the Lumbar Vertebrae

These are relatively smaller and thinner than thoracic transverse processes and they lack any articular surfaces. They are rudimentary or absent on L-1 and increase in size and projection inferiorly.

Inferior Articular Facets

These facets face in the opposite directions of the superior facets for each vertebral class.

Superior and Inferior Thoracic Articular Facets

These facets, T-12, are very flat and planar. Except for T-1 and T-12, the articular facets are set vertically, facing directly anteriorly, the inferior facet or posteriorly, the superior facet.

The Cervical Vertebral Foramina

These formina are roughly triangular, large and wide relative to the size of the vertebral body.

The Thoracic Vertebral Foramina

These formina are round or diamond-shaped, and are subequal to (T-1), or substantially smaller than (T-2 to T-10), the size of the vertebral body.

The Lumbar Vertebral Foramina

These formina are triangular in outline, and are very small relative to the size of the vertebral bodies.

Transverse Process of the Cervical Vertebrae

These processes are very small and gracile, and each is pierced by a transverse foramen. These foramina house the vertebral arteries, which pass upward to the posterior part of the brain.The lateral portion of the cervical transverse process is complex, consisting of: -A posterior tubercle of the transverse process, the small bump which is the cervical homolog of the tubercle of a rib. -An anterior tubercle of the transverse process, another small bump which is the cervical homolog of a rib head. -The intertubercular lamina, a downward directed arch between the two tubercles which is the cervical homolog of a rib neck.

Spinous Process of the Lumbar Vertebrae

These projects are hatchet-shaped, large, blunt, and more horizontally oriented than other vertebral spinous processes, they are orthogonal to the coronal plane.

Spinous Process of the Thoracic Vertebrae

These projects are longer and more slender than those of cervical or lumbar vertebrae, and each terminates in a distinct tubercle. From a lateral perspective, the spinous processes of the uppermost and lowermost thoracic vertebrae are closer to horizontal than the spinous processes of the middle thoracic vertebrae, which are much more inferiorly inclined

Vertebral Arch

This encloses the spinal cord posterior to the vertebral body. The arch is everything that's not the body. (So for the picture, it's everything not blue)

Lamina

This is posterior to each pedicle, in which the plate-like part of the arch that attaches the pedicle to the spinous process.

Pedicle

This is the short segment of the arch close to the vertebral body, attached more superiorly to the body than inferiorly.

Atlas: C1

This lies between the cranium and the axis. Superior articular facets of the atlas are concave and elongate and receive the condyles of the occipital bone. The atlas vertebra has no vertebral body, lacks a spinous process, and has no articular disks superior or inferior to it. On the posterior surface of the anterior bony rim of this vertebra, the anterior edge of the vertebral foramen, there is an oval articulation for the dens of the axis.

Transverse Process

This process is found on each side of each vertebra. Like spinous processes, the transverse processes act as levers for the muscles attached to them. Movements of the axial skeleton are made possible by the muscles acting on these levers. Movement is restricted by the ligaments that hold the individual vertebrae together. The transverse processes of thoracic vertebrae articulate with the ribs.

Spinous Process of the Cervical Vertebrae

This project fairly horizontally behind the vertebral body, mostly posteriorly, partly inferiorly. They are usually bifurcated from C-1 to C-5, and often asymmetrical at their posterior tips, shorter than thoracic spinous processes, and not as massive as lumbar spinous processes.

Spinous Process

This projects posteriorly on the midline and serves to anchor the interspinous and supraspinous ligaments and several muscles. These ligaments limit flexion of the vertebral column. Because the spinous processes act as levers for muscular action, the length, size, and slope of individual spines depend on the functional role which various back muscles play.

Thoracic Vertebrae

Thoracic vertebrae that share the characteristic thoracic pattern are T-2 through T-6. Each thoracic vertebra articulates with a pair of ribs. There are normally 12 vertebrae in this section.