Information

Vertebrae



Cervical Vertebrae: Mobility and Head Movement

Introduction

The spine is part of the axial skeleton, and is made up of 33 bones: the vertebrae.

It can be said that there are five main regions of the spine: cervical, thoracic, lumbar, sacral and coccygeal.

What are

Vertebrae are bony structures, and they have a common structural plane, with very few variations.

As mentioned earlier, they make up the spine, and they are mobile enough to allow limited movement.

Differentiations occur by the different locations of the vertebrae and functions to be performed, and for this reason the bodies and processes are different.

Anatomical features

As there are 5 types of vertebrae, it is necessary to know the processes and structures present, in general:

- Body: can be oval or spherical, and its main function is the load and pressure support.

- Vertebral discs: structures that allow the articulation between the bodies of two vertebrae.

- Forame: This is the “canal”, which is filled by the medulla.

- Transverse process: joins the pedicle with the blade.

- Pedicles: They are located laterally and posteriorly, and connect the transverse process to the body of the vertebra.

- Spinous process: It is located medial and posterior, and its function is the fixation of muscles and ligaments.

- Articular processes: Present in both the lower and upper parts, they also have the function of articulating one vertebra to another.

Differentiations

As you already know, the column is divided into 5 parts, and each one has its own characteristics.

1. Cervical

In number seven, they are the smallest vertebrae, and the most mobile, due to the need for head movement.

They are characterized by the large foramen ovale, presence of transverse foramen and spina bifida process.

Vertebrae C1 and C2 receive special nomenclatures: atlas and axis, respectively.

2. Thoracic

In number 12, they have as differential the articulation with the ribs, through the fovea (except T XI and T XII).

They have a non-bifid spinous process and a medium-sized, “heart-shaped” vertebral body.

3. Low back

The lumbar portion contains 5 vertebrae, with small vertebral foramen and characteristically short spinous process with posterior projection.

They are expected to carry a large weight, and for this reason they have larger and more resilient vertebral bodies.

4. Sacrum

Although it is composed of 5 vertebrae, they are fused and have their own characteristics, different from the above.

5. Coccyx

It is also composed of fused vertebrae, which can range from three to five. Your projections and joints with the sacrum may vary with gender and age.

Main Functions:

When it comes to vertebrae, some functions can be assigned:

- Provide a passageway for the spinal cord as well as ensure its protection.

- Enable head mobility.

- Ensure the passage of nerves.

- Make weight support.

- Enable the maintenance of the upright posture.

Curiosities

- Although there are usually curvatures in the spine, their accentuation may result in postural deviations such as hyperlordosis and hyperkyphosis.

- Abnormal marrow development may also result in vertebral and spinal abnormalities. Spina bifida is called this congenital alteration.

Last reviewed: 12/05/2018

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By Elaine Barbosa de Souza
Undergraduate student in Biological Sciences, Methodist University of São Paulo.