The structure and shape of the vertebrae

The spinal column (columna vertebralis) - the real basis of the skeleton, bearing the entire body. The design of the spine allows it, while maintaining flexibility and mobility, to withstand the same load, which can withstand up to 18 times thicker concrete pole.

The spinal column is responsible for maintaining posture, serves as a support for tissues and organs, as well as take part in forming the walls of the chest, pelvis and abdomen. Each of the vertebrae (vertebra), make up the spine, inside has a through hole vertebrate (foramen vertebrale). In the spine vertebral openings are the spinal canal (canalis vertebralis), containing the spinal cord, which is thus protected from external influences.

In the frontal projection of spine clearly highlighted two areas of differing broader vertebrae. In general, weight and size of the vertebrae grow in the direction from top to bottom: it is necessary to compensate for the increasing burden carried by the lower vertebrae.

In addition to thickening of the vertebrae, the necessary degree of strength and elasticity of the spine provides a few twists of his lying in the sagittal plane. Four different directions of bending, alternating the spine, are located in pairs, bending, facing forward (lordosis), corresponds to a bend facing backwards (kyphosis). Thus, the cervical (lordosis cervicalis) and lumbar (lordosis lumbalis) lordosis respond chest (kyphosis thoracalis) and sacral (kyphosis sacralis) kyphosis (Fig. 3). With this design, the spine works like a spring, distributing the load evenly over its entire length.

 In Fig. 3.
The spinal column to the right kind of
1 - cervical lordosis;
2 - thoracic kyphosis;
3 - lumbar lordosis;
4 - sacral kyphosis;
5 - protruding vertebra;
6 - the spinal canal;
7 - spinous processes;
8 - vertebral body;
9 - intervertebral openings;
10 - sacral canal
In Fig. 4.
The spine, front view
1 - cervical vertebrae;
2 - thoracic vertebrae;
3 - lumbar vertebrae;
4 - sacral vertebrae;
5 - Atlanta;
6 - transverse processes;
7 - coccyx

How many vertebrae?
A total of 32-34 spine vertebrae separated by intervertebral disks and their slightly different device.

The structure of a single vertebra is isolated vertebral body (corpus vertebrae) and vertebrae arch (arcus vertebrae), which closes the vertebrate hole (foramen vertebrae). Located on the arc of the vertebral spines of different shape and purpose: paired upper and lower articular processes (processus articularis superior and processus articularis inferior), paired transverse (processus transversus) and one bearded (processus spinosus) process, acting on the vertebral arch backward. The base of the arc is the so-called vertebral notch (incisura vertebralis) - top (incisura vertebralis superior) and bottom (incisura vertebralis inferior). Intervertebral foramen (foramen intervertebrale), formed by two adjacent vertebral notches, open access to the vertebral canal on the left and right.

In accordance with the location and structural features in the spinal column distinguishes five types of vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral and 3-5 coccygeal.

Cervical vertebra (vertebra cervicalis) is different from others in that it has a hole in the transverse processes. Vertebrate hole formed by the arc of the cervical vertebra, a large, almost triangular in shape. The body of cervical vertebra (except I cervical vertebra, which the body does not have) a relatively small, oval and elongated in the transverse direction.

I have cervical vertebra, or atlas (atlas), the body is missing, and his lateral masses (massae laterales) connected by two arches - the anterior (arcus anterior) and rear (arcus posterior). The upper and lower planes of the lateral masses are the joint surfaces (top and bottom), by which I connected to the thoracic vertebrae, respectively, with the skull and cervical vertebra II.

In Fig. 5.
I cervical vertebra atlas
A - top view, B - view from below:
1 - back arc;
2 - vertebrate hole;
3 - transverse process;
4 - hole transverse process;
5 - costal process;
6 - lateral masses;
7 - upper glenoid fossa Atlanta;
8 - cavity of the tooth;
9 - anterior arch;
10 - lower glenoid fossa

In turn, II cervical vertebra, characterized by the presence of a massive body in the process, the so-called tooth (dens axis), which originally was part of the body I cervical vertebra. Tooth II cervical vertebra - the axis around which the head with the atlas, so II cervical vertebra is called the axis (axis).

In Fig. 6.
II cervical vertebra
A - front view;
B - view from the left:
1 - tooth axis vertebra;
2 - the upper articular process;
3 - transverse process;
4 - the lower articular process;
5 - vertebral body;
6 - arc vertebra;
7 - spinous process;
8 - hole transverse process


 


 

In Fig. 7.
VI cervical vertebra from the top view
1 - spinous process;
2 - vertebrate hole;
3 - the lower articular process;
4 - upper articular process;
5 - vertebral body;
6 - the transverse process;
7 - hole transverse process;
8 - edge process

On the transverse processes of cervical vertebrae can be found rudimentary edge processes (processus costalis), which are particularly well developed in the VI cervical vertebra. VI cervical vertebra is also acting (vertebra prominens), since its spinous process much longer than that of the adjacent vertebrae.

Thoracic vertebra (vertebra thoracica) features a large, in comparison with cervical, body, and nearly round-hole vertebrates. Thoracic vertebrae have a transverse process at its costal pit (fovea costalis processus transversus), which serves to connect the ribs with tubercles. On the lateral surfaces of the body is also thoracic upper (fovea costalis superior) and lower (fovea costalis inferior) edge pits, which include the head of the rib.

In Fig. 8.
VIII thoracic vertebra  
A - right side view;
B - top view:
1 - the upper articular process;
2 - the upper vertebral notch;
3 - upper rib-pit;
4 - transverse process;
5 - rib-hole transverse process;
6 - vertebral body;
7 - spinous process;
8 - lower articular process;
9 - the lower vertebral notch;
10 - lower rib-pit;
11 - arc vertebra;
12 - hole vertebrate

 
In Fig. 9.
III lumbar vertebrae top view
1 - spinous process;
2 - the upper articular process;
3 - the lower articular process;
4 - transverse process;
5 - vertebrate hole;
6 - vertebral body

Lumbar spine (vertebra lumbalis) differ horizontally directed spinous processes with small gaps between them, as well as a massive bean-shaped body. Compared with the vertebrae of the cervical and thoracic lumbar vertebra has a relatively small vertebrate hole oval.

Sacral vertebrae are separated before the age of 18-25 years, after which they are fused together to form a single bone - the sacrum (os sacrum). The sacrum is triangular in shape, apex downwards, it is isolated base (basis ossis sacri), top (apex ossis sacri) and the lateral part (pars lateralis), and anterior pelvic ( facies pelvica) and rear (facies dorsalis) surface. Inside the sacrum sacral canal passes (canalis sacralis). The reason the sacrum articulates with the V lumbar vertebra and the top - with the coccyx.

In Fig. 10.
Sacrum
A - front view;
B - back view:
1 - base of sacrum;
2 - the superior articular process I sacral vertebra;
3 - anterior sacral foramen;
4 - cross the line;
5 - the top of the sacrum;
6 - sacral canal;
7 - sacral posterior aperture;
8 - median sacral crest;
9 - the right ear-shaped surface;
10 - intermediate sacral crest;
11 - lateral sacral crest;
12 - sacral gap;
13 - sacral horns

 

The lateral part of the sacrum are formed by the transverse processes and fused ribs rudimentary sacral vertebrae. The upper sections of the lateral surface of the lateral parts of the ear-shaped articular surface are (facies auricularis), whereby the sacrum articulates with the pelvic bones.

In Fig. 11.
Coccyx
A - front view;
B - back view:
1 - coccygeal horn;
2 - outgrowths of the body I coccygeal vertebra;
3 - coccygeal vertebrae

The front surface of the pelvic sacrum is concave, with visible marks of fusion of vertebrae (transverse lines are of the form) forms the back wall of the pelvic cavity.

Four lines that mark the place seam sacral vertebrae, ends on both sides of the anterior sacral foramen (foramina sacralia anteriora).

The back (dorsal) surface of the sacrum, also has four pairs of posterior sacral foramen (foramina sacralia dorsalia), rough and convex, with passing the center of the vertical comb. This medial sacral crest (crista sacralis mediana) is the trace of seam spinous processes of sacral vertebrae. Left and right of the intermediate sacral crests are (crista sacralis intermedia)), formed by fusion of the articular processes of the sacral vertebrae. Fused sacral vertebrae transverse processes form the lateral sacral crest pair (crista sacralis lateralis).

Intermediate sacral crest pair ends at the top of the usual superior articular process I sacral vertebra, and below - modified the lower articular process V sacral vertebra. These processes, called sacral horns (cornua sacralia), serve for articulation with the sacrum coccyx. Sacral horns restrict the sacral gap (hiatus sacralis) - exit the sacral canal.

Coccyx (os coccygis) consists of 3-5 immature spine (vertebrae coccygeae) with (except I) form bone oval bodies, finally ossify at a later age. The body I have coccygeal vertebra towards the side protuberances, which are the rudiments of the transverse processes; above this vertebra are modified superior articular process - coccygeal horns (cornua coccygea), which are connected to the sacral horns. By birth the coccyx is the rudiment of the caudal skeleton.






List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)