The spine supports the head and upper torso. This sturdy, flexible chain of bones called vertebrae. Connection between two adjacent vertebrae (intervertebral discs) provide only limited movement, but on the whole spine is very mobile.
The spinal column extends from the base of the skull to the coccygeal horn - the junction with his pelvis. Through it, the mass of the head and body is distributed to his feet. The bones of the spinal column surrounds and protects the spinal cord, which starts from the lower part of the brain. The spine has an S-shaped (it gives him 4 bending), which is visible in the lateral projection. He strong, flexible, provides balance, body positioning directly above the feet, as well as compensate for the stresses of movement.
In adults, there are 26 vertebrae, although two of them - the sacrum and coccyx, formed by several fused vertebrae. All the same vertebral body plan. Vertebra has the form of the bone-ring surrounding the vertebral opening, through which the spinal cord. Thickened portion of the vertebral body and forms the front of the ring, is located behind the arc vertebra. Located on the arc processes (two transverse and one spinous), to which are attached ligaments and muscles of the back, fixing the position of the spine, not letting make too sharp slopes and keeping it upright. Between the vertebrae are intervertebral diskihryaschevye education, filled with jelly-like substance that allow vertebrae slightly offset from each other in walking, jumping or running.
In accordance with the location, size, shape and functions performed vertebrae are divided into 5 types. Seven vertebrae form a small flexible neck. The top-most of them, atlas, skull and connected to provide an offset (sternocleidomastoid movement) of the head forward. Atlanta is associated with the adjacent joint cylindrical, second - axial cervical vertebra, which ensures a head turning from side to side. This is followed by 12 thoracic vertebrae that form the middle of the spinal column. Each of them is connected to the ribs. The five lumbar vertebrae carry the bulk of the upper torso and head. The triangular shape is formed by five fused sacrum and firmly connected with the bones of the pelvis vertebrae. The coccyx, or tail bone, formed by four fused vertebrae and the coccygeal end horn.
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)