Divisions of the human spine: the structure
The spine is an element of the human skeleton, which, on the one hand, is the support of the body, is involved in motor processes, on the other hand, protects the spinal cord from damage - a part of the human central nervous system. In our article we consider the anatomical structure of the human spine, its departments and functions.
The concept of the spine. Functions
The vertebral column consists of vertebrae, in an adult they are 33-34. The vertebrae are connected to each other through cartilage, joints and ligaments. Anatomically between the vertebrae are cartilage layers - intervertebral discs, which are designed to ensure the mobility of the spine.
The constituent elements are combined into groups (sections) of the human spine:
• cervical region;
• sacral region;
Grouped vertebrae have the same structure and perform the same function. However, there are small anatomical and functional differences between some vertebrae from different sections.
For each group of vertebrae, united in parts of the human spine, there is a generally accepted notation. In accordance with accepted standards, the seven vertebrae of the cervical region are denoted by the letters C1-C7; twelve elements of the thoracic - letters Th1-Th12; five lumbar vertebrae - L1-L5; sacral region denoted by the letters S1-S5; vertebrae coccygeal department - their number varies from three to five - the letters Co1-Co5.
Each vertebra is a bone tissue and is anatomically formed by a body, an arc, and three types of processes:
• spinous, located behind the arc;
• transverse processes located on the sides of the vertebral arch;
• the upper and lower articular processes located above and below the arc.
The body and the arc form between them a space - a vertebral foramen. The body performs the function of support. The processes connect the vertebrae with each other, and are also the basis for the attachment of muscles. The openings of each vertebra merge with each other and form a single tunnel - the spinal canal, in which the spinal cord is located. Besides,At the base of each articular process are vertebral notches, which form intervertebral foramina, penetrated by blood vessels and nerves of the spinal cord.
The names of the vertebrae are the same with the names of the spine, which include. However, some of the vertebrae have individual names.
Spinal curvatures: lordosis
We remember that the human spine consists of sections, and the spinal column is not even, but has two bends - lordosis and kyphosis.
Lordosis is represented by the cervical and lumbar parts of the spine, i.e. these are the sections that are bent forward. Kyphosis - bending of the spine back - is represented by the thoracic and sacral parts of the spine. In general, the bends of the vertebral column allow the person to maintain balance during sharp gestures.
Lordosis is classified into:
• physiological - provided anatomically, that is, laid by nature;
• pathological - acquired during life due to injuries or serious diseases.
In turn, pathological lordosis is classified into primary and secondary. The first form of pathological lordosis is usuallyoccurs on the background of tumors and inflammatory processes of the spine; secondary lordosis is the result of congenital pathology of the hip (dislocation).
Pathological lordosis can be identified by external signs. A person suffering from this disease has an incorrect posture: legs are unnaturally apart in the knees, and the flat chest passes into a bulging stomach. In addition to the aesthetic deformity, this pathology leads to malfunctioning of the internal organs, poor well-being of the patient, impaired metabolism.
Like lordosis, kyphosis is divided into physiological and pathological. Physiological kyphosis is the norm established by nature - a bend that affects the thoracic and sacral parts of the human spine. Pathological form of kyphosis - a pathology that occurs on the background of injuries or severe concomitant diseases. Suspicions of kyphosis may cause external signs - slouching, in neglected conditions - a hump.Diagnosis of pathology is carried out using X-ray. Kyphosis must be treated promptly, because a neglected disease can lead to serious disruption of the functioning of the whole body - deformities of the vertebrae, changes in the mobility of the ribs, and atrophy of the intercostal muscles.In accordance with the reasons due to which the disease occurs, there are:
• congenital kyphosis caused by abnormal development of the vertebral body;
• genotypic kyphosis, inherited from generation to generation;
• mobile kyphosis, occurring against the background of weak spinal muscles;
• rachitic kyphosis that occurs in young children with rickets;
• senile kyphosis in elderly people;
• tuberculosis kyphosis occurs on the background of a serious disease - bone tuberculosis.
The human cervical spine is formed by seven vertebrae. Thanks to this group of vertebrae, the most mobile of all, turns and various head movements are possible. The first two vertebrae have individual names and an anatomical structure different from the others. The first vertebra, the atlas, is only two arcs, with no body. The vertebra is attached to the skull on the one hand, on the other - it connects to the second cervical vertebra - the epistrophy.
Due to the fact that the vertebrae of the cervical spine are the least stressed relative to the other components of the spinal column, their body is small.In the transverse processes there are holes pierced by blood vessels - the vertebral artery and the vertebral vein. Near the hole is a groove with a spinal nerve. A distinctive feature of the seventh cervical vertebra is an elongated spinous process, so that this vertebra is well defined by touch.
The human thoracic spine is represented by twelve vertebrae with a larger body size in comparison with the vertebrae of the cervical spine.In general, as you move along the spine from the neck to the tailbone, the size of the vertebrae changes upwards. This is due primarily to the magnitude of the load experienced by the vertebrae when a person moves.
It is known that the human skeleton has twelve pairs of ribs, ten of which are attached to the spine and to the sternum, forming the rib cage. The remaining two pairs of rib bones are free. The body of each thoracic vertebra has an anatomical hemofibus - upper and lower. Accordingly, when articulating the lower polyamka of one vertebra with the upper polyamka of the second vertebra, a full-fledged fossa is formed - the place where the rib attaches to the spine.
However, the anatomy of the thoracic vertebrae is not the same.For example, in the body of the first vertebra there is a fossa, to which the first edge is attached, and a half-hole that connects to the second edge. But the tenth vertebra, on the contrary, has only one pole.
The lumbar spine of a person is represented by five vertebrae. The dimensions of the vertebral bodies are disproportionate — width is greater than height. The lumbar spine has the largest load during human movements, which is directly related to the low mobility of the vertebrae of the thoracic and sacral parts. Accordingly, the lumbar vertebrae are the largest of all the components of the spine. They, together with the muscles of the waist, work as shock absorbers. However, the ability to smooth out sharp movements with the age of a person fades away.
The vertebrae of this part of the spine form lordosis, which is formed in infancy, when a person learns to stand and then walk. The arc of a vertebra on both sides forms a vertebral foramen. To both sides of the arc, the processes, elements of undeveloped ribs - the so-called rudiments. By the way, the diameter of the vertebral foramen narrows as it moves along the spine from the first lumbar vertebra to the fifth. This is due to the structural features of the spinal cord.
Hypothermia, inflammation, vertebral injuries of the lumbar spine can lead to irreversible processes in the spine, painful pain, the development of various pathological conditions.
The human spinal sections discussed above are formed by a set of individual vertebrae, grouped together. The sacral region of the human spine, the sacrum, is formed by a rather large, triangle-like bone, located in the lower spinal column, in the pelvic region, between the two pelvic bones. The sacral bone has a concave shape and clearly defined transverse lines — the places where five once separate vertebrae of the sacral region have fused.
The lateral areas of the bones are wide at the top and narrowed downwards. On the side surfaces there are many L-shaped joints, through which the sacral bone is attached to the pelvic. Movement associated with bends and turns, provided the mobility of the pelvic joints. However, at the same time, an increased load is placed on these bones.
The base of the sacrum is turned upwards, in the direction of fusion with the fifth lumbar vertebra, where the cape is located - a projection directed into the pelvic cavity.The top of the sacrum has an oval surface and is directed downwards, in the direction of connection with the coccyx. In addition, through the sacral bone passes the sacral canal, filled with nerve processes.
If we compare the sacrum of the skeleton of the female body and the male, then it can be noted that the sacral bone of a woman is wider and at the same time shorter, has a smaller bend radius.
The coccyx region of the human spine is the lowest group of three to five intergrown vertebrae with rudimentary signs. In fact, the tailbone is a single bone, in shape resembling a pyramid, the base of which is at the top, and the tip is facing down.
The first vertebra of the department is characterized by underdeveloped articular processes, referred to as the coccygeal horns. In conjunction with the sacral horns, the processes form a sacrococcygeal junction. In addition, underdeveloped transverse processes extend from the lateral surfaces of the first vertebra. By the way, the rest of the elements of this department are missing. During childbirth in women, the tailbone can influence the size of the birth canal - increase them by deflecting it backwards.
The coccyx spine performs a very important function in the body. The first vertebrae of the coccyx are attached to the muscles and ligaments that ensure the work of the urinary organs and intestinal sections. To the coccygeal vertebrae, adjacent gluteal muscle bundles, providing mobility of the thigh. In addition, the coccygeal spine is the fulcrum in the distribution of the load on the pelvic structures.
Thus, in the materials of our article you can find information on many issues related to the structure and functioning of the spinal column, in particular, how many departments in the human spine, how the vertebra is anatomically arranged, what pathologies arise when the spinal column is incorrectly formed and developed.
Summarizing all the above, I would like to note the main thing. The spine is the most important element of the human skeleton, which is not only involved in the motor processes, ensuring the balance of the body, but also has a direct impact on the performance of all internal organs and systems.