The human body supports the axial bone - the spine

Features of the spine model
The spine model is an intuitive teaching model in human anatomy teaching. It is made of PVC material. The model shows all the main features of each vertebra, including vertebrae, nerve roots, vertebral arteries, divided intervertebral discs, vertebral transverse processes and vertebral sections. Ideal teaching model for chiropractic, orthopaedic and other medical specialties
The human spine consists of 24 vertebrae (7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae), 1 sacrum and 1 coccyx connected by ligaments, joints and intervertebral discs. The upper end of the spine supports the skull, lowers the hip bone, attaches to the rib cage, and serves as the back wall of the thoracic, abdominal and pelvic cavities. Inside the spine there is a longitudinal spinal canal that houses the spinal cord. The spine has the functions of supporting the trunk, protecting the internal organs, protecting the spinal cord and carrying out movement. The interior of the spine forms a longitudinal spinal canal from top to bottom, which contains the spinal cord.
Spine Model Features

front view

The vertebral body gradually widens from top to bottom, and the second sacral vertebra is the widest, which is related to the load-bearing of the vertebral body. From below the auricular surface of the sacrum, the gravity is transmitted to the lower limb bones, and the volume gradually decreases.

rear view

The spinous processes of the vertebrae coherent into a longitudinal ridge, located on the midline of the back. The cervical spinous process is short and bifurcated. Near horizontal position; thoracic vertebrae spinous processes are slender, obliquely posterior and lower, arranged in imbricate; lumbar vertebrae spinous processes are plate-like horizontally backward.

side view

It can be seen that there are four physiological curvatures of the neck, thoracic, lumbar, and sacrum. The cervical and lumbar curvatures are convex forward, and the thoracic and sacral curvatures are convex backward. Under normal circumstances, the spine has four curvatures, which are S-shaped when viewed from the side, that is, the cervical spine. lordosis, thoracic kyphosis, lumbar lordosis, and sacral kyphosis.
load
The load on the spine is the sum of body weight, muscle tone, and extrinsic load above a certain segment. Spinal segments in different parts bear different loads. Because the lumbar spine is in the lowest position of the spine, the load is quite large, and it is the junction of the movable segment and the fixed segment, so there are many opportunities for injury, and it becomes the most common part of low back pain. There are static and dynamic loads on the spine. Static refers to the load and internal balance of the spine when standing, sitting or lying down, while dynamic refers to the force exerted by the body on the spine in an active state. These loads require corresponding joints, ligaments and muscles to maintain.