What is a Cervical Disc?

Cervical intervertebral disc (Cervical intervertebral disc): divided into the nucleus pulposus in the central part, full of elastic gelatinous substance; the fibrous ring in the peripheral part, arranged by multiple layers of fibrocartilage rings in a concentric circle. The fibrous ring of the neck is thick before the thin, and the nucleus pulposus easily protrudes to the posterolateral side, protruding into the spinal canal or intervertebral foramen, compressing the spinal cord or spinal nerve-cervical disc herniation.

Cervical intervertebral disc

Right!

Cervical intervertebral disc (Cervical intervertebral disc): divided into the nucleus pulposus in the central part, full of elastic gelatinous substance; the fibrous ring in the peripheral part, arranged by multiple layers of fibrocartilage rings in a concentric circle. The fibrous ring of the neck is thick before the thin, and the nucleus pulposus easily protrudes to the posterolateral side, protruding into the spinal canal or intervertebral foramen, compressing the spinal cord or spinal nerve-cervical disc herniation.

Definition of cervical disc

The cervical intervertebral disc is a sealed body composed of a cartilage plate, a fibrous ring, and a nucleus pulposus, located between two vertebrae of the cervical spine. There are upper and lower cartilage plates, which are transparent cartilage covering the vertebral body, and the bone surface in the middle of the condyle below. The upper and lower cartilage plates seal the nucleus pulposus together with the fibrous ring. The annulus fibrosus is composed of fibrocartilage of collagen fiber bundles, which are located around the nucleus pulposus. The fiber bundles of the fiber ring obliquely cross and overlap each other, so that the fiber ring becomes a solid structure that can withstand large bending and torsional loads.

Cervical intervertebral disc

The cervical vertebrae, intervertebral discs and the anterior and posterior longitudinal ligaments are closely connected. The intervertebral disc is located between adjacent vertebral bodies, and the anterior and posterior longitudinal ligaments are located anterior and posterior to the vertebral body, respectively.

The anterior longitudinal ligament is the longest ligament in the body. It is thick, wide, and tough. The upper end is narrow, attached to the anterior nodule of the atlas, and the lower end stops in front of the first and second sacrum. The elasticity and tension of the anterior longitudinal ligament are very large. When the spine is flexed, it can maintain its shape and restrict the spine's hyperextension motion. The posterior longitudinal ligament is relatively slender and although it is also very tough, it is weaker than the anterior longitudinal ligament and is located behind the vertebral body and is the anterior wall of the spinal canal. The upper end starts from the second cervical spine, moves up to the tunica, down to the sacral canal, and moves to the deep posterior ligamentum ligament.

The vertebral arch is connected by intervertebral joints and ligaments. The upper and lower articular surfaces of adjacent vertebrae constitute an intervertebral joint, which is connected by a thin, loose joint capsule ligament, and there is no ligament between the transverse processes of the cervical vertebra. There are yellow ligaments between the lamina, showing. There are interspinous ligaments and supraspinous ligaments between the spinous processes to connect them with each other. In the neck, the supraspinous ligament forms a collar ligament. The ligament is a triangular elastic fibrous membrane. Its bottom surface is attached to the occipital bulge and occipital condyle upwards, and its tip moves down to the supraspinous ligament. The ligament assists the neck muscles to support the head and neck, and has the effect of resisting cervical spine flexion.

Cervical intervertebral disc

There is no intervertebral disc between the first and second cervical vertebrae, and the dentate process of the second cervical vertebra, the pivotal vertebra, extends up into the atlas, and forms the atlantoaxial joint with the joint surface behind the anterior arch of the atlas. The tip of the tooth process of the vertebra is called the tooth process tip, which is the attachment part of the tooth tip ligament, and the wing-shaped ligaments are attached on both sides. At the back of the tooth process, there is an atlantotransverse ligament, which is thick and tough; a longitudinal fiber bundle is issued from the middle to the bottom, attaching to the anterior edge of the foramen magnum, and connecting downward to the back of the vertebral body of the vertebra. These two fiber bundles together with the transverse ligament of the atlas form the atlas cruciate ligament.

Cervical intervertebral disc cervical motion range

In order to adapt to the visual, auditory and olfactory stimuli, the cervical spine needs to have large and sharp mobility. Therefore, the range of motion of the cervical spine is much larger than that of the thoracic spine and lumbar spine, such as forward and backward flexion, lateral flexion, left and right rotation, and the circular movement formed by the above-mentioned movements.

In medicine, the range of motion of a joint is called the degree of motion of the joint, and it is generally measured with a protractor. When measuring, the neck is naturally straight, and the chin is adducted. In general, the forward flexion and extension of the cervical spine (commonly known as bow and head) are 45 degrees. The forward and backward movements of the cervical spine are the result of forward and backward sliding of the intervertebral joints of the upper and lower vertebrae. Excessive forward flexion is restricted by the posterior longitudinal ligament, yellow ligament, neck ligament, and posterior cervical muscle group; excessive posterior extension is restricted by the anterior longitudinal ligament and anterior cervical muscle group. The flexion and extension of the cervical spine is mainly performed by the second to seventh cervical spine. The left and right lateral flexion are 45 degrees each, mainly relying on the contralateral joint capsule and ligaments to limit excessive lateral flexion. Lateral flexion is mainly performed by the middle cervical spine. The left and right rotations are each 75 degrees, which are mainly performed by the atlantoaxial joint. The circular movement is completed by the coherence of the above activities. The nodding movement occurred at the atlantooccipital joint; the shaking movement occurred at the atlantoaxial joint. Cervical spine activity varies greatly from individual to individual, related to age, occupation, and exercise. Neck movements are generally restricted with age.