|MEDICAL ANIMATION TRANSCRIPT: |
Your spine is composed of individual bones called vertebrae. Your vertebrae form a protective tunnel called the spinal canal, which surrounds the spinal cord as it travels down the length of your spine. On each side of the spinal cord, spinal nerves exit the spinal canal through small, bony channels called neural foramina. Cervical spinal nerves travel through your neck, shoulders and arms. Between your skull and your ribcage are seven vertebrae that make up your cervical spine. Flexible pads, known as intervertebral disks, provide a cushion between your vertebrae for the range of movements your head and neck make every day. The cervical spine supports the weight of your head, allows your head to rotate and tilt, and helps you bend your neck. Cervical disc pressure increases when your neck bends forward, backward, and sideways. Intervertebral disks consist of a tough, outer ring of tissue called the annulus fibrosus, and a soft, jelly-like center called the nucleus pulposus. During a traumatic injury, your spine maybe forced forward, or hyperflexed, causing your vertebrae to compress the front of one or more of your cervical disks beyond normal limits. Hyperflexion of the neck is a common cause of cervical injury that occurs in motor vehicle accidents and some sports. As a result, your jelly-like nucleus pulposus is pushed backward into your annulus fibrosus, thinning your annulus and causing small tears. After a cervical disc injury, your annulus fibrosus begins to weaken and tear, and your nucleus pulposus becomes dry and stiff. Over time, these changes make your disk susceptible to further injury. As your intervertebral disk deteriorates, a weak annulus fibrosus can allow your nucleus pulposus to bulge, changing the disk's normal shape and flexibility. Depending on its size and location, the bulge may push on, or impinge, one of your spinal nerves or your spinal cord, causing pain and inflammation. Central disk bulges project backward into your spinal canal. Lateral disk bulges push into your neural foramen. Severe cervical disc injuries can tear open your annulus fibrosis. Pressure from your vertebrae may force the nucleus pulposus out of the torn annulus, causing a disk herniation. A herniated disk can impinge your spinal nerves or spinal cord, interrupt normal nerve signals, and cause symptoms such as pain, numbness, or weakness in one or both of your arms. Treatment for cervical disc injuries may include rest, anti-inflammatory medication, muscle relaxants, ice or heat applied to the injured area, physical therapy, steroid injections, and in more severe cases, surgery.