After mating, the fertilized eggs may be laid by the mother, or they may develop either partially or fully inside the mother. The young get their nourishment either from a yolk sac or other methods, which are described in more detail below. Of the approximately 400 species of sharks, about 40% lay eggs. This is called oviparity. When the eggs are laid, they are in a protective egg case (which sometimes washes up on the beach and is commonly called a mermaid's purse).
X-rays: X-rays show the bones of the cervical spine. Most of the soft tissue structures of the spine, such as the nerves, discs, and muscles, do not show up on x-ray. X-rays can show problems that affect the bones, such as infection, fractures, or tumors of the bones.his shows up as weakness in the muscles the nerve goes to, numbness in the skin that the nerve goes to and pain where the nerve travels. In the neck, this condition is called cervical radiculopathy. Let's look at the different causes of cervical radiculopathy.
Large blood vessels, nerves, tendons, ligaments, and cartilage also comprise the lumbar spine. An X-ray uses small amounts of radiation to view the bones of the body. When it is focused on the lower spine, an X-ray can help detect abnormalities, injuries, or diseases of the bones in that area.According to the Mayo Clinic, a lumbar spine X-ray can show whether you have arthritis or broken bones in your back, but it cannot show other problems with the muscles, nerves, or discs.n X-ray is a useful test for many conditions. It can help your doctor understand the cause of chronic back pain or view the effects of injuries, disease, or infection. Your doctor may order a lumbar spine X-ray to diagnose: 1  birth defects that affect the spine.