Air embolism and veins is greater than atmospheric pressure, an air embolus does not often happen when a blood vessel is injured. In the veins above the heart, such as in the head and neck, the venous pressure may be less than atmospheric and an injury may let air in. This is one reason why surgeons must be particularly careful when operating on the brain, and why the head of the bed is tilted down when inserting or removing a central venous catheter from the jugular or subclavian veins. When air enters the veins, it travels to the right side of the
Basivertebral veins vertebral plexuses. The basivertebral veins become greatly enlarged in advanced age. Basivertebral veins The basivertebral veins are veins within the vertebral column. They are contained in large, tortuous channels in the substance of the bones, similar in every respect to those found in the diploë of the cranial bones. They emerge from the foramina on the posterior surfaces of the vertebral bodies. They communicate through small openings on the front and sides of the vertebral bodies with the anterior external vertebral plexuses, and converge behind to the principal canal, which is sometimes double toward its posterior part, and open by