Periodontal tissue is composed of periodontal ligament, alveolar bone and gum (commonly known as dental pulp). Its main function is to support, fix and nourish teeth.
2. Epidural cavity is a narrow space between dura mater and periosteum and ligamentum flavum on the inner surface of spinal canal, which is called epidural cavity. There are loose connective tissue, adipose tissue, lymphatic vessels and venous plexus in spinal canal, and spinal nerve roots pass through it. Not communicating with the lower skull, but slightly negative pressure. Clinically, lumbar puncture can be performed to inject anesthetic into this space to anesthetize the spinal nerve roots.
Extended data
Epidural cavity, also known as epidural cavity, is located between the dura mater and periosteum on the inner surface of spinal canal, and contains lymphatic vessels, a lot of adipose tissue and venous plexus. The venous plexus receives blood from the veins of the spinal cord, spinal cord sac and spine.
The epidural space does not enter the skull upward, and it is in a state of slight negative pressure, with spinal nerve roots passing through it. In clinical epidural anesthesia, drugs are injected into the epidural space to block the conduction of spinal nerves.
Epidural block refers to injecting local anesthetic into the epidural space to temporarily block the conduction of spinal nerve roots through the dura mater at the spinal nerve roots. If local anesthetic is injected into sacral canal through sacral canal hiatus, it is called sacral canal block.