In human anatomy, the spinal canal, vertebral canal or spinal cavity is an elongated body cavity enclosed within the dorsal bony arches of the vertebral column, which contains the spinal cord, spinal roots and dorsal root ganglia. It is a process of the dorsal body cavity formed by alignment of the vertebral foramina. Under the vertebral arches, the spinal canal is also covered anteriorly by the posterior longitudinal ligament and posteriorly by the ligamentum flavum. The potential space between these ligaments and the dura mater covering the spinal cord is known as the epidural space. Spinal nerves exit the spinal canal via the intervertebral foramina under the corresponding vertebral pedicles.
In anatomy, the epidural space is the potential space between the dura mater and vertebrae (spine).
In human anatomy, the abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.
The inferior ophthalmic vein is a vein of the orbit that - together with the superior ophthalmic vein - represents the principal drainage system of the orbit. It begins from a venous network in the front of the orbit, then passes backwards through the lower orbit. It drains several structures of the orbit. It may end by splitting into two branches, one draining into the pterygoid venous plexus and the other ultimately into the cavernous sinus.
The pterygoid plexus is a fine venous plexus upon and within the lateral pterygoid muscle. It drains by a short maxillary vein.
The ligamenta flava are a series of ligaments that connect the ventral parts of the laminae of adjacent vertebrae. They help to preserve upright posture, preventing hyperflexion, and ensuring that the vertebral column straightens after flexion. Hypertrophy can cause spinal stenosis.
The posterior longitudinal ligament is a ligament connecting the posterior surfaces of the vertebral bodies of all of the vertebrae of humans. It weakly prevents hyperflexion of the vertebral column. It also prevents posterior spinal disc herniation, although problems with the ligament can cause it.
The lumbar veins are four pairs of veins running along the inside of the posterior abdominal wall, and drain venous blood from parts of the abdominal wall. Each lumbar vein accompanies a single lumbar artery. The lower two pairs of lumbar veins all drain directly into the inferior vena cava, whereas the fate of the upper two pairs is more variable.
The external vertebral venous plexuses consist of anterior and posterior plexuses which anastomose freely with each other. They are most prominent in the cervical region where they form anastomoses with the vertebral, occipital, and deep cervical veins.
The basivertebral veins are large, tortuous veins of the trabecular bone of vertebral bodies that drain into the internal and external vertebral venous plexuses.
The intervertebral veins accompany the spinal nerves through the intervertebral foramina to drain the internal vertebral venous plexuses into the external vertebral venous plexuses. They drain into vertebral vein, intercostal veins, lumbar veins, and lateral sacral veins. Upper posterior intercostal veins may additionally drain via brachiocephalic vens. They may drain to ascending lumbar veins. They may drain into the inferior vena cava directly, reaching it by winding around the surface of the vertebral body.
The spinal veins are situated in the pia mater and form a minute, tortuous, venous plexus.
The Batson venous plexus is a network of valveless veins in the human body that connect the deep pelvic veins and thoracic veins to the internal vertebral venous plexuses. Because of their location and lack of valves, they are believed to provide a route for the spread of cancer metastases. These metastases commonly arise from cancer of the pelvic organs such as the rectum and prostate and may spread to the vertebral column or brain. The plexus is named after anatomist Oscar Vivian Batson, who first described it in 1940. Batson's plexus is part of the Cerebrospinal venous system.
Anterior spinal veins are veins that receive blood from the anterior spinal cord.
The following outline is provided as an overview of and topical guide to human anatomy:
The epidural venous plexus is a venous plexus embedded within the epidural fat of the vertebral canal. It is situated within the anterior epidural space. The plexus extends from the skull base to the sacrum. It is surrounded by sparse fat. It drains into the cavernous sinus of the cranial cavity; it also communicates with the radicular veins.
The cerebrospinal venous system (CSVS) consists of the interconnected venous systems of the brain and the spine.
Each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species.
The marginal sinus is a dural venous sinus surrounding the margin of the foramen magnum inside the skull, accommodated by the groove for marginal sinus. It usually drains into either the sigmoid sinus, or the jugular bulb. It communicates with the basilar venous plexus anteriorly, and the occipital sinus posteriorly ; it may form extracranial communications with the internal vertebral venous plexuses, or deep cervical veins.
