Spinal canal
Encyclopedia
The spinal canal is the space in vertebrae through which the spinal cord
passes. It is a process of the dorsal human body cavity. This canal is enclosed within the vertebral foramen
of the vertebrae. In the intervertebral spaces, the canal is protected by the ligamentum flavum posteriorly and the posterior longitudinal ligament
anteriorly.
The outermost layer of the meninges
, the dura mater
, is closely associated with the arachnoid
which in turn is loosely connected to the innermost layer of the meninges
, the pia mater
. The meninges divide the spinal canal into the epidural space
and the subarachnoid space
. The pia mater
is closely attached to the spinal cord
. A subdural space
is generally only present due to trauma and/or pathological situations. The subarachnoid space
is filled with cerebrospinal fluid
and contains the vessels that supply the spinal cord
, namely the anterior spinal artery
and the paired posterior spinal arteries, accompanied by a corresponding spinal veins. The spinal arteries form anastomoses known as the vasocorona of the spinal cord. The epidural space contains loose fatty tissue, and a network of large, thin-walled blood vessels called the internal vertebral venous plexuses
.
The spinal canal was first described by Jean Fernel
.
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
passes. It is a process of the dorsal human body cavity. This canal is enclosed within the vertebral foramen
Vertebral foramen
In a typical vertebra, the vertebral foramen is the foramen formed by the anterior segment , and the posterior part, the vertebral arch....
of the vertebrae. In the intervertebral spaces, the canal is protected by the ligamentum flavum posteriorly and the posterior longitudinal ligament
Posterior longitudinal ligament
The posterior longitudinal ligament is situated within the vertebral canal, and extends along the posterior surfaces of the bodies of the vertebræ, from the body of the axis, where it is continuous with the membrana tectoria, to the sacrum....
anteriorly.
The outermost layer of the meninges
Meninges
The meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura...
, the dura mater
Dura mater
The dura mater , or dura, is the outermost of the three layers of the meninges surrounding the brain and spinal cord. It is derived from Mesoderm. The other two meningeal layers are the pia mater and the arachnoid mater. The dura surrounds the brain and the spinal cord and is responsible for...
, is closely associated with the arachnoid
Arachnoid
Arachnoid may refer to:*Relating to arachnids*Arachnoid mater, a layer of the meninges, membranes that contain the central nervous system*Arachnoid , a geological structure found only on the planet Venus...
which in turn is loosely connected to the innermost layer of the meninges
Meninges
The meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura...
, the pia mater
Pia mater
Pia mater often referred to as simply the pia, is the delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord. The word finds its roots in Latin, meaning literally "tender mother." The other two meningeal membranes are the dura mater and the arachnoid mater....
. The meninges divide the spinal canal into the epidural space
Epidural space
In the spine, the epidural space is the outermost part of the spinal canal. It is the space within the canal lying outside the dura mater...
and the subarachnoid space
Subarachnoid space
In the central nervous system, the subarachnoid cavity is the interval between the arachnoid membrane and pia mater....
. The pia mater
Pia mater
Pia mater often referred to as simply the pia, is the delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord. The word finds its roots in Latin, meaning literally "tender mother." The other two meningeal membranes are the dura mater and the arachnoid mater....
is closely attached to the spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
. A subdural space
Subdural space
The subdural space is an artificial space created by the separation of the arachnoid mater from the dura mater as the result of trauma, pathologic process, or the absence of cerebrospinal fluid as seen in a cadaver. In the cadaver, due to the absence of cerebrospinal fluid, the arachnoid mater...
is generally only present due to trauma and/or pathological situations. The subarachnoid space
Subarachnoid space
In the central nervous system, the subarachnoid cavity is the interval between the arachnoid membrane and pia mater....
is filled with cerebrospinal fluid
Cerebrospinal fluid
Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...
and contains the vessels that supply the spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
, namely the anterior spinal artery
Anterior spinal artery
In human anatomy, the anterior spinal artery is the blood vessel that supplies the anterior portion of the spinal cord. It arises from branches of the vertebral arteries and is supplied by the anterior segmental medullary arteries, including the artery of Adamkiewicz, and courses along the anterior...
and the paired posterior spinal arteries, accompanied by a corresponding spinal veins. The spinal arteries form anastomoses known as the vasocorona of the spinal cord. The epidural space contains loose fatty tissue, and a network of large, thin-walled blood vessels called the internal vertebral venous plexuses
Internal vertebral venous plexuses
The internal vertebral venous plexuses lie within the vertebral canal in the epidural space, and receive tributaries from the bones and from the medulla spinalis....
.
The spinal canal was first described by Jean Fernel
Jean Fernel
Jean François Fernel was a French physician who introduced the term "physiology" to describe the study of the body's function. He was the first person to describe the spinal canal...
.
