A spinal segment is defined by dorsal roots entering and ventral roots exiting the cord, (i.e., a spinal cord section that gives rise to one spinal nerve is considered as a segment.)
What is a spinal segment definition?
Medical Definition of spinal segment
: a segment of the spinal cord including a single pair of spinal nerves and representing the spinal innervation of a single primitive metamere.
What are the segments of the spine?
What are the spine segments?
- Cervical (neck): The top part of the spine has seven vertebrae (C1 to C7). …
- Thoracic (middle back): The chest or thoracic part of the spine has 12 vertebrae (T1 to T12). …
- Lumbar (lower back): Five vertebrae (L1 to L5) make up the lower part of the spine.
What are the five segments of the spinal cord?
As mentioned above, our vertebrae are numbered and divided into five regions: cervical, thoracic, lumbar, sacrum, and coccyx.
What is length of spinal cord?
The spinal cord is about 18 inches (45 centimeters) in length and is relatively cylindrical in shape. The cervical (neck) and lumbar (lower back) segments house the spinal cord’s two areas of enlargement. A fibrous band called the filum terminale begins at the tip of the conus medullaris and extends to the pelvis.
How do you count vertebral segments?
When counting vertebral segments, be mindful that a single interspace sits between two vertebral segments. For instance, the span C6-T2 contains four vertebral segments (C6, C7, T1, and T2) and three vertebral interspaces (C6/C7, C7/T1, and T1/T2).
What is difference between spinal cord and spinal nerve?
Like the brain, the spinal cord is covered by three layers of tissue (meninges). Spinal nerves: Emerging from the spinal cord between the vertebrae are 31 pairs of spinal nerves. Each nerve emerges in two short branches (roots): One at the front (motor or anterior root) of the spinal cord.
What is the difference between white and GREY matter in the spinal cord?
Grey matter is distinguished from white matter in that it contains numerous cell bodies and relatively few myelinated axons, while white matter contains relatively few cell bodies and is composed chiefly of long-range myelinated axons. The colour difference arises mainly from the whiteness of myelin.