a canal running in the centre of the neural arch of a vertebra
Answers
The arch encloses an opening, thevertebral foramen, which helps to forma canal in which the spinal cord is housed. Protruding from the posterior extreme of each neural arch is a spinous process and extending from the lateral edges of each arch are transverse processes.
The vertebral column is composed of a series of 31 separate bones known as vertebrae. There are seven cervical or neck vertebrae, 12 thoracic vertebrae, and five lumbar vertebrae. The sacrum is composed of five fused vertebrae, and there are two coccygeal vertebrae which are sometimes fused. In the normal adult there are four curvatures in the vertebral column in an anteroposterior plane. These serve to align the head with a vertical line through the pelvis . In the thoracic and sacral regions, these curves are oriented concave anterior and each is known as a kyphosis. In the lumbar and cervical regions the curves are convex anterior and each is known as a lordosis. These latter normal curvatures develop during childhood in association with lifting the head (cervical) and assuming upright sitting (lumbar) and they are thus known as secondary curvatures. The thoracic and sacral curvatures are the same in adult as they are in fetal life and they are known as primary curvatures. Exaggerated kyphosis or lordosis can occur under some normal conditions (e.g. increased lumbar lordosis in pregnancy). A curvature of the vertebral column in a mediolateral plane can occur pathologically and is known as a scoliosis