The spinal cord is an extension of the medulla oblongata. It has two main functions:
- Route the afferent and efferent between the CNS and the rest of the body
- Treatment of partial information by spinal reflexes.
It develops from the caudal portion of embryonic neural tube. Distinguish a few weeks, two separate parts in the gray matter: the basal plate and alar plate, separated by a furrow, eventually becoming the central canal. As it grows, the blades extend and produce the gray mass of adult marrow. The white outer marrow is formed from neural axons.
The bone extends from the foramen magnum to the first or second lumbar vertebra. Hence, a filament fiber, fossil embryogenesis, from the meninges, extends to the coccyx, the terminal filum.
31 pairs of spinal nerves exit the spinal cord and innervate the body. She has two bulges, one from which the cervical nerves of upper limbs, forming the brachial plexus, the other from which the lumbar nerves of the lower limbs forming the lumbosacral plexus.
It has a slightly flattened and has two grooves, the median anterior and posterior midline.
Composition of the spinal cord:
Like the brain, spinal consists essentially of “white” and substance “gray”:
The white matter contains the myelinated neurons extensions: It completely surrounds the gray matter which way, is framed into three parts, called posterior, lateral and anterior. These cables, made up of groups of neurons called a type beams carry impulses to a specific destination (beams spinal ascending and descending)
The gray matter contains the bodies of neurons and the neuroglia: It has roughly the shape of an H, the side deck is appointing gray commissure, dug a thin channel called the central canal, extension of the 4th ventricle. The ‘pipes’ of H divide into pairs of posterior and anterior horns. Note that exists in some regions, particularly the chest, lateral horns. (more…)