Spinal cord

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spinal cord is one of the parts of the CNS (central nervous system), connecting the body to the external environment and control its functions.It is because of the central nervous system, and various organs and systems of the person acting in concert, in response to the changes that occur in the environment.

Communication brain with bodies and limbs by using the spinal cord.It performs the introducer and reflex functions.

How is and where the spinal cord

structure of the department of the central nervous system is relatively simple.The spinal cord is formed by gray and white matter.White matter - a complex system of nerve fibers (myelin and unmyelinated) nerve tissue and blood vessels that are surrounded by a little connective tissue.Gray matter form nerve cell bodies with processes that do not have the myelin sheath.In the center of the spinal cord passes a channel which is filled with cerebrospinal fluid.With the internal organs and limbs of its many associated nerves, which are characterized by regular periodicity.

width reaches the spinal cord in the adult one and a half centimeters, length - 45 cm. Its average weight is '35

Located human spinal cord in the inner cavity of the spinal canal.Outwardly, it resembles a long cord with numerous branches.Its upper end with no sharp boundary is associated with the medulla oblongata in the region I of the cervical vertebrae, the lower level is located on I-II of the lumbar vertebrae.He goes to a terminal (spinal) thread.The upper end portions of the thread are fragments of neural tissue, but otherwise it is a connection form.Penetrating to the dura mater in the sacral canal, spinal string attached at its end.

are three membranes surrounding the spinal cord.The inner shell - soft (vascular), the average - the arachnoid and external - hard.From envelopes to the bone canal are ligaments that hold the spinal cord in a standing position.The space located between the inner and middle shells filled with cerebrospinal fluid.

Thus, the cavity of the spinal canal where the spinal cord is located, is filled with fatty tissue, cerebrospinal fluid, brain membranes and blood vessels.

longitudinal grooves divide the spinal cord on the right and left symmetrical halves.

in the spinal canal a short distance are the nerve roots.They emanate from each half to form two longitudinal rows.They leave the spinal canal through a hole foraminarnye.The spinal cord is characterized by a pronounced segmental.Segments refer to the part of the brain, which leave the spinal canal nerves emanating from them.Each segment innervates a particular region of the human body.

are five parts of the spinal cord.Shane form part of the eight segments chest - twelve segments, lumbar - five sacral - and five coccygeal - 1-3 segment.The segments of the cervical innervate the arms and neck, thoracic parts - the chest and abdomen, lumbar and sacral - legs, pelvic organs and perineum.Nerve roots extending below the level of the spinal cord closure innervate the lower half body including the pelvic organs.

numbness or motor function of a particular area of ​​the body may indicate that part of the spinal cord, which could result in damage.

In peripheral nerves from the spinal cord to the body's organs comes nerve impulses.They regulate the function of all organs.Sensory nerve fibers transmit information from tissues and organs to the spinal cord and central nervous system.