Nervous System - Pathology

Pathology

Main article: Neurology See also: Psychiatry

The central nervous system is protected by major physical and chemical barriers. Physically, the brain and spinal cord are surrounded by tough meningeal membranes, and enclosed in the bones of the skull and spinal vertebrae, which combine to form a strong physical shield. Chemically, the brain and spinal cord are isolated by the so-called blood–brain barrier, which prevents most types of chemicals from moving from the bloodstream into the interior of the CNS. These protections make the CNS less susceptible in many ways than the PNS; the flip side, however, is that damage to the CNS tends to have more serious consequences.

Although nerves tend to lie deep under the skin except in a few places such as the ulnar nerve near the elbow joint, they are still relatively exposed to physical damage, which can cause pain, loss of sensation, or loss of muscle control. Damage to nerves can also be caused by swelling or bruises at places where a nerve passes through a tight bony channel, as happens in carpal tunnel syndrome. If a nerve is completely transected, it will often regenerate, but for long nerves this process may take months to complete. In addition to physical damage, peripheral neuropathy may be caused by many other medical problems, including genetic conditions, metabolic conditions such as diabetes, inflammatory conditions such as Guillain–Barré syndrome, vitamin deficiency, infectious diseases such as leprosy or shingles, or poisoning by toxins such as heavy metals. Many cases have no cause that can be identified, and are referred to as idiopathic. It is also possible for nerves to lose function temporarily, resulting in numbness as stiffness—common causes include mechanical pressure, a drop in temperature, or chemical interactions with local anesthetic drugs such as lidocaine.

Physical damage to the spinal cord may result in loss of sensation or movement. If an injury to the spine produces nothing worse than swelling, the symptoms may be transient, but if nerve fibers in the spine are actually destroyed, the loss of function is usually permanent. Experimental studies have shown that spinal nerve fibers attempt to regrow in the same way as nerve fibers, but in the spinal cord, tissue destruction usually produces scar tissue that cannot be penetrated by the regrowing nerves.

Read more about this topic:  Nervous System

Other articles related to "pathology":

Soft Tissue Pathology
... Soft tissue pathology is the subspecialty of surgical pathology which deals with the diagnosis and characterization of neoplastic and non-neoplastic diseases of the soft tissues, such as ... such as immunohistochemistry, electron microscopy, and molecular pathology techniques are sometimes employed to obtain a definitive diagnosis ...
The American Journal Of Surgical Pathology
... The American Journal of Surgical Pathology is a peer-reviewed medical journal covering surgical pathology ...
Ludwig Aschoff
... Ludwig Aschoff was appointed professor for pathology at the University of Göttingen in 1901 ... Aschoff was interested in the pathology and pathophysiology of the heart ... "Pathology of constitution" invented by him became a special branch of research of National Socialist doctors under the name of "military pathology" ...
Pathology As A Medical Specialty
... Pathology is a core discipline of medical school and many pathologists are also teachers ... Although the medical practice of pathology grew out of the tradition of investigative pathology, most modern pathologists do not perform original research ... Pathology is a unique medical specialty ...

Famous quotes containing the word pathology:

    It is often said that Poland is a country where there is anti-semitism and no Jews, which is pathology in its purest state.
    Bronislaw Geremek (b. 1932)