Term
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Definition
| An exceedingly complex arrangement of nerve cells and their fibers that extends through the body and receives, processes, and interprets sensory stimuli; initiates and coordinates voluntary muscular movement; regulates autonomic processes; carries out complex mental functions and operations; and is the seat of mood and emotions. |
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Term
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Definition
| Nerve cell- consists of a cell body containing a nucleus; one or more dendrites; and an axon. |
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Definition
| Short treelike process that is the receptive ending of the neuron. Conducts impulses towards the cell body (afferent process). |
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Term
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Definition
| The long process of a nerve fiber that conducts impulses away from the body of the nerve cell (efferent process). |
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Term
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Definition
| The point of contact between processes of two different cells. |
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Term
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Definition
| A thin layer of fatty white material that envelops the axons of some nerve cells. |
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Term
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Definition
| Serves as an electrical insulator. |
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Term
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Definition
| Nerve tissue consisting of many myelinated fibers. |
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Term
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Definition
| Tissue consisting chiefly of nerve cell bodies. |
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Term
| CENTRAL NERVOUS SYSTEM (CNS) |
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Definition
| Consists of the brain and spinal cord. |
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Term
| PERIPHERAL NERVOUS SYSTEM (PNS) |
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Definition
| Consists of the peripheral motor and sensory nerves and the autonomic nervous system. It comprises all nerve tissue outside the brain and spinal cord. |
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Term
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Definition
| Consists of two symmetric hemispheres and concerned with the higher mental processes. |
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Term
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Definition
| The surface of the cerebrum. Consists of gyri and sulci. Fissures divide each hemisphere into 4 lobes. |
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Term
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Definition
| The convexities (raised areas) of the cerebral cortex. |
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Term
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Definition
| The grooves between the gyri. |
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Term
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Definition
| Grooves deeper than the sulci. In the brain they form the 4 lobes. |
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Term
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Definition
| The anterior portion of the cerebral hemisphere. |
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Term
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Definition
| The lower lateral lobe of the cerebral hemisphere. |
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Term
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Definition
| The upper, central portion of the cerebral hemisphere. It's between the frontal and occipital lobes and above the temporal lobe. |
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Term
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Definition
| The most posterior portion on the cerebral hemisphere, forming a small part of its dorsolateral surface. |
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Term
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Definition
| Lies behind the cerebrum and looks like a smaller version of it. It's principal function is coordination of voluntary motor activity. |
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Term
| VENTRAL SURFACE OF THE BRAIN |
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Definition
| Front portion of the brain composed of the diencephalon (pineal body, thalamus, hypothalamus), mesencephalon (midbrain), pons, and medulla oblongata. |
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Term
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Definition
| Made up of the midbrain, pons, and medulla. Connects the brain to the spinal cord. |
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Term
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Definition
| Three protective membranes covering the brain and spinal cord. |
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Term
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Definition
| The outer layer of the meninges. It's in contact with the bony interior of the skull and spinal column. |
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Term
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Definition
| The middle layer of the meninges. |
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Term
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Definition
| The innermost layer of the meninges. It lies on the surface of the brain and spinal cord. |
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Term
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Definition
| The cavity in each cerebral hemisphere, derived from the cavity of the embryonic tube, containing cerebrospinal fluid and communicating with the third ventricle. |
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Term
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Definition
| A vertically disposed, ring-shaped space that contains cerebrospinal fluid and that communicates anteriorly with the lateral ventricles and caudally with the cerebral aqueduct within the diencephalon between the two thalami. |
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Term
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Definition
| A median, horizontally disposed, rhomboid cavity in the hindbrain, between the cerebellum and medulla, containing cerebrospinal fluid. |
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Term
| CEREBROSPINAL FLUID (CSF) |
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Definition
| A watery medium that is both formed and reabsorbed within the skull and serves primarily as a shock absorber. It surrounds the brain and spinal cord in the subarachnoid space and also fills the ventricular system and the hollow central canal of the spinal cord. |
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Term
| TWELVE PAIRS OF CRANIAL NERVES |
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Definition
| Traditionally represented by Roman numerals, these emerge from the ventral surface of the brain and brain stem and serve important sensory and motor functions, chiefly within the head. |
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Term
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Definition
| Largely made up of axons of nerve cells, some with cell bodies in the brain and others with cell bodies in the cord itself. |
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Term
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Definition
| Those that originate in the spinal cord and pass between pairs of vertebrae to supply the body with sensation and voluntary motor power. There are 31 sets of spinal nerves, one from each spinal segment. |
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Term
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Definition
| The sensory root of a spinal nerve. |
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Term
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Definition
| The motor root of a spinal nerve. |
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Term
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Definition
| A visible node or swelling on each dorsal root containing cell bodies of sensory nerves. |
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Term
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Definition
| The fused dorsal and ventral roots which pass forward around the body and give off branches to all external surfaces and internal structures, particularly muscles of the trunk and extremities. |
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Term
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Definition
| Send signals to voluntary muscles throughout the body. |
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Term
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Definition
| Carry impulses from sensory structures in the skin that respond to pain, pressure, light touch, hot and cold; from visceral sensors that respond to pressure stretching and pain; and from proprioceptive sensors in voluntary muscles that signal the brain as to their position, tension, and movement. |
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Term
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Definition
| A purely motor system concerned with automatic or involuntary activities or processes, such as heart rate and digestion. |
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Term
| SYMPATHETIC NERVOUS SYSTEM |
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Definition
| Concerned with the so-called fight or flight response mediated by epinephrine and norepinephrine. |
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Term
| PARASYMPATHETIC (CRANIOSACRAL) DIVISION |
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Definition
| Provide motor innervation to cranial, thoracic, abdominal, and pelvic viscera, generally of an opposite nature to sympathetic innervation. |
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Term
| ALTERED LEVEL OF CONSCIOUSNESS |
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Definition
| Varying from slight drowsiness or inattentiveness, to confusion and disorientation, to deep coma from which the subject cannot be aroused by any stimulus. |
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Term
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Definition
| Brief loss of attention and perception. |
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Term
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Definition
| Loss of memory, recent, remote, or total. |
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Term
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Definition
| Absence of cerebral hemispheres. |
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Term
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Definition
| Total loss of sensation on one or more parts of the body surface. |
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Term
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Definition
| Impairment of the ability to communicate through spoken or written language, or to understand spoken or written language, or both. |
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Term
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Definition
| Impairment of complex movements due to loss of proprioceptive impulses from the muscles of the trunk or limbs. |
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Term
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Definition
| Slow, writhing, involuntary movements of the face or limbs. |
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Term
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Definition
| Consists of dorsiflexion of the great toe and flaring of the other toes in response to stroking the sole of the foot toward the toes; an indication of disease or injury affecting a corticospinal tract. A normal reflex is downgoing, except in newborns and infants, in which the normal Babinski reflex is upgoing. |
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Term
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Definition
| Burning or stinging due to irritation or inflammation of nerves. |
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Term
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Definition
| Extension of the great toe elicited by tapping the ankle behind the lateral malleolus, a sign of disease or injury of a corticospinal tract. |
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Term
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Definition
| Rapid, jerky, purposeless involuntary movements of one or several muscle groups. |
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Term
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Definition
| Impaired alertness or unconsciousness; sometimes with psychic symptoms or automatisms. |
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Term
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Definition
| Also called muscle strength reflexes; occur in response to sudden stretching of a muscle, usually by tapping a tendon with a rubber-headed reflex hammer. Tendon reflexes are tested in several muscles of the upper and lower extremities, with comparison of the two sides. |
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Term
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Definition
| Deterioration of mental function. |
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Term
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Definition
| Loss of balance sense; tendency to fall without support. |
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Term
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Definition
| Absence of muscle tone and absence of reflexes. |
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Term
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Definition
| A seizure in which the entire cerebral cortex is involved. |
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Term
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Definition
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Term
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Definition
| Local or generalized, intermittent or constant; can result from infection, neoplasm, or hemorrhage within the cranium, obstruction to the flow of cerebrospinal fluid, trauma, or migraine. |
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Term
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Definition
| A more severe form of microcephaly, with very little cerebral cortex remaining. |
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Term
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Definition
| Partial loss of sensation on one or more parts of the body surface. |
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Term
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Definition
| Jerkiness and awkwardness in activities requiring smooth coordination of several muscles. |
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Term
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Definition
| Tremor occurring only during voluntary movement. |
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Term
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Definition
| Abnormally small, maldeveloped cerebral hemispheres, typically associated with mental and motor retardation. |
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Term
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Definition
| Repeated, shocklike, often violent contractions in one or more muscle groups. |
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Term
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Definition
| Complete loss of muscular function. |
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Term
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Definition
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Term
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Definition
| A sense of tingling or pricking ("pins and needles") on a part of the body surface. |
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Term
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Definition
| Seizure in which only part of one cerebral cortex is involved. |
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Term
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Definition
| Present only in neurological disorders, such as Babinski reflex or Chaddock reflex. |
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Term
| PETIT MAL SEIZURE (ABSENCE SEIZURE) |
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Definition
| Characterized by brief loss of attention and perception. |
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Term
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Definition
| Reproduction of pain or paresthesia in carpal tunnel syndrome when both wrists are flexed with the hands firmly pressing one another back-to-back for 60 seconds. |
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Term
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Definition
| One or more cysts or cavities in a cerebral hemisphere communicating with the ventricular system. There may be little or no neurologic impairment. |
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Term
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Definition
| After awakening from seizure, subject is drowsy and amnesic for a variable period. |
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Term
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Definition
| A muscular contraction occurring in response to a sensory stimulus. |
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Term
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Definition
| Tremor occurring only when the affected muscles are not being used for purposeful activity. |
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Term
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Definition
| Sudden, transitory impairment of central nervous system function, with or without loss of consciousness, and with or without local or generalized tonic and clonic contractions of voluntary muscles. |
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Term
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Definition
| No unconsciousness; local twitching or jerking; perception of flashing lights or other abnormal sensory phenomena. |
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Term
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Definition
| Sustained contraction, usually painful, of a muscle. |
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Term
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Definition
| Tight muscles with resistance to manipulation and hyperactive reflexes. |
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Term
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Definition
| A failure of closure of one or more vertebrae in the posterior midline, which may be associated with bulging of the meninges (meningocele), or of spinal cord and meninges (meningomyelocele). |
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Term
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Definition
| Series of grand mal seizures without waking intervals. |
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Term
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Definition
| Muscle contractions in response to stroking the skin; those of the abdominal wall are tested as part of a complete neurologic exam. |
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Term
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Definition
| Sudden loss of consciousness, usually transitory, due to circulatory or neurologic abnormality, including central nervous system intoxication or injury, but frequently the result of strong emotion in the absence of organic disease. |
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Term
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Definition
| A rapid involuntary muscle twitch, typically recurrent and stereotyped, affecting one or several body areas. |
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Term
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Definition
| Shocklike pain when the volar aspect of the wrist is tapped; indicative of carpal tunnel syndrome. |
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Term
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Definition
| In the tonic phase the victim becomes rigid, often cries out, loses consciousness, falls, stops breathing. In the clonic phase there is generalized muscular jerking; may bite tongue or lips, may be incontinent of urine or stool. |
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Term
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Definition
| Shaking of parts of the body supplied by voluntary muscles, principally the arms, forearms, and hands. |
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Term
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Definition
| A subjective sense of spinning. Dysequilibrium and vertigo sometimes occur together, and both are indiscriminately referred to as dizziness by the laity. |
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Term
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Definition
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Term
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Definition
| Seizure; epileptic seizure. |
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Term
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Definition
| Hypesthesia, anesthesia, or paresthesia. |
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Term
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Definition
| Sense of tingling or prickling. |
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Term
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Definition
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Term
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Definition
| Cerebrovascular accident (CVA) |
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Term
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Definition
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Term
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Definition
| May be used to show cranial vasculature with injected contrast medium.In digital subtraction angiography, x-ray images of the head with and without contrast medium are processed by a computer, which deletes all shadows common to both films, leaving only the vascular system visible. |
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Term
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Definition
| An examination based on the distribution of a radioactive isotope injected systemically in brain tissue. |
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Term
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Definition
| Surgical incision into the cranium, which necessitates drilling or sawing through the bone of the skull. |
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Term
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Definition
| Surgical removal of part of the bone of the skull. |
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Term
| ELECTROENCEPHALOGRAPHY (EEG) |
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Definition
| Measurement and recording of electrical activity from several sites simultaneously. Electrodes are attached with fine needles to standard sites on the scalp, and the record is made on a strip of moving paper. |
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Term
| ELECTROPHYSIOLOGIC STUDIES |
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Definition
| Measurement of electrical activity in nerves and muscles. Electromyography (EMG) involves insertion of fine needle electrodes into voluntary muscles. Nerve conduction velocity (NCV) is measured by timing the passage of nerve impulses between a stimulating and a recording electrode, which are a precisely measured distance apart. |
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Term
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Definition
| The patient extends the arms outward laterally, closes the eyes, and tries to touch the finger to the nose. Test coordination. |
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Term
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Definition
| With the patient standing straight, the heel of one foot is placed against the shin of the opposite leg. Tests coordination. |
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Term
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Definition
| Assessing the subject's ability to recognize hot and cold (via test tubes of hot and cold water) on various parts of the body surface. Sensory examination. |
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Term
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Definition
| CT scan (with or without intravenous injection of contrast medium), MRI, and standard x-ray views of the skull. |
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Term
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Definition
| Assessing the subject's ability to recognize wisps of cotton drawn across the skin on various parts of the body surface. Sensory examination. |
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Term
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Definition
| Withdrawal of a specimen of cerebrospinal fluid from the subarachnoid space by inserting a needle between two vertebrae (usually L4 and L5) at the lower end of the spinal cord. |
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Term
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Definition
| A graduated glass tube used to measure the pressure of the fluid at the beginning of the procedure and the end (opening and closing pressure). |
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Term
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Definition
| Name given to the yellowish hue of CSF fluid. |
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Term
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Definition
| Visualization of the spinal canal by x-ray with contrast medium introduced into the subarachnoid space by lumbar puncture. |
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Term
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Definition
| Assessing the subject's ability to recognize a prick from a sterile needle on various parts of the body surface. Sensory examination. |
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Term
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Definition
| Tested by having the subject report whether a toe or finger is moved up or down by the examiner. |
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Term
| RAPIDLY ALTERNATING MOVEMENTS TEST |
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Definition
| A test for coordination, this test has the patient perform rapid alternating movements of the hands or feet. |
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Term
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Definition
| Has the subject stand with feet together and eyes open, then eyes closed, to assess position sense in the trunk and legs. |
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Term
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Definition
| Test of the patient's ability to recognize an object by handling it. |
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Term
| SURGICAL DRAINAGE OF AN ABSCESS |
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Definition
| Usually preceded by antibiotic therapy, a craniotomy is performed and the abscess drained. |
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Term
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Definition
| Tests the subject's ability to walk with one foot in front of the other in a straight line. A coordination test often used by police officers to assess drivers for substance abuse. |
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Term
| TWO-POINT DISCRIMINATION TEST |
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Definition
| Test of a patient's ability to distinguish two points close together on the skin. |
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Term
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Definition
| Test of the patient's ability to sense the vibration of a tuning fork when the stem is placed on a bone near the surface, such as the elbow or shin. |
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Term
| CSF (CEREBROSPINAL FLUID) |
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Definition
| The fluid medium of the CNS (brain and spinal cord), which can be sampled by lumbar puncture (spinal tap) for chemical testing, cell counts, and culture. |
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