Nervous Flashcards
Peripheral Nervous System (PNS)
The PNS includes the 12 pairs of cranial nerves extending from the brain and the 31 pairs of peripheral spinal nerves extending outward from the spinal cord. The function of the PNS is to transmit nerve signals to and from the central nervous system.
Nerve; Tract
A nerve is one or more bundles of neurons that connect the brain and the spinal cord with other parts of the body.
A tract is a bundle or group of nerve fibers located within the brain or spinal cord.
Ascending nerve tracts - nerve impulses toward the brain
Descending nerve tracts - nerve impulses away from the brain
Plexus
A network of intersecting spinal nerves.
Also describes a network of intersecting blood or lymphatic vessels.
White matter; Gray matter
White matter is the portion of nerve fibers that is myelinated.
Gray matter is unmyelinated nerve tissue. The lack of myelin sheath reveals a brownish-gray color of the cerebral cortex, cerebellum, and spinal cord core.
The Meninges
Dura mater - thick, tough, outermost membrane
Arachnoid membrane - resembles a spider web, the second layer located between the dura mater and the pia mater
Pia mater - located nearest to the brain and spinal cord. It consists of delicate connective tissue that contains a rich supply of blood vessels.
Thalamus
Located below the cerebrum, above the hypothalamus. Relays sensory stimuli from the spinal cord and midbrain to the cerebral cortex. The thalamus suppresses some stimuli and magnifies others.
Brainstem
Located in the base of the brain and forms the connection between the brain and spinal cord. It consists of the midbrain, pons, and medulla oblongata. The brainstem controls the functions necessary for survival (breathing digestion, heart rate, and blood pressure) and for arousal (being awake and alert).
Psychiatrist
A physician who specializes in diagnosing and treating chemical dependencies, emotional problems, and mental illness. A psychiatrist can prescribe medications.
Encephalocele
Craniocele, a congenital herniation of brain tissue through a gap in the skull.
Reye’s syndrome
A serious and potentially deadly disorder in children that is characterized by vomiting and confusion. This syndrome sometimes follows a viral illness in which the child was treated with aspirin.
Amyotrophic lateral sclerosis
ALS, or Lou Gehrig’s disease, is a rapidly progressive neurological disease that attacks the nerve cells responsible for controlling voluntary muscles. Patients affect with ALS become progressively weaker until they are completely paralyzed and die.
Cranial hematoma
A collection of blood trapped in the tissues of the brain. Named for their location e.g., epidural or subdural.
Stupor
An unresponsive state from which a person can be aroused only briefly despite vigorous, repeated attempts.
Syncope
Fainting, the brief loss of consciousness caused by the decreased flow of blood to the brain.
Delirium
An acute condition of confusion, disorientation, disordered thinking and memory, agitation, and hallucinations.
Intracranial pressure
The amount of pressure inside the skull. Elevated ICP can be due to a tumor, an injury, or improper drainage of CSF. Elevated ICP can potentially restrict the flow of blood to the brain, depriving it of oxygen.
Somnambulism
Sleepwalking, or noctambulism, the condition of walking or performing some other activity without awakening.
Myelosis
A tumor of the spinal cord.
Myelosis also means an abnormal proliferation of bone marrow tissue.
Radiculitis
Pinched nerve, an inflammation of the root of a spinal nerve that causes pain and numbness radiating down the affected limb.
Tonic-clonic seizure; Absence seizure
A tonic-clonic, or grand mal seizure, involves the entire body. In the tonic phase of the seizure, the body becomes rigid, and in the clinic phase, there is uncontrolled jerking.
An absence, or petit mal seizure, is a brief disturbance in brain function in which there is a loss of awareness often described as a staring episode.
Neuroleptic
An antipsychotic drug that is administered to treat symptoms of severe disorders of thinking and mood that are associated with neurological and psychiatric illnesses such as schizophrenia, mania, and delusional disorders.
Hypnotic
A medication that depresses the central nervous system and usually produces sleep.
Sedative
A medication that depresses the central nervous system to produce calm and diminished responsiveness without producing sleep.
