Unit 12 Nervous System Flashcards
0
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Structure of CNS
A
- Brain-within the skull
- spinal cord
1
Q
Functions of the nervous system
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- Receives information from the body
- processes & interprets information
- produces a response
2
Q
Normal circulation of CFS and structural components required
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CSF circulation starts from:
2 lateral ventricles through interventricular formamina, into 3rd ventricle, through cerebral aqueduct, into 4th ventricle through lateral and medial apertures into subarachnoid space of brain
3
Q
Brain trauma: concussion
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Loss of cerebral control following injury
Immediate and temporary disturbance of brain function, disruption of normal electrical activity
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Concussions result in
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–blood leaking into the brain
–injection of spinal fluid into the brain, molecular (chemical) disturbance
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Symptoms of concussions
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–drowsiness, loss of coordination,
-slow pulse, convulsions, projectile vomiting, stupor, comatose
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Contusion (bruise)
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crushing (compression) of the brain
•leads to hemorrhage
•often accompanied by swelling
•caused by fracture or trauma to the skull
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Laceration
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cutting wound that penetrates the skull
-results in hemorrhage
8
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extradural hemorrhage
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- due to fracture or trauma to the head
- blood collects & proceeds down to brain
- if unrelieved, death can occur in days or weeks
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Q
subdural hemorrhage
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more severe fracture or injury
- more rapid bleeding
- if unrelieved, death can occur w/in a few days
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subarachnoid hemorrhage
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most severe, due to laceration
- very rapid bleeding into the brain
- death can occur w/in hours
11
Q
meningitis
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inflammation of the meninges
- caused by microorganisms that spread into blood & CSF
- may affect any age group
12
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bacterial meningitis
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(neisseria meningitides)
- life threatening
- may cause epidemic meningitis
- spread by respiratory secreations
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other causes of bacterial meningitis include
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viruses, fungi, protozoans & cancers
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fungal meningitis
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common in people w/ impaired immune systems (AIDS)
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symptoms of meningitis
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headaches, stiff neck, fever, photophobia, vomiting
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Cerebrovascular Accident (CVA)
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- Apoplexy/stroke
- sudden death of some brain cells due to lack of oxygen caused by blockage or rupture of an artery in the brain
- effect depends on size of the hemorrhage
- 3rd leading cause of death
17
Q
Predisposing factors of Cerebrovascular Accident (CVA)
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- arteriosclerosis
- high blood pressure
- thrombus or embolus in cerebral blood vessel,
- aneurysm
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most common symptom of CVA
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eakness or paralysis of one side of the body with partial or complete loss of voluntary movement or sensation in a leg or arm
19
Q
Transient Ischemic Attack (TIA)
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temporary lack of circulation to a part of the brain
20
Q
temporary symptoms of Transient Ischemic Attack
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- loss of sensation, movement, speech, mental function or vision
- signs & symptoms generally disappear completely within 24 hours (after resumption of blood-flow)
21
Q
Hydrocephalus
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Excessive accumulation of CSF in the ventricles of the brain
22
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hydrocephalus is usually due to
A
•obstruction of flow of CSF out of the brain
–congenital defect
–in newborns: toxoplasmosis (parasite in cat liter)
–infection (encephalitis), brain tumor
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Q
hydrocephalus can result in
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- brain damage, mental changes
- bulging eyes, tight scalp, prominent head vein
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Encephalitis
inflammation of brain tissue
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encephalitis is caused by
- bacteria (staph, strep)
- viruses
- complication of measles or chicken pox
- infections usually spread from upper respiratory tract, sinuses, ears, or eyes
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Symptoms of Encephalitis
* swelling of the brain
* fever, headache, body aches, skin rash & swollen lymph nodes
* severe infections - high fever, stiff neck, stupor (sleepiness), disorientation, coma, tremors, occasional convulsions, paralysis, & rarely death
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death rate for encephalitis
3% to 15% (higher in elderly than in younger)
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Neurosyphilis
late stages of syphilis often affect the brain and spinal cord
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damage to the brain caused by neurosyphilis
–include general paresis (incomplete paralysis)
| –can result in dementia, deafness, blindness, paralysis, insanity
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damage to the spinal cord due to neurosyphilis
Tabes Dorsalis = slowly progressive degeneration of the spinal cord that occurs in late phase of syphilis, results in locomotive ataxia (wobbliness)
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Cerebral Abscess
mass of immune cells, pus, and other material draining into deeper brain tissue
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cerebral abscesses are usually from
bacterial or fungal infection
| –bacteria can get to the brain from injury, respiratory tract, ear or eye infection
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Cerebral Abscess results in
•results in necrosis of healthy brain tissue
| –encephalomalacia (brain softening)
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Encephalomyelitis
acute inflammation of the brain (encephalo-) & spinal cord (myelo-)
•can be caused by viruses which infect the nervous system
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acute disseminated encephalomyelitis
–occurs most commonly after acute viral infection such as measles (rubeola) autoimmune attack on nervous system
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Poliomyelitis (Polio=Infantile Paralysis)
inflammation of the spinal cord
•Highly infectious, mainly affects children under 5
•Spread through oral or fecal-oral route
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Poliomyelitis results in
–Fever, headache, sore throat, abdominal pain
–Stiffness of neck, trunk, extremities
–Atrophy of group of muscle
–Paralysis in hours (e.g., respiratory, GI tract or leg)
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Rabies
acute viral infection of the central nervous system of warm-blooded animals (wolves, cats, dogs)
•transmitted by bite of rabid animal (rabies=madness, rage, fury)
•if left untreated,100% fatal in animals
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Rabies results in
–hydrophobia (fear of water, attempts to drink water trigger laryngeal spasm)
–increase in saliva production
–abnormal behavior
–paralysis--> respiratory failure-->coma-->death
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Neuritis
inflammation of nerve or nerves
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etiology of neuritis
–injury – compression, contusion
–infection (tetanus, tuberculosis), inflammation
–chemical poisoning (arsenic, lead), medication
–neoplasm or stress
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symptoms of neuritis
- headaches
- hyperesthesia (hypersensitivity)
- paresthesia (numbness, tingling)
- dysesthesia (painful sensation)
- muscular atrophy of part supplied by affected nerve,
- paralysis
- lack of reflexes
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Tetanus
acute, infectious, life-threatening bacterial disease that affects the nervous system,
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Tetanus is caused by
toxin produced by Clostridium tetani-->toxin attaches to motor neurons
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Tetanus results in
painful muscle contractions, particularly of jaw (lockjaw ) and neck muscles
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Tetanus is found in
animal feces, spores in soil
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Symptoms of Tetanus
* painful, uncontrolled contractions of skeletal muscles
* high fever
* tachycardia (faster heartbeat)
* dysphagia (difficulty swallowing)
* intense pain
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Epiliepsy
chronic neurogenic disease marked by sudden alterations in consciousness & convulsions
•a temporary lack of oxygen to vital brain centers
•recurrent seizures of unknown origin
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2 types of epilepsy
Petit mal seizure = small
•Loss of consciousness, usually for few seconds
•No memory of the seizure, no complications
Grand mal seizure = large
•Loss of consciousness, muscle rigidity, spasms of face, neck, arms, legs, person will thrash about
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epilepsy may result in
–cyanosis, breathing difficulty, tongue may be bitten, excess salivation, bloody froth or saliva
•Generally lasts for a few minutes
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Predisposing factors of epilepsy
* Congenital abnormality of blood vessels in the brain
| * Some disorders which block blood flow to the brain
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CNS: Degenerative Diseases
* Alzheimer’s disease
* Amyotrophic lateral sclerosis
* Parkinson’s syndrome
* Multiple sclerosis
* Creutzfeldt - Jakob Disease
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Alzheimer's Disease
progressive & fatal brain disease,
•named for German physician Alois Alzheimer
•most common type of dementia
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alzheimer's disease is due to
formation of protein plaques, or tangles of nerve fibers in the brain that interfere with communication between nerve cells in the brain
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Symptoms of Alzheimer's Disease
* amnesia, impaired recognition, forgetfulness
* emotional upsets, confusion, mood changes,
* inability to concentrate, inability to complete simple tasks
* irritability, agitation, restlessness , depression, hostility
* motor disturbances, muscle rigidity, paralysis, apraxia (skilled movements)
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Amyotrophic Lateral Sclerosis
Lou Gehrig’s disease
| •destroys both: upper & lower motor neurons (brain & spinal cord)
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Symptoms of ALS
•cramps, muscle weakness, uncontrollable twitching
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Parkinson's Syndrome
degenerative disorder of the central nervous system basal ganglia (nuclei) causing faulty nerve signal transmission
•insufficient dopamine
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Causes of Parkinson's Syndrome
* environmental toxins, no hereditary basis
* trauma (often affect boxers),
* tumors, prior infections, drugs, atherosclerosis (more common)
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Symptoms of Parkinson's Syndrome
* “tremors at rest”, rigidity of muscles, weakness of muscles, a forward lean
* slurred speech
* digestive and urinary difficulty
* hypotension (low blood pressure)
* In late stages: depression & dementia
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Multiple Sclerosis
degeneration of the brain and spinal cord
| •autoimmune disease - body attacks its own myelin
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Multiple Sclerosis is characterized by
remissions and relapses and by the presence of sclerotic (hardening ) patches of demyelination
•softening of the spinal cord
•ages 25-40
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Symptoms of Multiple Sclerosis
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•Loss of coordination (1st symptom)
•Optic disturbances
•Tremors
•disturbance in neural pathways
–local anesthesia and paralysis
•Respiratory problems
•Loss of bowel and bladder control
•Paralysis to the limbs
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Creutzfeldt-Jakob Disease
degenerative neurological disorder of the brain
- very rare
- incurable
- rapid development (6-12 months)
- possibly from eating infected beef
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cause of Creutzfeldt-Jakob Disease
protein called a prion that folds abnormally, which affects its function
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Symptoms of Creutzfeldt-Jakob Disease
–personality changes, hallucinations,
–muscle twitching & stiffness
–lack of coordination
–speech impairment
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CNS: Congenital Disorders
Cerebral palsy
Microcephaly* - small brain
•occurs with Down's Syndrome
Anencephaly* - no brain
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Cerebral Palsy
motor disturbance present at birth, usually due to a congenital birth defect or birth trauma
-non-progressive, little or no mental damage
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symptoms of cerebral palsy
•limited motor skills, speech difficulties, learning disabilities
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CNS: Genetic Disorders
caused by gene mutations – permanent changes in the genetic material
–due to radiation, chemicals, viruses
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autosomal dominant disorders
- Neurofibromatosis
| - Huntington's Disease
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Neurofibromatosis
disorder of a particular tumor suppressor gene
–peripheral nerve benign tumor
–arise from fibrous coverings of nerves
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Huntington's Disease
neurological disorder that leads to progressive degeneration of brain cells-->loss of psychomotor control of body
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autosomal recessive disorders
Tay Sachs disease=lack of enzyme (hexosaminidase A) that helps break down a lipid found in nervous tissue called ganglioside
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Tay Sachs Disease is most common in
certain Eastern European Jewish population
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Gliomas
tumors originating in neuroglia of the brain or spinal cord
•most common type of brain tumor
•categorized by location & type of cells that originated the tumor
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Astrocytomas
astrocytes, in brain or spinal cord
–most common type of childhood brain tumor
–in cerebellum
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Meningioma
* tumor of meninges (dura)
* slow growing, most common in 40 & 50 year-old people
* in cerebral hemispheres, under the skull
* usually are separate from the brain & can be removed entirely during surgery
* Can recur & certain types can be malignant
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Retinoblastoma
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malignant tumor of one or both eyes
•retinal cells
•Develops during infancy or early childhood
•Usually diagnosed by two years of age
•Probably hereditary
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