Chapter 24

Question 1

Central nervous system (CNS)

Answer 1

controls and coordinates everything
includes the brain and spinal cord

Question 2

peripheral nervous system (PNS)

Answer 2

collects and transmits data from the body
includes spinal nerves and neurons

Question 3

sensory neurons

Answer 3

send signals from the sensors in the periphery to the CNS

Question 4

motor neurons

Answer 4

send signals from the CNS to the periphery

Question 5

meningitis

Answer 5

inflammation of the meninges, causes severe headaches, fever and confusion

Question 6

encephalitis

Answer 6

inflammation of the brain, causes problems with cognitive, sensory, and motor functions

Question 7

primary encephalitis

Answer 7

microbe directly infects the brain ex rabies

Question 8

secondary encephalitis

Answer 8

microbe spreads from an infection of the meninges to the brain tissue

Question 9

myelitis

Answer 9

inflammation of the spinal cord

Question 10

radiculitis

Answer 10

inflammation of the spinal nerve root, where the nerve exits the vertebra

Question 11

meningoencephalitis

Answer 11

simultaneous inflammation of the meninges and the brain

Question 12

paresthesia

Answer 12

numbness, tingling, pinprick sensation (a symptom of encephalitis)

Question 13

hyperesthesia

Answer 13

extreme sensitivity (a symptom of encephalitis)

Question 14

areflexia

Answer 14

absence of reflexes, nonspecific symptoms (a symptom of encephalitis)

Question 15

viral infections

Answer 15

Most common pathogen of the CNS
Treatment is supportive
Aimed at reducing inflammation
Generally mild

Question 16

bacterial, fungal, and parasitic infections

Answer 16

Less common but often more severe
Antibiotics, antifungals, or other drugs are often used to limit pathogen growth.
Vaccination is best for prevention but is not available for every disease.

Question 17

rabies

Answer 17

RNA virus, bullet-shaped
Zoonotic disease
Neurotropic
Prefers to replicate in nerves
Three forms
Encephalitic (80%)-aggressive
Paralytic-weakness in limbs
Atypical-neuropathic pain (from bat bites)
Treatments
Immunoglobulin
Rabies vaccine

Question 18

mosquito-borne encephalitis

Answer 18

eastern equine encephalitis (EEE)
west nile encephalitis (WNV)

Question 19

eastern equine encephalitis (EEE)

Answer 19

Transmitted from bird to bird by mosquitoes
Can also be passed to horses and humans
Rare, but has a high rate of fatality (35%)

Question 20

west nile virus (WNV)

Answer 20

Transmitted in bird populations by mosquitoes
Most infected patients do not develop disease
Usually causes a flu-like illness, but some develop encephalitis

Question 21

Viral meningitis

Answer 21

Normally not as severe as bacterial meningitis
Called aseptic meningitis as CSF fluid is clear

Question 22

Lymphocytic choriomeningitis virus (LCMV)

Answer 22

RNA virus
Causes meningitis, encephalitis, or both
Household mice are a reservoir.
Causes elevation of lymphocytes in the CSF

Question 23

poliomyelitis

Answer 23

Very contagious
Enterovirus
Transmitted by fecal-oral route or directly from person to person via saliva-can reach the CNS
Most infected patients remain asymptomatic
Only 1% of symptomatic patients develop paralysis
Vaccine efforts have come close to eradicating the disease.
Salk vaccine-inactivated virus
Sabin vaccine-live, attenuated
No longer used-can revert via mutation to virulent form

Question 24

bacterial meningitis

Answer 24

Symptoms include
Sudden onset of severe headache
Fever
Stiffness of the neck (nuchal rigidity)
Three main etiologies
N. meningitidis: young adults
H. influenzae type B: young children
S. pneumonia: infants, children, and elderly
Vaccination against these three major bacterial pathogens has reduced rates of this deadly disease.

Question 25

meningococcal meningitis

Answer 25

Neisseria meningitidis
Gram-negative diplococcus
Spreads directly from person-to-person contact or contact with contaminated fomites
Uses specialized pili to adhere to and invade epithelial cells, then enters blood stream
Produces an endotoxin that causes a purpuric rash

Question 26

listeriosis

Answer 26

Listeria monocytogenes
Foodborne pathogen
Causes diarrhea and fever
Complications, including meningitis and brain abscess, occur in pregnant women and immunocompromised patients.
Infection during pregnancy leads to fetal infection and death.

Question 27

neonatal meningitis

Answer 27

Occurs in newborns less than a week old
Bacteria found in the mother’s vaginal secretions can be a source of infection.
Common sources
Escherichia coli
Group B streptococcus

Question 28

botulism

Answer 28

Obligate anaerobe
Foodborne pathogen
Associated with vegetables and honey
Due to spores being in the soil
Botulinum toxin can cause paralysis by binding to motor neurons and blocking acetylcholine release.

Question 29

tetanus

Answer 29

Clostridium tetani
Causes intense muscle contraction
Tetanospasmin toxin is similar to botulinum toxin, but in contrast to botulinum toxin, causes excessive nerve signaling to muscles to contract.