Chapter 26

Question 1

CNS

Answer 1

brain and spinal cord

Question 2

PNS

Answer 2

peripheral nerves

Question 3

Nervous System

Answer 3

Cells are called neurons, no normal flora

Question 4

Natural Defenses of the Nervous System

Answer 4

• Skull and vertebrae
• Microglial cells and macrophages
• Restricted entry into brain (blood-brain barrier) for: microorganisms , medications (including most antibiotics), immune system

Question 5

Both Bacteria and viruses and parasites can cause

Answer 5

Meningitis and encephalitis

Question 6

Meningitis

Answer 6

inflammation of the meninges =
membranes surrounding the brain and spinal cord

Question 7

Encephalitis

Answer 7

inflammation of the brain

Question 8

Nervous System Diseases (Viruses)

Answer 8

Rabies and Poliomyelitis

Question 9

Nervous System Diseases (Neurotoxins)

Answer 9

Tetanus

Question 10

Bacterial Meningitis (Haemophilus influenzae type b)

Answer 10

Infants, newborn (also, E. coli, Streptococcus agalactiae = Group B Strep)

Question 11

Bacterial Meningitis (Streptococcus pneumoniae)

Answer 11

Children 1 month - 4 years, Elderly

Question 12

Bacterial Meningitis (Neisseria meningitidis)

Answer 12

College students

Question 13

Streptococcal Meningitis (Caused by Streptococcus pneumoniae)

Answer 13

• Gram + diplococci
• Virulent strains are encapsulated
• Children age 1 month – 4
years
• Elderly

Question 14

Meningococcal Meningitis in College Students (Neisseria meningitidis)

Answer 14

Enters through nasal cavity (droplets)
Incidence = 2,500 Americans/year 10-15% die, up to 20% long-term disabilities

Question 15

Subunit vaccine

Answer 15

induces opsonizing antibody to
capsule

Question 16

Naegleria Meningoencephalitis (a rare infection caused by Naegleria fowleri)

Answer 16

Small free-living amoeba found in fresh water, can be normal flora. Protozoan feeds on bacteria but if introduced into
the CNS can feed on human tissue.

Question 17

Acquired from hot tubs, warm ponds and ground water at high temperature, initially infects the nasal mucosa

Answer 17

Naegleria meningoencephalitis

Question 18

Naegleria meningoencephalitis Symptoms

Answer 18

•Abrupt onset of symptoms 3 to 10 days after exposure to water
•Severe headache, fever, stiff neck, dementia and coma
•Children and young adults

Question 19

Naegleria meningoencephalitis (TERRIFYING FACTS?)

Answer 19

•Destroys brain and spinal tissue
•Death occurs within 10 days of the onset of clinical signs
•No treatment
•Chlorine kills the organism in spas and pools
•Mortality rate of >95%

Question 20

Toxoplasmosis (caused by Toxoplasma gondii)

Answer 20

• Flagellated protozoan parasite
• Infects over 200 species of birds and animals
• Primary reservoir is cats
• Infection usually handled by immune system

Question 21

Acquired from contaminated meat or
ingestion of oocysts in cat feces

Answer 21

Toxoplasmosis

Question 22

Toxoplasmosis High Risk Factors

Answer 22

-Causes serious disease in developing fetus
• Liver damage
• Brain abnormalities
• Blindness
-Serious disease in people with AIDS

Question 23

Toxoplasmosis Prevention

Answer 23

no raw meat, no contact with cat litter box

Question 24

Hansen’s Disease (Leprosy)

Answer 24

•Disease of skin and nerves
•Change of pigmentation, loss of sensation
•Slow progressing
•Transmits poorly
•Droplet or skin contact?

Question 25

Mycobacterium leprae (Hansen’s Disease)

Answer 25

•Acid fast bacterium •Slow growth •Strict parasite •Multiplies in macrophages •Prefers cool areas of body •Long course, drug cocktail

Question 26

Rabies

Answer 26

Viral infection from bite of a “furious” rabid animal (Animal rabies: Wandering, aggression, biting, salivating)

Question 27

Rabies Infection

Answer 27

1. Bite then virus grows in muscle 2. Virus enters sensory nerve ending 3. Virus travels to cord, brain 4. Virus grows in brain, changes behavior 5. Virus travels to salivary gland and is secreted

Question 28

A fatal zoonotic disease with a variable latent period

Answer 28

Rabies

Question 29

Human “dumb” rabies

Answer 29

fever, confusion, anxiety, encephalitis, death

Question 30

Diagnosis of Rabies

Answer 30

-Performed via a Post-mortem autopsy on animals -Observing neuronal brain cells with intracytoplasmic inclusions (Negri bodies) -Identification of Rabies Strain -(Bat, Skunk, etc….)

Question 31

Paralytic Poliomyelitis

Answer 31

Neurotropic viral infection acquired by ingestion (Paralytic spinal cord infection)

Question 32

Paralytic Poliomyelitis vaccine

Answer 32

-Effective vaccine (PV-1,2,3) -Unvaccinated children are at risk in parts of the world like India, Africa

Question 33

The unique stages of infection and pathogenesis of poliomyelitis

Answer 33

Poliovirus, an “Enterovirus” has an icosahedral capsid shell that protects it from digestion.

Question 34

Clostridium tetani

Answer 34

soil organism and the causative agent of tetanus (have a unique tennis racket morphology)

Question 35

The Events in Tetanus

Answer 35

Bacterial invasion, release of bacterial toxin, and symptoms: Rigid Paralysis