ch 17 objectives

Question 1

Describe the important anatomical features of the nervous system

Answer 1

The nervous system comprises the brain, spinal cord, and peripheral nerves. Its key anatomical features include neurons, which transmit electrical signals; glial cells, which support and protect neurons; and synapses, the junctions where neurons communicate.

Question 2

List the natural defenses present in the nervous system

Answer 2

the blood-brain barrier, which limits the passage of harmful substances into the brain; microglia, immune cells that patrol the central nervous system and remove pathogens; and astrocytes, which help regulate the extracellular environment and support neuronal function.

Question 3

immune privilege

Answer 3

refers to the specialized immune protection of certain tissues or organs, such as the brain and the eye, which have restricted immune responses to prevent damage from inflammation.

Question 4

Discuss the current state of knowledge of the normal biota of the nervous system

Answer 4

The nervous system lacks an indigenous microbiota.

Question 5

Describe the type of sample collected to diagnose a CNS infection

Answer 5

cerebrospinal fluid through spinal tap

Question 6

neisseria meningitis (acute)

Answer 6

modes of transmission: droplet contact
virulence factors: capsule, endotoxin
diagnostic techniques: gram stain, oxidase, rapid antigenic tests
prevention and treatment: conjugated vaccine ciprofloxacin, rifampin to prevent
penicillin to treat

Question 7

streptococcus pneumoniae (acute)

Answer 7

modes of transmission: droplet contact
virulence factors: capsule, apoptosis, hemolysin and hydrogen peroxide production
diagnostic techniques: gram stain, culture on csf
prevention and treatment: two vaccines: PCV13 and PPSV23 penicillin to prevent

Question 8

haemo influenzae

Answer 8

modes of transmission: droplet contact
virulence factors: capsule
diagnostic techniques: culture on chocolate agar
prevention and treatment: Hib vaccine treat with ceftriaxone

Question 9

listeriosis (acute)

Answer 9

modes of transmission: listeria monocytogenes
virulence factors: vehicle (consumption of contaminated foods)
diagnostic techniques: culture on blood agar
prevention and treatment

Question 10

meningitidis

Answer 10

inflammation of the meninges caused by bacterial or viral infection

Question 11

blood brain barrier

Answer 11

barrier that controls what can enter CNS

Question 12

2 causes of bacterial intoxication

Answer 12

clostridium tetani and clostridium botulinum

Question 13

diseases caused by clostridium botulinum, tetanus, botulism

Answer 13

botulinum: ingestion of food
tetanus: caused by opened wound contact
botulism:ingestion of food (typically canned)

Question 14

GBS (neonatal)

Answer 14

causative agent: group b streptococci
transmission: in utero or through birth canal
prevention and treatment: ampicillin or penicillin

Question 15

E.coli (neonatal)

Answer 15

causative agent: e.coli
transmission: most often in premature, birth canal
prevention and treatment: ceftazidime or cefepime intravenously

Question 16

listerioses

Answer 16

causative agent: listeria monocytogenes
transmission: foodborn from contaminated lunch meat and transferred to babies (vertical)
prevention and treatment: avoid foods

Question 17

cronobacter sakazakii

Answer 17

causative agent: cronobacter sakazakii
transmission: via contaminated powdered infant formula (vehicle)
prevention and treatment: use ready to feed and concentrated liquid formulas

Question 18

infant vs wound vs foodborne botulism

Answer 18

infant: occurs when infant is fed honey
wound: when wound is infected
foodborne: contaminated food is consumed

Question 19

arbovirus

Answer 19

causative agent: arbovirus
transmission: vector (through bites)
virulence factor: attachment,fusion
prevention and treatment: insect control

Question 20

west nile

Answer 20

causative agent
transmission: vector (mosquito bites)
virulence factor: envelope allows it to pass undetected
prevention and treatment: no vaccine or treatment

Question 21

rabies

Answer 21

causative agent: rabies virus
transmission: parenteral (bite trauma) or droplet contact
virulence factor: envelope glycoprotein
prevention and treatment: inactivated vaccine, passive and active immunization

Question 22

zika

Answer 22

causative agent: zika virus
transmission: vertical, vector borne, sexual contact, likely through blood transfusions
virulence factor
prevention and treatment: supportive

Question 23

polio

Answer 23

causative agent: poliovirus
transmission: fecal-oral or vehicle
virulence factor: attachment mechanisms
prevention and treatment: live attenuated or inactivated vaccine, no treatment

Question 24

hsv

Answer 24

causative agent: human herpes virus 1 and 2
transmission: vertical or reactivation of herpes virus
virulence factor: n/a
prevention and treatment: maternal screening and treat with acyclovir

Question 25

2 fungal causes of meningitis

Answer 25

cryptococcis (yeast) and coccidiomycosis (mold)

Question 26

amoebic causes of meningoencephalitis

Answer 26

naegleria fowleriia and acanthaomeba

Question 27

naegleria fowleriia

Answer 27

causative agent: naegleria fowleriia
transmission: vehicle (swimming in water)
virulence factor: invasiveness
prevention and treatment: limit freshwater entry in nasal passages

Question 28

acanthamoeba

Answer 28

causative agent: acanthamoeba
transmission: direct contact
virulence factor: invasivness
prevention and treatment: surgical excision of granulomas

Question 29

encephalitis

Answer 29

inflammation of the brain

Question 30

acute vs subacute encephalitis

Answer 30

acute: caused by viruses borne by insects (west nile)
subacute: longer to show up

Question 31

transmissible spongiform encephalopathies

Answer 31

causative agent proteinaceous infectious particles
transmission: vehicle (consumption of contaminated meat)
treatment/prevention: no cure, avoid contaminated meat and animals