ch 17 objectives Flashcards
Describe the important anatomical features of the nervous system
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.
List the natural defenses present in the nervous system
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.
immune privilege
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.
Discuss the current state of knowledge of the normal biota of the nervous system
The nervous system lacks an indigenous microbiota.
Describe the type of sample collected to diagnose a CNS infection
cerebrospinal fluid through spinal tap
neisseria meningitis (acute)
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
streptococcus pneumoniae (acute)
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
haemo influenzae
modes of transmission: droplet contact
virulence factors: capsule
diagnostic techniques: culture on chocolate agar
prevention and treatment: Hib vaccine treat with ceftriaxone
listeriosis (acute)
modes of transmission: listeria monocytogenes
virulence factors: vehicle (consumption of contaminated foods)
diagnostic techniques: culture on blood agar
prevention and treatment
meningitidis
inflammation of the meninges caused by bacterial or viral infection
blood brain barrier
barrier that controls what can enter CNS
2 causes of bacterial intoxication
clostridium tetani and clostridium botulinum
diseases caused by clostridium botulinum, tetanus, botulism
botulinum: ingestion of food
tetanus: caused by opened wound contact
botulism:ingestion of food (typically canned)
GBS (neonatal)
causative agent: group b streptococci
transmission: in utero or through birth canal
prevention and treatment: ampicillin or penicillin
E.coli (neonatal)
causative agent: e.coli
transmission: most often in premature, birth canal
prevention and treatment: ceftazidime or cefepime intravenously
listerioses
causative agent: listeria monocytogenes
transmission: foodborn from contaminated lunch meat and transferred to babies (vertical)
prevention and treatment: avoid foods
cronobacter sakazakii
causative agent: cronobacter sakazakii
transmission: via contaminated powdered infant formula (vehicle)
prevention and treatment: use ready to feed and concentrated liquid formulas
infant vs wound vs foodborne botulism
infant: occurs when infant is fed honey
wound: when wound is infected
foodborne: contaminated food is consumed
arbovirus
causative agent: arbovirus
transmission: vector (through bites)
virulence factor: attachment,fusion
prevention and treatment: insect control
west nile
causative agent
transmission: vector (mosquito bites)
virulence factor: envelope allows it to pass undetected
prevention and treatment: no vaccine or treatment
rabies
causative agent: rabies virus
transmission: parenteral (bite trauma) or droplet contact
virulence factor: envelope glycoprotein
prevention and treatment: inactivated vaccine, passive and active immunization
zika
causative agent: zika virus
transmission: vertical, vector borne, sexual contact, likely through blood transfusions
virulence factor
prevention and treatment: supportive
polio
causative agent: poliovirus
transmission: fecal-oral or vehicle
virulence factor: attachment mechanisms
prevention and treatment: live attenuated or inactivated vaccine, no treatment
hsv
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
2 fungal causes of meningitis
cryptococcis (yeast) and coccidiomycosis (mold)
amoebic causes of meningoencephalitis
naegleria fowleriia and acanthaomeba
naegleria fowleriia
causative agent: naegleria fowleriia
transmission: vehicle (swimming in water)
virulence factor: invasiveness
prevention and treatment: limit freshwater entry in nasal passages
acanthamoeba
causative agent: acanthamoeba
transmission: direct contact
virulence factor: invasivness
prevention and treatment: surgical excision of granulomas
encephalitis
inflammation of the brain
acute vs subacute encephalitis
acute: caused by viruses borne by insects (west nile)
subacute: longer to show up
transmissible spongiform encephalopathies
causative agent proteinaceous infectious particles
transmission: vehicle (consumption of contaminated meat)
treatment/prevention: no cure, avoid contaminated meat and animals
