Chapter 18 study guide

What is the etiological agent of meningococcal meningitis?

Neisseria meningitidis Gram negative and encapsulated

What is chronic wasting disease?

Progressive, fatal neurological disease of captive or free-ranging deer

What are Negri bodies?

Small clusters of virus inside the neurons

What is scrapie?

Spongiform encephalopathy of sheep

What is the etiological agent of pneumococcal meningitis?

Streptococcus pneumoniae gram positive and non-encapsulated

What are the two neuroinvasive arboviruses that are most seen in the United States?

West Nile and La Crosse virus

How is a normal prion protein (denoted as PrPc) changed to the infectious form (denoted as PrPsc)?

When the protein encounters an abnormally shaped version of itself sc stands for scrapie-like

What are neurotransmitters?

a chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure.

What is flaccid paralysis?

a state in which the muscles are limp and cannot contract

When does polio-related flaccid paralysis occur?

7 to 21 days after infection

What are two tests that can differentiate between viral and bacterial meningitis?

A blood test and lumbar puncture

blood-brain barrier

A mechanism that prevents certain molecule from entering the brain but allows others to cross

What is poliomyelitis?

A viral infection of the nerves controlling skeletal muscles.

What animal is the natural carrier of Mycobacterium leprae?

Amradillos, due to their cooler body temperature

What disease can be contracted if West Nile virus becomes systemic?

Arboviral encephalitis

What is the danger of S. pneumoniae exotoxin?

Causes pneumonia, sinusitis, ear infections, blood infections and meningitis

What is the etiological agent of tetanus?

Clostridium tetani Found in soil Associated with deep wounds

Infection with which fungal organism is the leading cause of death in HIV/AIDS patients?

Cryptococcus neoformans

What is the etiological agent of cryptococcosis?

Cryptococcus neoformans and Cryptococcus gattii A fungus that is made by bird droppings

Name the two scientists that won the Nobel Peace Prizes for their work deducing that prions were the cause of certain spongiform diseases

Daniel Gajdusek and Stanley Prusiner

True or false Listeria monocytogenes only grows in a narrow pH range but can grow at a wide range of temperatures.

False, it grows in a wide pH and temperature range

True or false The nervous system contains a rich diversity of normal microbiota that functions to compete with infecting pathogens.

False, no normal microbiota is present to compete with infecting pathogens.

True or false Due to their small size, bacteria can more easily pass through the blood-brain barrier and infect the nervous system than viruses.

False, viruses are smaller than bacteria

What does it mean when polio is cytolytic? How does this affect the nervous system?

It ruptures cells after viral infection and replication Causing severe inflammation

What is the etiological agent of Listeria meningitis?

Listeria monocytogenes transmitted by contaminated foods Gram-positive rod

What molecule is a prion?

Misfolded protein Causes creutzfeldt-jakob disease

What is the etiological agent of Hansen's disease?

Mycobacterium leprae

What is the etiological agent of primary amoebic meningoencephalitis (PAM)?

Naegleria fowleri Caught by swimming in warm stagnant water AKA brain-eating amoeba

How were arboviruses named?

Named for arthropod (insect) borne

What area is affected by botulism toxin?

The body`s nerves

Why shouldn't pregnant women clean cat litter boxes?

The disease can transmit from mother to fetus

What is the etiological agent of toxoplasmosis?

Toxoplasma gondii Carried by cats

True or false Bacterial meningitis is more dangerous than viral meningitis; up to 20 percent of patients suffer long-term disabilities including brain damage and hearing loss.

True

What is the etiological agent of African sleeping sickness?

Trypanosoma brucei (flagellated protozoan)

What two medical treatments are included in rabies post-exposure prophylaxis?

antirabies antibodies and inactivated vaccine for rabies

What type of immunity is derived from antirabies antibodies and inactivated vaccine treatments?

artificially acquired active immunity

What is the gut-brain axis?

bi-directional communication between the gut and the central nervous system

What is the danger of C. botulinum endospores to humans?

blocking nerve functions and can lead to respiratory and muscular paralysis

What is BSE?

bovine spongiform encephalopathy

sensory neuron function

carries impulses from a sense receptor to the brain or spinal cord

What are the two divisions of the nervous system?

central nervous system and peripheral nervous system

interneuron function

connects sensory and motor neurons

What are the two main viruses that cause meningitis?

coxsackievirus and polivirus

What is the function of cerebrospinal fluid (CSF) and where is it located?

cushions and nourishes the CNS found in the subarachnoid space (between the meninges)

What is the most common domesticated animal reservoir for rabies?

dogs

How did people contract the variant Creutzfeldt-Jakob disease. ?

eating beef contaminated with BSE prions

What is the advantage of Listeria monocytogenes' intracellular lifestyle?

escapes phagocytosis

What are the "triad" symptoms of meningitis?

fever, neck stiffness and headache

Botulism toxin causes what type of paralysis?

flaccid paralysis

Functions of the meninges

forms a protective layer around the CNS supplies nutrients to the CNS removes waste from the CNS

What microbe is the leading cause of sporadic fatal encephalitis (also called HSE) worldwide?

herpes simplex virus 1 (HSE is herpes simplex encephalitis)

What is encephalitis?

inflammation of the brain

What is meningoencephalitis?

inflammation of the brain and meninges

What is meningitis?

inflammation of the meninges

What is the common name for tetanus?

lockjaw, caused by tentanospasmin and contracts the muscle without relaxing

What infection is a lumbar puncture used to diagnose?

meningitis

What are most human prion cases due to?

non-variant CJD and the elderly are most at risk

Which bacteria cause most cases of meningitis in the United States?

pneumococcal meningitis

What is the etiological agent of poliomyelitis?

poliovirus

What diagnostic tool is used to diagnose polio?

polymerase chain reaction (PCR) test

what is the function of cerebrospinal fluid?

protects and nourishes the brain and spinal cord

Categories of neurons

sensory, motor, interneurons

Where is cerebrospinal fluid located?

subarachnoid space

What is the difference between symmetric and asymmetric paralysis?

symmetric affects both sides of the body asymmetric affects one side of the body

What structural feature protects poliovirus against stomach acid?

tough protein coat

motor neuron function

transmits impulses from the brain or spinal cord to a muscle or gland

What is the difference between the tuberculoid and lepromatous forms of Hansen's disease?

tuberculoid have fewer and more isolated skin plaques lepromatous causes irreversible tissue damage in macules, papules and nodules

Why hasn't there been a case of polio in the United States since 1979?

vaccine development

What is mylein?

white fatty tissue that insulates axons

What is the term for infections that are spread from animals to humans?

zoonosis

How does a person contract African sleeping sickness?

Blood-sucking tsetse fly

What bacteria and serotype causes Haemophilus meningitis?

H. influenzae Type b

What is the vaccine administered in the United States to protect against Haemophilus meningitis called?

Hib vaccine

What type of vaccine formulation are Salk (IPV) and Sabin (OPV) vaccines.

Salk is made of inactivated polioviruses Sabin is made of live-attenuated polioviruses

What is the blood-brain barrier?

Blood vessels (capillaries) that selectively let certain substances enter the brain tissue and keep other substances out

How is West Nile virus contracted?

By infect mosquitoes

What is the etiological agent of botulism?

Clostridium botulinum Gram-positive and rod shaped Found in canned food

How is neonatal meningitis contracted?

Bacteria passes to a neonate from their mother during delivery

What is the diagnostic sign of rabies?

Formation of Negri Bodies

What is the drawback of the Sabin vaccine?

It causes disease in immunocompromised people

How can the bacteria remain intracellular but still infect neighboring cells?

Using a protein known as ActA