Exam 2 Flashcards
A smaller organism that lives on/in and at the expense of a larger organism
Parasite
What are the 3 main classes of parasites that can cause disease in humans?
- Helminths
- Ectoparasites
- Protozoa
What is Toxocara canis?
Round worm
What are the 3 characteristics we can look at when diagnosing parasites
SIS
Host Species
Site of Infection
Size of Parasite
What are the 4 factors used to treat/prevent parasite infections?
- Parasiticides
- Sustainable management of the host
- Management of the environment
- Use life cycle to determine treatment and prevention
What must we understand in order to treat parasitic infection?
Taxonomic classification host identification life cycle site of infection parthenogenesis and lesions clinical signs diagnosis treatment and prevention
What are nematodes?
Roundworms
What are cestodes
Tapeworms
Are there different genders of roundworms?
Yes
Are there different genders of Tapeworms?
Nope, hermaphrodites
What are the 2 segments of the tapeworm?
- scolex- holdfast organ
2. strobila- body with proglottids
What is the only type of worm with proglottids
Tapeworms
What are trematodes?
Flukes
do flukes have a direct or lindirect life cycle?
Indirect
What are the 2 classifications of Arthropods
Insects and arachnids
List the different types of parasitic insects
Flies, Fleas, Lice, Hemiptera (bed bugs)
List the 2 types of parasitic arachnids
Ticks and Mites
What are 3 characteristics you can use to identify Insects
- 3 pairs of legs
- 3 body segments: Head, thorax, abdoment
3 Antenna
What are 3 characteristis you can use to identify adult arachnids
- 4 pairs of legs ( 3 in larvae)
- 2 body segments : Cephalo-thorax and abdomen
- Palps, but no antennae
What is a scutum?
hard body plate covering arachnids
What are protozoa?
unicellular eukaryotic animals
How are protozoa classified
based on their mode of locomotion
what are the different classifications of protozoa based on locomotion?
- Pseudopodia
- flagella
- gliding movements
- cilia
What are the 3 groups of eukaryotic organisms that afflict health and wellbeing of animals?
- Protozoa
- Helminths
- Arthropods
Which type of parasites are single celled and nucleated
Protozoa
Which type of parasite are worm- like animals, showing differentiation
Helminths
Which type of parasites are ectoparasites?
Arthropods
What are the 3 categories of Helminths we talked about in class?
- Nematode (roundworm)
- Cestode (Tapeworms)
- Trematode (Flukes)
What are the 2 types of Trematodes we talked aboout?
Arachnids and insects
What are the 2 general classifications of parasites
- Ectoparasites
Lives on host - Endoparasites
Lives in host
Which general classification of parasites cause infestations?
Ectoparasites
Which general classification of parasites cause infections?
Endoparasites
What is a Definitive host?
Harbors adult or sexual stage of parasite
What is an intermediate host?
Harbors larval or asexual stage of parasite
What is and incidental host?
an unusual host, unnecessary for the maintenance of the parasite in nature
What is Acquired immunity?
conferred by a host’s specific immunity response developed as a result of a previous parasitic infection
What is premunition?
resistance to reinfection or superinfection conferred by presence of parasites that are alive but are in check by host immunity.
Ex: toxoplasmosis
What are 6 common routes of parasite entry
- Ingestion
- Skin penetration
- Transplacental
- Transmammary
- Arthropod bite
- Sexual contact
What are the 3 ways parasites cause mechanical tissue damage?
- Blockage of internal organs
- Pressure atrophy
- Migration through tissues
What are the 3 toxic parasite products?
- destructive enzymes
- endotoxins
- toxic secretions
What is innate immune Response?
Functions in normal host without prior exposure to invading microbes
What is Adaptive immune response?
consists of antibody response and lymphocyte-mediated response tailored to a particular microbial infection and characterized by memory
What is the response time for innate immunity?
Minutes/hours
What is the response time for adaptive immunity
Days
Which of the 2 types of immunity has persistent memory?
Adaptive
Making one species innately susceptible and another resistant to certain infections
Constitutional factors
What are 3 natural barriers against parasite infections
- mechanical
- chemical
- microbiological
What are the 2 types of interferons?
IFN-a, IFN-b
What are the 3 jobs of IFNs
- Induce resistance to viral replication in all cells
- Inc. MHC class I expression and antigen presentation in all cells
- Activate NK cells to kill virus-infected cells
What is another name for IFN alpha
Leukocyte interferon
What is another name for IFN beta
Fibroblast interferon
What are the 2 types of interferons?
Type I and Type II
Which type of interferon is Alpha?
Type I
Which type of interferon is beta?
Type II
What are the 3 types of lymphocytes?
B cells, T cells, Large granular lymphocytes
What is phagocytosis?
Engulfment and digestion of infectious agent or other foreign bodies by phagocytic cells
what are the 2 phagocytic cells?
Phagocytes and neutrophils
What are the 5 steps of phagocytisis?
- Bacterium becomes attached to pseudopodia
- Bacterium is ingested, forming phagosome
- Phagosome fuses with lysosome
- Lysosomal enzymes digest captured material
- Digestion products are released from cell
How does the innate immune system distinguish infected cells from uninfected cells?
Pattern recognition receptors (PRR) and missing/altered self receptors (NKcells)
How does the adaptive immune system distinguish infected cells from uninfected cells?
Antigen presentation (MHC), Antibodies, T cell receptors
What are the 3 types of pattern recognition receptors (PRR)
- Toll like receptors
- Rig like receptors
- Complement
What do PRR recognize?
PAMP Pathogen associated molecular patterns
What cleans up dead neutrophils?
Macrophages
What are neutrophils?
Function to phagocytize and kill extracellular bacterial and yeast pathogens in acute inflamation
Where are neutrophils stored when not needed?
bone marrow
What type of WBC is important in defense against helminths
Eosinophils
Large granular lymphocytes that lack antigen specific receptors
Natural killer cells
What stimulates NK cells to divide?
IFN produced by infected cells and dendritic cells
How do NK cells kill
Releasing perforins and granzymes that perforate membranes and trigger caspase mediated cell death
What are the 2 interactions needed in order for NK cells to recognize if infected or not?
- activating
2. blocking
Which molecule is responsible for the activating interaction of NK cells?
Virus infection- associated ligand
Which molecule is responsible for the Blocking interaction of NK cells?
MHC I molecule
What is a complement?
host defense against microbial infections
How is the inactive form of a complement activated?
Enzymatic cleavage
What are the 3 complement pathways?
- Classical pathway
- Alternative pathway
- Lectin pathway
What is the name of the pathway that all activation pathways turn into?
Terminal pathway
What is the activator of the classical pathway?
Binding of Ab to Ag, C1 reactive protein binding
What activates the lectin pathway?
mannan binding lectin (MBL) binds mannose on pathogen surfaces
What activates the alternative pathway?
contact of microbial cell wall with C3
What are the 3 consequences of complement activation?
- Lysis
- opsonization
- activationof inflammatory response
What are the 2 distinct types of adaptive immune responses
Primary and secondary humoral immunity
What is humoral immunity?
Mediated by antibodies secreted by antigen activated b cells and their progeny plasma cells
What are some characteristics of the secondary humoral response?
shorter lag phase greater magnitude class switched IgG
What are 2 jobs of antigens
- induce specific adaptive immune responses
2. react specifically with products of the response
What are paratopes?
Part of an antibody which recognizes an antigen, the antigen binding site of an antibody
What does MHC stand for?
Major histocompatibility complex
what recognizes native Ag w/o processing or MHC?
BCRs and Abs
What recognizes processed Ag on MHC?
TCRs