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IBSS 1503 M6
lectures 1,2,3,4
120
Science
Professional
11/29/2011

Additional Science Flashcards

 


 

Cards

Term
Difference between positive and negative stain:
Definition
Positive stains cells
Negative stains the extracellular materials, not the cell
Term
Gram stain procedure:
Definition
1. Crystal violet (purple)
2. Iodine - mordant (fixant)
3. Alcohol - decolorizer
4. Saffarnin - counterstain (red)
Term
What does bipolar staining look like and list an example.
Definition
Looks like a safety pin or 2 cocci ex. Yersinia pestis
Term
Medically significant gram positive bacteria: (14 total)
Definition
Staphylococcus
Streptococcus
Corynebacterium
Lactobacillus
Propionibacterium
Actinomyces
Bacillus
Clostridicum
Listeria
Peptostreptococcus
Bifidobacterium
Enterococcus
Garnerella (stains gram -)
Mobiluncus (stains gram -, very thin cell wall)
Term
Medically significant "kidney bean" shaped diplococci: (3 total)
Definition
Neisseria
Veillonella
Moraxella
Term
Medically significant "lancet-shaped" diplococci: (1)
Definition
Streptococcus pneumoniae
Term
Genera of acid fast positive (pink) bacteria: (2)
Definition
Mycobacteria
Nocardia
Term
Genera of bacterial Endospore-formers: (2)
Definition
Clostridium
Bacillus
Term
Genera of gram negative comma (vibrio) shaped bacteria: (3)
Definition
Vibrio
Helicobacter
Campylobacter
Term
Describe shape and arrangement of cocci:
Definition
shape = round
arrangments:
Staph (clusters)
Strep (chains)
Diplo (pairs)

*medically significant diplococci include Neisseria, Moraxella, Veillonella (look like two kidney beans) and Streptococcus pneumoniae (diplococcal pneumonia) looks like two footballs end to end...lancet shaped.
Term
Describe shape and arrangement of bacillus:
Definition
Shape = rod

Arrangement = random

Coccobacilllus - very short rods
Diptheroids (Corynebacterium) - club shaped
Actinomyces and Nocardia - thin branching filamentous rods
Term
Two arrangements of helicoidal bacteria:
Definition
Curved rod (Vibrio)
Spirochetal (Treponema)
Term
Describe size and shape of pleomorphic bacillus (Haemophilus influenzae):
Definition
varies in size and shape
Term
Describe chromosomal components and ribosomes of bacteria.
Definition
Bacterial chromosome (nucleoid) = single circular chromosome of double-stranded DNA.

Plasmids or Prophages may be present (extra chromosomes)

Ribosomes = 30S + 50S = 70S
Term
What type of T independent antigens are the structures on the outside of bacteria?
Definition
Type II - T independent antigens.
Term
The significance of Flagella:
Definition
1. Virulence: chemotaxis - motility in response to environment

2. H antigen - aids in serological identification of bacteria
Term
Significance of common phili (fimbriae):
Definition
Virulence: adherence, antiphagocytic, motility
Term
Significance of sex pili:
Definition
Transmission of genetic material (aids in antibiotic resistance)
Term
Composition of capsules/slime layers/exopolysaccharide of bacteria (K antigen).
Definition
Polysaccharide polymers of one of the following:

1. repeating units of a single sugar molecule (dextran, levan)
2. repeating units of complex polysaccharides of sugar, sugar alcohols, aminosugars, sugar acids.
3. repeating units of D-glutamic acid (forms polypeptide, ex. Bacillus anthracis)
Term
Define biofilms:
Definition
Protected structure of bacterial cells/microcolonies enmeshed in mucoid exopolysaccaharide adhering to a wet surface.

Bacteria in biofilms undergo a phenotypic change in that they PERSIST in the presence of antimicrobial agents that they are normally susceptible to.

**CDC estimates that 1/2 of human bacterial infections involve biofilms
Term
What are the three medical significances of bacterial capsules/biofilms?
Definition
1. ADHERENCE/virulence to host tissues and surfaces (colonization)

2. ANTIGEN used to IDENTIFY the agent in serodiagnosis

3. PROTECTION against phagocytosis, serum factors, antibodies, antibiotics
Term
Describe the structure of a bacterial cell membrane:
Definition
-Fluid mosaic model

Unit membrane: phopholipid bilayer w/ hydrophilic groups on top and bottoms and hydrophobic groups in middle.

Embedded polypeptides are stabilized in the membrane by divalent cations and hydrophobic interaction with fatty acid moiety of phospholipids

Unlike eucaryotes, bacterial CMs do not contain sterols EXCEPT Mycoplasma, Helicobacter, Ehrichia, Anaplasma
Term
What three bacterias contain sterols in the cell membranes? (4)
Definition

Mycoplasma Helicobacter Ehrlichia Anaplasma

MEHA

Term
Functions of CM in bacteria:
(3)
Definition
1. Permeability and transport

2. e-transport and oxidation phosphorylation (ATP)

3. Contains parts of biosynthetic pathways for cell wall. Site of septum formation in replication.
Term

Describe the difference between gram + and gram - bacteria:

(5)

Definition
1. Gram+ has a thicker peptidoglycan layer 2. Polysaccharides are covalently linked to peptidoglycan layer in Gram + cell wall, unlike gram - 3. Lipid molecules in cell membrane extend through the peptidoglycan layer in gram +, unlike gram - 4. Gram - cell wall has outer membrane w/ LPS, gram + does not. 5. peptidoglycan layer is located in the periplasm of the gram - cell wall.
Term
Function of cell walls (peptidoglycan) in both gram + and gram - bacteria:
Definition
1. interaction of bacterial w/ environment
-virulence and toxicity factors
- site of antigenic components (O antigen in gram -)
- anchors external structures (flagella, pilli, capsules)

2. site where differential staining occurs

3. shields against environment
- acts as molecular sieve (screens out lg molecules)
- prevents cell bursting, provides mechanical strength

4. Bacteria that lack peptidoglycan (ex. Mycoplasma - penicillin is not as effective)
Term
Define peptidoglycan.
Definition
Fabric shell encasing the cells, fabric is woven threads.

Shell is a network of polymers. Each polymer consists of repeating units containing N-acetylmuramic acid and N-acetylglucosamine.
Term
What does lysosome do to peptidoglycan?
Definition
lysosome acts on the aminosugar backbone, specifically it cleaves the B 1, 4 linkage
Term
The N-acetylmuramic acid subunits on different strands in peptidoglycan are cross-linked via aa sidechains. What does the crosslinking provide?
Definition
1 mechanical strength

2. prevention of cell bursting from osmotic pressure.
Term
Describe the cell wall of gram - bacteria.
Definition
Consists of periplasm and out membrane

periplasm has peptidoglycan layer, 1 layer thick

OM is lipid bilayer w/ phospholipid as inner leaflet and LPS as outer leaflet.

LPS is unique to OM of gram - bacteria. Helps resist dyes, hydrolytic enzymes and detergents that gram + are sensitive to.
Term
What is the major function of periplasm?
Definition
1. osmotic protections (**peptidoglycan is in periplasm**)

2. nutrient intake

3. sensory (chemotaxis)

4. degradative enzymes.
Term
Function of OM in gram - bacteria:
Definition
1. resistance to dyes, detergents, hydrolytic enzymes (lysozyme). it is a lipid bilayer so it is only permeable to hydrophobic substances. ***gram + lack OM and are susceptible to dyes and what not.
Term
OM structure:
Definition
Composed of lipopolysaccharide, phospholipid:
1. lipid bilayer (not phospholipid bilayer), differentially permeable.

2. proteins and lipoprotein

3. lipopolysaccharide (LPS) =endotoxin
Term
Structure of lipopolysaccharide LPS (endotoxin, O antigen)
ex: O157:H7
Definition
1. lipid A

2. core polysaccharide

3. terminal polysaccharide

4. lipooligiosaccharide (LOS)
Term
Lipid A of LPS:
Definition
-toxicity of LPS is due to Lipid A

composed of
disaccharides
phosphate groups
fatty acids (B-hydroxymyristic acid)
Term
Core polysaccharide of LPS:
Definition
-can contain sugards, aminosugar, sugar acids, sugar alcohols

-often contains KETODEOXYOCTULONATE (KDO).
Term
Terminal polysaccharide of LPS:
Definition
A unit of sugars, aminosugar, sugar acids or sugar alcohols repeated N number of times = O ANTIGEN OF ENTERICS.

Highly specific

ex. Salmonella
Term
Lipooligiosaccharides (LOS) of LPS:
Definition
Lack O anigentic chain, just contains lipid A and extended core.

examples:
Neisseria meningitidis
N. gonorrhoeae
Haemophilus influenzae
Haemophilus ducreyi
Term
Characteristics of LPS: (5)
Definition
1. structural component of OM

2. chromosomally encoded

3. broad specificty (effects many organ systems)

4. heat stable (even at autoclave temps, 121 degrees C)

5. Does not form toxoids
Term
LPS is broadly specific. What will it effect/activate?
(4)
Definition
1. pyrogenicity - EXOGENOUS PYROGEN

2. activates both alternative and classical complement pathways.

3. activates Hageman Factor XIII

4. induces a SIRS (systemic inflammatory response syndrome) pathway - produces most of the effects on the host through induction of endogenous mediators.
Term
What will affect the primary structure of lipid A (endotoxin)?
Definition
BURNING OR OXIDATION ONLY will detoxify endotoxin

this is unlike exotoxins which are inactivated by boiling for 10 min.
Term
Describe the clinical significance of LPS.
Definition
Has many physiological effects which may be factors in pathogenesis of gram - infections.

LPS may induce SIRS.
SIRS = similar to acute inflammation but on systemic scale w/ macrophages, PMNs, endothelial cells serving as effector cells
Term
SIRS may proceed to distributive shock, a type of hypovolemic shock. What is hypovolemic shock?
Definition
loss of fluid from vascular system causing bp to drop.  bp drop is NOT from vascular obstructive or cardiogenic reasons.
Term
Clinical definition of SIRs.
Definition
having TWO OR MORE of the following:

1. temp >38C or < 36C

2. tachcardia >90bpm

3. tachypnea >20 breaths/min

4. leukocytosis (>12,000/mm3) OR leukopenia (<4000/mm3)
Term
How does endotoxin activate SIRs?
Definition
-LPS binds to LBP (lipid binding protein in serum.

LPS-LBP complex interacts seperatly w/

1. membrane bound CD14 receptors on PMNs, macrophages, monocytes. LPS-CD14 binds to LPS signal transducer receptor protein (TLR) on macrophages and the TLR sends the signal through the cytoplasm to the nucleus.

2. soluble CD14 receptor present in serum, then bind to endothelial cells and cell dysfunction begins.
Term
Effect of LPS/endotoxin on patient:
(10)
Definition
1. endothelial dysfunciton (leakiness) leads to hypotension, vascular leak syndromes (ARDS)

2. TNF-a, IL1, IL6 are "early" primary endogenous mediators

3. release of arachadonic acid metabolites

4. release of bradykinin

5. activation of alternative and classical pathways of complement.

6. release of histamine from mast and basophils

7. release of NO from endothelial, vascular smooth muscle, cardiac smooth muscle cells, macrophages

8. activates Hageman factor (factor XII)

9. release of free radicals, especially superoxide anions.

10. peeps that survive hyperinflammatory phase enter a state of protracted immunosuppression (immunoparalysis) which manifests as loss of DTH response, failure to clear primary infection, development of new secondary infections, reactivation of dormant viruses (EBV, CMV, HSV)
Term
What does Hageman factor (FXIII) activate?
Definition
the clotting system (fibrin deposition) and fibrinolysis.

Fibrinolysis is then inhibited when plasminogen activator inhibitor is released.

Result = accumulation of undissolved thrombin in microcirculation (called disseminated intravascular coagulation DIC), leading to multiorgan failure (MOF), purpuric skin lesions.
Term
What must be present for sepsis?
Definition
1. infection (pneumonia, UTI, bacteremia)

2. SIRS

(bacteremia does not equal sepsis because BOTH infection and SIRS must be present)
Term
Definition of severe sepsis:
Definition
1. sepsis
2. organ failure (AKA organ dysfunction, multiorgan dynsfunction, multiorgan failure)
Term
Definition of septic shock:
Definition
1. severe sepsis
2. refractory hypotension
Term
Clinical manifestations of distributive shock aka hypovolemic shock:
(6)
Definition
1. fever or hypothermia
2. chills
3. leukopenia or leukocytosis
4. tachycardia and tachypnea
5. disseminated intravascular coagulation (DIC), nonblanching of skin
6. hypotension and shock which can cause MOF or multi organ dysfunciton (MOD) or organ dysfunction.
Term
How is SIRS detected?
Definition
Limulus
Amebocyte lysate test and/or monoclonal antibodies against LPS.
Detects presence of nanogram amounts of endotoxin (pyrogen = fever inducer)

Used in the pharmaceutical industry.
Term
Tx of SIRS
Definition
1. Protein C - inhibits clotting, activates fibrinolysis and inhibits inflammation

2. Early goal directed therapy (EGDT)
-includes sepsis resuscitation bundle and sepsis managment bundle
Term
What is done in the sepsis resuscitation bundle of EGDT?
(4)
Definition
1. serum lactate is measured

2. blood specimen is obtained for culture

3. administration of broad spectrum antibiotics

4. if hypotensive, fluids administered of isotonic crystalloid (saline) or iso-oncotic colloid (4% albumin) or vasopressin.
Term
What is done in the sepsis management bundle of EGDT? (2)
Definition
1. administration of corticosteroids 2. tight glycemic control
Term
Describe the structure of a gram + cell wall:
Definition
No OM
No LPS/endotoxin

Contains peptidoglycan, teichonic acid, lipoteichoic acid, numerous macromolecules.
Term
how is peptidoglycan different in gram + cell wall compared to gram - and how is it medically important
Definition
simliar composition to that of gram - but present in much larger amounts and more extensive cross linking. REASON FOR DIFFERENTIAL STAINING.

Med importance:
can induce production of TNFa, IL6, HYPOTENSIVE SHOCK/DISTRIBUTIVE SHOCK
Term
Describe lipoteichoic acid found in cell wall of gram + bacteria and its medical importance:
Definition
Polymer of glycerol or ribitol phosphate

Med import:
plays role in adherence, antiphagocytic
Term
Describe teichoic acids found in cell wall of gram + bacteria and its med importance:
Definition
polymer of glycerol or ribitol phosphate

med impor:
produces endotoxin like shock
interacts w/ C reactive protein
activates alt complement pathway
Term
Can DIC (disseminated intravascular coagulopathy) and shock also occur in etiologica agents lacking endotoxin (gram +, fungi, viral infections)?
Definition
Yes because they have other components capable of initiating release of endogenous mediators, producing SIRS.

The body is able to detect infection by different infectious agents (through multi TLR receptors specific for pathogen associated molecular patterns, PAMP).
Term
What are five PAMPs?
(pathogen associated molecular patterns)
Definition
1. peptidoglycan from certain bacteria

2. teichoic acids polymers

3. n-formyl methionine

4. CpG nucleotides (DNA vaccines)

5. LPS
Term
Properties of endospores
Definition
-can survive boiling, desiccation, chem resistant structures which are formed in response to adverse conditions.

Spores can remain dormant for decades until conditions for their gemination are present (H2O and nutrients).
Term
What are the two genera of endospore formers?
Definition
bacillus
clostridium
Term
What are viruses?
Definition
1. submicroscopic entities
2. OBLIGATE INTRACELLULAR PARASITES CAPABLE OF INFECTING SPECIFIC LIVING CELLS AND OF REPRODUCING IN SUCH CELLS ONLY.

3. consists of DNA or RNA and protein, some have envelope

4. possess a definite structure.
Term
Size of viruses?
Definition
15 to 300nm
Term
What makes up the structure of a virus?
(6)
Definition
1. virion (the complete viral particle)

2. nucleic acid

3. capsomeres

4. capsid

5. nucleocapsid

6. envelope
Term
What are the type of nucleic acids found in viruses?
Definition
1. dsDNA
2. ssDNA
3. +ssRNA
4 -ssRNA
5. dsRNA
Term
What is a capsomere?
Definition
part of virus

-protein subunits of capsid
-repetitive polypeptide subunits arranged in symmetric patterns = capsid
Term
What is a capsid?
Definition
make up virus

protein shell that covers the core of the NA genome and proteins

made up of capsomeres
Term
What is the nucleocapsid?
Definition
part of virus

capsid together w/ the NA genome and any associated proteins
Term
What is the envelope of a virus and what are the two types of envelopes?
Definition
envelope is a viral membrane of virus specific proteins plus host derived lipids and carbs.

the envelope is the only part of the virus that is from the host. the envelope can be taken from any envelop in the host (nuclear, ER, golgi, cytoplasmic membrane)

Types:
peplomer = spikes. plays role in attachment

tegument aka matrix protein: shapeless form b/w nucleocapsid and envelope that mediates interaction b/w capsid and envelope.
Term
Define viroid.
Definition
naked RNA virus, term is confined to plant viruses
Term
Define prion
Definition
infections protein (NOT A VIRUS). which causes disease in CNS
Term
How are animal viruses classified?
(4 ways)
Definition
1. type of NA
2. capside symmetry
icosahedral -caspsomeres arranged in triangles that form a symmetric shape
helical - capsomeres arranged in hollow core that appears helix shpaed

3. presence or absence of envelope

4. quantitative measurement
icosahedral symmetry viruses the # of capsomeres is quantified
helical symmetry - diameter of helix is measure
Term
What are the six stages of viral replication?
Definition
1. attachment
2. penetration
3. uncoating
4. macromolecular synthesis
5. assembly - viruses autoassemble
6. release - target of antiviral therapy for at least one virus
Term
attachment:
Definition
1st stage of virus replication

virus ligand binds to a specific receptor site.
specificty of attachment determines both the host range of the virus and the tissue tropism
Term
penetration
Definition
2nd stage of viral replication

virion can enter the cell by one of several methods
Term
uncoating
Definition
3rd stage of viral replicaiton

removal of protective coat w/ release of NA.
infectivity is lost
-this the target of antiviral therapy for at least one virus
Term
Macromolecular synthesis
Definition
4th stage of viral replication

virus specific mRNA must be transcribed from the viral NA. after transcription, host cell components are used to translate the mRNA into protein.
Term
molecular synthesis of DNA viruses:
Definition
viral specific mRNA is made the same way as the host specific mRNA
Term
macromolecular synthesis of +ssRNA:
Definition
viral NA SERVES AS mRNA but they must encode for an RNA-DEPENDENT RNA POLYMERASE to make the antisense RNA to produce the viral genome (+ssRNA)
Term
macromolecular synthesis of retroviruses
Definition
retroviruses have a REVERSE TRANSCRIPTASE (RNA DEPENDENT-DNA POLYMERASE) which transcribes the +ssRNA to DNA, then the mRNA is transcribed from the viral specific DNA. This is the target for many anti HIV drugs.
Term
How do viruses enter our bodies?
(5)
Definition
1. aerosol - most difficult to control and most common
2. direct contact
3. ingestion - 2ND MOST DIFFICULT to control and 2nd most common means of entry
4. injection
5. transplacental
Term
What is viral tropism?
Definition
the specificty of a virus for a particular host tissue

virus-receptor interactions are a major determinant of infectivity
Term
What are the two types of viral infections?
Definition
1. productive (nonlethal and cell damage/death)

2. persistent (latent, chronic slow)
Term
Nonlethal productive infections:
Definition
sustained release in absence of lysis (ex. rhinovirus)
Term
Cell damage death productive infections:
Definition
LYTIC - virus replication results in cell death (ex. polio, influenza via VIRAL MODIFICATIONS/DAMAGE OF HOST CELLS).

1. host cell macromolecular synthesis is stopped
2. CYTOPATHIC EFFECT (CPE) of viral proteins on host cells (toxic to cell)
3. inclusion bodies and cell fusion (SYNCYTIA formation)
4. chromosomal alterations can lead to oncogenesis/malignant transformations
5. induce apoptosis
Term
latent persistent infections:
Definition
intermittent acute episodes of disease between which there is an absence of infectious particles (HSV, varicella-zoster virus)
Term
chronic persist infections:
Definition
continued presence of virus, but absence of disease (cytomegalovirus, herpes virus 6 & 7, hep B) or is associated w/ late immunopathologic disease (HBV -> cirrhosis of liver or hepatocellular cancer)
Term
slow persistent infections:
Definition
long incubation period then a slow progressive disease occurs (subacute sclerosiing panencephalitis SSPE)

no infectious virion may be detected
Term
Define malignant transformation
Definition
conversion of a cell from restricted growth to unrestricted growth, which is characteristic of tumors.
Term
characteristics of a transformed cell:
Definition
1. loss of contact inhibition
2. appearance of new antigens (tumor specific antigens)
3. other changes (metabolic, genetic)
Term
RNA tumor viruses:
3 examples
Definition
1. HTLV/Human T cell leukemia viruses - primary cell target is the T helper cell

2. lymphotrophic retroviruses

3. Adult T cell leukemia (caused or associated w/ HTLV-1)
Term
DNA tumor viruses:
3 examples
Definition
1. HPV
2. EBV (burkitts lymphoma, nasopharyngeal carcinoma)
3. HBV - priimary hepatocellular carcinoma
Term
How are viral agents of benign neoplasms different from malignant neoplasms and list two examples.
Definition
Benign are still somewhat organized and will not invade adjacent tissue and undergo metastasis

1. HUMAN WART VIRUS - verruca lesions (skin warts), condyloma acuminatum (genital warts)

2. POXVIRUS - molluscum contagiosum
Term
List 4 immune responses to viral infection:
Definition
1. physcial barriers and phagocytes

2. cellular immunity (T lymphocytes, lymphokines, NK cells)

3. Humoral immunity
-virus neutralizaiton via antibody to receptors on virus, prevents virus from attaching. ANTIBODIES ARE VIRUS SPECIFIC NOT HOST SPECIFIC.
- complement and/or antibody dependent lysis of virus infected cells.

4. Non specific
-INTERFERONS - antiviral agents. Natural cell products that stimulate antiviral resistance by interfering w/ virus protein synthesis. HOST SPECIFIC, NOT VIRAL SPECIFIC
Term
Characteristics of fungi:
Definition
-eukaryotic (nucleus, membrane, cytoplasmic organelles)

-reproduce sexually or asexually. fungi are classified on type of SEXUAL spores produced.
1. fungi imperfecti: sexual stage not discovered, cause disease in humans
2. other subdivision: sexual stage described
Term
Morphological forms of fungi
Definition
1. yeasts
2. mycelial fungi
3. dimorphism
4. types of sexual spores
Term
yeasts:
Definition
unicelluar
asexual reproduction by budding
Term
mycelial fungi:
Definition
mold form
growth by elongation of hyphae to form a mycelium. Sexual and asexual spores are produced

hyphae: CELLS are branching cylindrical tubules , septa or crosswalks

mycelium: mass of intertwined hyphae
Term
Dimorphism:
Definition
grows as a mycelial at room temp
grows as yeast at 37degree C

growth is temp dependent
Term
Blastospores:
Definition
type of asexual spore
another name for a yeast
Term
Macroconidia and microconidia:
Definition
type of asexual spore
large and small spores not enclosed in any structure (naked spores)

micro - sm enough to get into alveoli when inhaled, infectious form of fungi

macro - infectious form of fungi that infect skin (dermatophytes)
Term
arthrospores:
Definition
asexual

heavy walled spores produced by fragmentation of hyphae

infectious
Term
How do fungi growth?
Definition
Heterotropic - require exogenous organic energy

can grow in soil and in body

prefer aerobic condtions
Term
3 types of fungal cell structure:
Definition
1. capsule (ex Cryptococcus neoformans)

2. cell wall complex (chitin, glycoproteins)

3. cytoplasmic membrane (ergosterol inhibited by Amphotericin B)
Term
What is essential for the control of systemic mycotic infections and the successful resolution of all mycotic infections?
Definition
cell-mediated immunity
Term
What are the factors that predispose someone to fungal infections?
Definition
1. environment
2. host factors (age, gender, metabolic abnormalities, immunosuppression, pregnancy, diabetes, oral contraceptives, trauma and burns)
Term
Define symbiosis:
Definition
close association of 2 different organisms
Term
Define mutalism:
Definition
beneficial association to both
Term
define commensalism:
Definition
beneficial association for one without affecting the other
Term
define parasitism:
Definition
beneficial association for one and detrimental for the other
Term
Describe classification of the ANIMAL KINGDOM/eucaryotic:
Definition
lack cell wals

may have walls on cyst forms
flexible cuticles or chitinous exoskeletons
Term
Briefly describe protozoa and list 4 types:
Definition
microscopic
single cells

1. RHIZOPODS (amoebas): motile by cytoplasmic extensions/pseudopodia

2. FLAGELLATES: motile by means of flagella

3. CILIATES: motile by means of cilia

4. SPOROZOANS: complex life cycles w/ asexual and sexual stages.
Term
Describe helminths and list two types:
Definition
-macroscopic as adults, eggs are microscopic
-mostly monoecious (male and female organs on same individual)

1. PLATYHELMINTHES (FLATWORMS)
- TREMATODES - FLUKES
- CESTODES - TAPEWORMS

2. NEMATHELMINTHES - ROUNDWORMS/NEMATODES
dioecious (seperate male and female worms)
Term
Arthropodes:
describe and list a few examples
Definition
chitinous exoskeltons

ex. lice, mites, ticks
Term
What are the 3 factors affecting disease production by parasites?
Definition
1. species
2. size of parasite
3. unnatural host (visceral larva migrans, human disease caused by dog round worm)
Term
Definitive host:
Definition
host which harbors adult or sexual stage of parasite
Term
Intermediate host:
Definition
host in which asexual stage occurs
Term
What 3 clinical aspects are essential in understanding a disease caused by a parasite?
Definition
1. where the agent travels in host
2. organs infected
3. host immune response
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