question

two body surfaces that have the initial exposure to an infectious agent

answer

skin
mucosal membranes

question

name four body cavities lined with mucous membranes (tracts)

answer

respiratory tract
genital tract
urinary tract
gastrointestinal tract

question

what type of defense is (the inpregnability of skin)?

answer

mechanical

question

what type of defense is ( the presence of mucous on surfaces of body cavities)?

answer

mechanical

question

are mechanical defenses specific or non specific?

answer

non-specific

question

the constant shedding of old dead cells of skin and mucosal surfaces is a ...... defence and also called .......

answer

mechanical
desquamation

question

the flow of liquids out from the body is what type of defense?

answer

mechanical

question

examples of fluids flowing from the body

answer

urination, diarrhea, tearing of the eyes,mucous removed from the respiratory tract

question

what are the three catergories of non-specific body defenses against infectious agents?

answer

Mechanical
chemical
microbial antagonism

question

Acid pH of stomach, urine and skin inhibits growth/survival of microorganisms is a ........ defense

answer

Chemical

question

fatty acids on the skin inhibiting the growth of some bacteria is a ...... defense

answer

chemical

question

Lysozyme, an enzyme in mucous secretions degrading bacterial cell walls is what kind of defense?

answer

chemical

question

Normal nora microorganisms, usually bacteria, prevent the growth of other pathogenic microorganisms is called......

answer

microbial antagonism

question

name two ways normal flora prevent the growth of pathogens in the body

answer

1. producing substances that are toxic to pathogens.
2. consume nutrients that are needed by infectious agents

question

Lactobacillus species, normal flora of the vagina, prevent growth of Candida (yeast) species that may cause infections. this is an example of....

answer

microbial antagonism

question

Normal flora of the gastrointestinal tract prevents growth of Clostridium difficile, an important cause of severe diarrhea in humans. this is an example of.....

answer

microbial antagonism

question

.......causes white blood cells to leave the blood circulation and to infiltrate into damaged tissues

answer

inflammation

question

what is the purpose of inflammation?

answer

a.The destruction andlor removal of injurious agents and dead cells from tissues
b. Results in repair of damaged tissues

question

what is inflammation induced by?

answer

a.The presence of microorganisms in tissues
b.Physical injury induced by trauma, or exposure to heat or chemicals

question

These are the four clinical signs of ........
a.Rubor (redness)
b.Dolor (pain)
c.Calor (heat)
d.tumor (swelling)

answer

inflammation

question

what are the mediators in inflammation?

answer

small molecules produced by mast cells at the site of injury

question

name two things that mediators cause

answer

1. vasodialation
2.emigration

question

define vasodialation

answer

(a)Dilation of vessels and capillaries
(b)White blood cells (neutrophils) stick to inner surface of vessel walls, called margination, and then they enter tissues

question

define emigration

answer

(a)White blood cells migrate through tissues toward the damaged area by a process called diapedesis
(b)They are propelled to site by mediators called chemotactic agents

question

(a)neulrophils (phagocytic)
(b)basophils
these are types of......
(c)eosinophils

answer

Types of polymorphonuclear leukocytes

question

(a) macrophagesfmonocytcs (phagocytic) b.lymphocytes
these are types of......

answer

mononuclear leukocytes

question

Blood is composed of what three things?

answer

a.Red blood cells
b.Platelets
c.White blood cells; two major classes

question

what are the two classes of white blood cells

answer

Polymorphonuclear leukocytes (granulocytes
Mononuclear leukocytes (agranulocytes

question

summarize Phagocytosis (cell eating) eliminates microorganisms; mechanism

answer

(1)Microorganism attaches to white blood by interaction between molecules of microorganism and white blood cell
(2)Microorganism is engulfed in phagosome as it ellters white blood cell
(3)Lysosomes, small, membrane-bound bags also called granules, in white blood cells contain toxic substances
(4)The lysosomes fuse with the phagosomes, the toxic substances enters and destroy the microorganism.

question

small, membrane-bound bags also called granules, in white blood cells contain toxic substances

answer

Lysosomes

question

describe three ways that a fever helps overcome disease

answer

a.Higher temperatures inactivate enzymes and toxins of the infectious agent
b. It incrreases host metabolism increasing the activity of protective mechanisms
c.It causes the individual to feel ill, and wanting rest that prevents damage.

question

Infection results in increased body temperatures; >37.8 C (100.5 F)
2. is induced by imflammatory process and by other means
3.Increased body temperature helps to eliminates. an infectious agents:

answer

fever

question

define compliment

answer

Complement is a series of 20 different kinds of proteins present in body fluids

question

how are the compliment proteins activated?

answer

the presence of microorganisms

question

a.Causes an increase
b.Enhances phagocytosis
c.Causes damage to the microbial cell membrane

answer

the activation of compliment does these things

question

polypeptide produced by some virally infected cells

answer

interferon

question

how do interferons help protect against viral infection?

answer

These interferon molecules enter other non-infected cells and make them resistant to viral infection

question

define infection

answer

describes the colonization and grovvth of pathogenic microorganisms
in/on an individual (host)

question

define infectious disease

answer

when infection causes pathology (illness)

question

when one organism benefits, the other remains unaffected. this is the definitions of....

answer

commenalism

question

define mutualism

answer

when both organisms benefit

question

define parasitism

answer

when one organism (pathogen) benefits to the detriment of the other

question

describes the association of tv,o different organism species; e.g. humans and microorganisms; this is known as.....

answer

Symbiosis

question

what are the three kinds of symbiotic relationships?

answer

commenalism
mutualism
parasitism

question

(also called microbiota) has a symbiotic association with the host (human).
1. They colonize of body surfaces and cavities after birth
2.They are mostly bacteria
3.Many are beneficial to host

answer

Normal flora

question

what are some of the benefits of normal flora?

answer

a. They provide essential substances eg, vitamins
b. They prevent growth of pathogens (microbial antagonism

question

two ways normal flora display microbial antagonism.

answer

(1)produce chemicals toxic to pathogens
(2) consume essential nutrients needed by pathogens

question

Microorganisms that form the symbiotic relationship are called (three of them)

answer

saprobes
opportunists
pathogens

question

microorganisms that have no ability to cause disease

answer

saprobes

question

these are able to cause disease when present in unusual body sites or when host is debilitated

answer

opportunists

question

these are able to cause disease in a healthy host; they have properties that help them to cause disease ie. virulence factors

answer

Pathogens

question

define noncommunicable disease

answer

they are not spread from one host to another

question

these may be spread from one host to another.

answer

communicable disease

question

Contagious diseases

answer

these are easily spread from one host to another.

question

the four terms used in regard to incidence of disease.

answer

sporadic
endemic
epidemic
pandemic

question

sporadic diseases occur

answer

occasionally

question

endemic diseases are

answer

a disease that is always present in a population at a certain rate.

question

Epidemic disease

answer

one that occurs at an unusually high incidence in a population

question

define pandemic

answer

a world wide epidemic

question

three terms used to decbribe the severity and duration of diseases

answer

acute
chronic
latent

question

acute disease

answer

one that develops quickly with short duration

question

chronic disease

answer

one that develops more slowly, less severe and with slow recovery

question

Latent Disease

answer

a disease in which infectious agent does not cause overt symptoms, the infectious agent remains inactive for a period of time; symptoms may occur later

question

Local infection

answer

involves a limited area of the body. does not spread

question

an infection in where infectious agent spreads through the body by way of the blood stream and/or lymphatics

answer

Systemic infection

question

primary infection

answer

a disease that occurs in a healthy person

question

a disease that occurs in an individual who is weakened or debilitated by a primmy infection

answer

secondary infection

question

interval between infection of agent and onset of symptoms

answer

incubation period

question

podromal period

answer

initial. mild, more generalized symptoms

question

when symptoms begin to subside

answer

Period of deciine

question

Period of convalescence

answer

when patient gradually recovers completely

question

illness

answer

development of typical symptoms (syndrome) associated with a particular agent

question

is where the infectious agent survives and grows and from which is exposed to an individual.

answer

Reservoir of infectious agents

question

Endogenous diseases

answer

caused by individual's own normal nora

question

Exogenous diseases are caused by....

answer

infectious agents that arc acquired from the outside: e.g.
a.Other humans
b.Animals (wild or domesticated)
c.Food
d.Water
e.Soil

question

name three types of contact transmission

answer

1.direct contact
2. indirect contact
3.droplet transmisssion

question

what kind of contact is touching, kissing and sexual contact?

answer

direct contact

question

indirect contact transmission

answer

contact with contaminated inanimate objects (fomites)

question

Droplet transmission

answer

infectious agent in infected mucous droplets, less than 1 meter

question

infectious agent carried inion a non viable carrier;

answer

Vehicle transmission

question

name three non viable carriers of infection

answer

1 food
2 water
3 air

question

define vector transmission

answer

infectious agent carried by a living carrier, usually an arthropod, from one host to another;

question

name the two types of vector transmission

answer

a, Mechanical; organism on surface of vector, fly
b. Biological; more complex, spread by bite of arthropod

question

name four ways we control disease

answer

A. Eliminate reservoir of infectious agent
B. Interrupt means of transmission
C. Enhance immunity of susceptible individuals
D. Prophylactic administration of antimicrobials

question

where are nosocomial infections aquired?

answer

hospitals

question

name three reasons that nosocomial infections occur

answer

1. Patients are debilitated
2. Patients have wounds, indwelling catheters, which allow entrance of infectious agents
3 Patients are exposed to "hospital" strains of infectious agents.
More resistant
Accumulate in hospital due to usc 0f antimicrobials

question

three ways nosocomial infections are controlled in hospitals

answer

1.All infectious are monl tored
2.Sources of agents arc found an eliminated
3.Procedures are changed to prevent infection

question

Some bacteria (called pathogens) are able to cause disease because they possess certain characteristics; these characteristics are called

answer

virulence factors;

question

name five virulence factors

answer

1. adhesins
2.invasins
3.evasins
4.exotoxin
5.endotoxin

question

these are chemical substances on the bacterial surface that binds them to host surfaces, usually to mucous membranes.
1. pili (fimbriae)
2. cell surface molucules.
These are called

answer

Adhesins

question

Define invasins

answer

these are preducts of the bacterial cell that allows them to enter tissues and spread;

question

name three invasins and what they do

answer

1. Enzymes that eliminate barriers at surfaces
2.Hyaluronidase -"spreading factor", an enzyme that degrades molecules that hold host cells together; allows the organism to spread in tissues
3.Fibrinolysin -enzymes that degrade blood clots that allows the organism to spread

question

define evasins

answer

these are molecules that anow the infectious agent to survive in the host;

question

1.Capsules -prevents phagocytosis
2.Cell wall molecules -these molecules prevent phagocytosis
3.Coagulase -an enzyme that facilitates blood clotting; this protects the bacteria
4.Leukoeidins -these are proteins that damage membranes of white blood cells; they allow bacteria to survive.

answer

four examples of evasins

question

-these are bacterial substances that cause damage to the host;

answer

Toxic substances

question

name four evasins

answer

1.
Capsules -prevents phagocytosis
2.
Cell wall molecules -these molecules prevent phagocytosis
3.
Coagulase -an enzyme that facilitates blood clotting; this protects the bacteria
4.
Leukoeidins -these are proteins that damage membranes of white blood cells; they allow bacteria to survive.

question

name two types of toxic substances

answer

exotoxins
endotoxins

question

define exotoxin

answer

proteins, secreted from the bacterial cell; they bind to certain body sites and cause damage (symptom);

question

name three examples of exotoxins

answer

1.Tetanospasmin from Clostridium tetani 2.Botulinum toxin from Clostridium
3.Diphtheria toxin -from Corynebacterium diphtheriaea

question

these are lipopolysaccharide (LPS) molecules present in the outer membrane of all Gram negative bacteria; these cause

answer

endotoxins

question

a.Fever
b.chills
c.weakness
d.aches
e.activation of complement
f. activation of the clotting of blood g.damage to blood vessels which causes release of fluids with resultant loss of blood pressure
h.Damage to internal organs may result due to lack of blood flow
i. Endotoxins arc not destroyed with heat

answer

these are things that endotoxins cause or are characteristic of.

question

what three characteristics is aquired immunity defined by?

answer

1.displays specificity
2.displays memory
3.recognizes self from non-self

question

the body remembers being exposed to a certain infection, this is....

answer

memory

question

Humoral immunity is also known as

answer

antibody mediated immunity

question

what are the two forms of aquired immunity?

answer

Humoral immunity (HI) and cell mediated immunity (CMI)

question

what is humoral immunity mediated by?

answer

antibodies

question

proteins produced by an individual in response to an antigen and the ________ molecules physically combine with the same antigen molecules that induced their formation

answer

Antibodies

question

antibodies are:

answer

Proteins of molecular weights of 160,000 to 900,000
2. They are found in body fluids

question

what body fluids are antibodies found?

answer

a. Blood gamma globulin fraction of serum/plasma
b. Lymph
c. Mucous secretions
d. Other internal body fluids

question

electrophoresis

answer

a technique used to isolate antibodies from serum

question

what body fluids are antibodies found?

answer

a. Blood gamma globulin fraction of serum/plasma
b. Lymph
c. Mucous secretions
d. Other internal body fluids

question

the process used to isolate antibodies from serum

answer

electrophoresis

question

_______s (Ag) are molecules that induce antibody formation; the _______ physically combine with the antibodies they induced;

answer

antigens

question

1. Proteins, polysaccharides, and, sometimes, lipids or nucleic acids
2.They must be larger than 10,000 Daltons (molecular weight)
3.They are usually foreign to the individual; they may be part of an infectious agent

answer

antigens are:

question

small bumps on the surface of an antigen are called ______

answer

antigenic determinants (epitopes)

question

Antibody molecules physically combine with these _____ by forming weak bonds

answer

antigenic determinants (epitopes

question

describe the structure of an antibody

answer

. They are proteins composed of two identical polypeptides (they have the same amino acid sequence) called heavy; chains and two identical, but shorter polypeptides called light chains; these are covalently linked together.
2.The large protein molecule folds producing a Y shaped protein that has two arms.
3.The ends of the two arms are the portions that physically combines with the antigenic determinant

question

Name the five classes of antibody molecules.

answer

1.Immunoglobulin G (IgG) .. highest concentration in blood
2.IgM largest; next highest in concentration
•3.IgA .. found in mucous secretions (secretnry immunoglobulin)
4.IgD -unknown function
5.IgE .. lowest concentration; responsible for allergies

question

highest concentration in blood

answer

Immunoglobulin G (IgG)

question

lowest concentration; responsible for allergies

answer

IgE

question

largest; next highest in concentration

answer

IgM

question

found in mucous secretions (secretory immunoglobulin

answer

IgA

question

antibody molecule unknown function

answer

IgD

question

how do antibodies show specificity?

answer

1. An antibody reacts (forms weak bonds) only with the same antigen that induced its formation
2. This is due to complementary shapes of the antigen combining site and the antigenic determinant

question

Origin of immunoglobulins

answer

1.They are produced by cells derived from stem cells of the bone marrow.
2.Each mature B-cell acquires a unique Ab molecule on its surface; each specific for a different antigenic determinant.
3.Exposure to antigen (antigenic determinant) induces immune response, i.c. production of antibody

question

two types of lymphocytes

answer

(1) B-cells; these mature in bone marrow and are responsible for humoral immunity
2.T-cells; these migrate to/and mature in the thymus; they are responsible for cell-mediated immunity

question

J. On re-exposure to the same antigen, the immune response occurs more quickly and produces more Ab
2. This is due to many, memory cells
3. This is the basis for memory; the secondary immune response is quicker and more intense. these three things describe the ______ immune response

answer

Anamnestic (memory) immune response

question

describe the Precipitation (precipitation) tests

answer

(1)
The antigen is soluble (a molecule); its solution is clear
(2)Ab-Ag complex produces a visible precipitate

question

(1) The antigen is particulate, e.g. bacterial cells or large particles; its suspension is usually cloudy
(2)Particulate antigen forms visible clumps.
This describes which serologic test?

answer

Agglutination test

question

describe the Enzyme-linked immunosorbent assay (ELISA) tests

answer

(1) Antigen is absorbed to a surface
(2)A human antibody (serum) is added
(3)Human antibody is detected by the use of an enzyme linked to an antibody specific to the human antibody

question

(1)A fluorescent chemical is linked to an antibody
(2)The antigen is detected by fluoresence microscopy.
These describe which serologic test?

answer

fluorescent antibody

question

To detect Ab (produced by infection) a known Ag must be used in the test
to detect Ag (a molecule from an agent causing infection) a known must be used in the test.

answer

these are characteristics of serologic tests used to diagnose disease

question

define Antibody titer

answer

a. this is a measure of the amount of Ab an individual has in serum.
b. The titer may indicate the stage of or the severity of disease in an individual

question

name four examples of how antibodies protect against infectious disease

answer

1. neutralize exotoxins
2. attach to extracellular parasites; this may facilitate their phagocytosis and killing by white blood cells; this is called opsonization.
3,Antibodies may attach to viruses and prevent their attachment and entrance into host cells; this is called virus neutralization
4.Complexes of antigen and antibody may activate complement
a. This stimulates the classical pathway of complement activation

question

(1)Increased inflammation
(2)Increased phagocytosis and
(3)Membrane damage to the infectiousagent.
These describe_________

answer

the activation of complement

question

define opsonization

answer

Antibodies may attach to extracellular parasites; this may facilitate their phagocytosis and killing by white blood cells

question

a.Acquired in an individual by surviving an infection
b.Is a natural process
c.The individual (infected person) produces the immunity (active immunity)
d.Immunity is long lived; memory cells are present.
Which type of immunity does this describe?

answer

Active, natural immunity

question

Describe passive, natural immunity

answer

a.Immunity of newborn infant
B.Is a natural process.
C. The child recieves immunity made by its mother (passive immunity)
d.Mediated by IgG that has crossed the placenta
c.Immunity is short lived; the child has no memory cells

question

a.Acquired in an individual by immunization
b.Is not a natural process; is artificial
c.The individual who is immunized makes the antibodies
d.Immunity is long lived: memory cells are present
e.Vaccines
These are characteristics of what type of immunity?

answer

Active, artificial immunity

question

Vaccines may be:

answer

(1)Killed cell or inactivated virus
(2)Component(s) of bacterial cells or virus
(3)Toxoids (denatured exotoxins; not toxic, but immunogenic)
(4)Attenuated bacterial cell or virus; these are alive but are altered and unable to cause disease

question

a.Aquired after administration of gamma globulin (immune globulin) isolated from human donors
b.Is not a natural process; is artificial.
These are two of four characteristics of which type of immunity?

answer

Passive, artificial immunity

question

name the 4 characteristics of passive, artificial immunity

answer

a.Aquired after administration of gamma globulin (immune globulin) isolated from human donors
b.Is not a natural process; is artificial
c.Antibodies are made by donors; individual receives only antibodies;
d.Immunity is short lived; memory cells are not present No memory cells present immunity is short lived

question

c.
Antibodies arc made by donors; individual receives only antibodies;
d.
Immunity is short lived; memory cells are not present No memory cells present immunity is short lived. these tho characteristics come from what type of immunity?

answer

passive artificial immunity

question

T-cells are lymphocytes that

answer

1.Mature in the thymus
2.Have T-cell receptor molecules on their surface.
3.On exposure to antigen (during infection) the above cells react to protect host

question

T-cell receptors are composed of two

answer

nonidentical polypeptide chains, each having constant and variable regions

question

When nonidentical polypeptide chains, each having constant and variable regions react with antigen of an infectious agent: this triggers T-cells to multiply forming________

answer

(l)Helper T-cells
(2) Cytotoxic T-cells
(3)Memory T-cells

question

(l)
These secrete Iymphokines, small polypeptides; these
(a)
Induce inflammation causing macro phages to migrate into the area
(b)
Activate macrophages enhancing their metabolism so they can kill intracellular microorganisms
(2) These cells also have an effect on antibody formation by B-cells. this describes. ______ T-cells

answer

helper

question

these react with antigen on infected cells causing their destruction

answer

Cytotoxic T-cells

question

Memory cells act like the original _____

answer

T-cell

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