Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
170 Cards in this Set
- Front
- Back
pathology
|
study of disease
|
|
etiology
|
cause of disease
|
|
pathogenesis
|
manner in which disease develops
|
|
infection
|
invasion or colonization of the body by pathogenic mircobes
|
|
disease
|
any change from a state of health
abnormal state in which all or part of body isn't adjusted or is incapable of performing its normal functions = occur without detectable disease |
|
normal flora
|
organisms in or on the body that do not cause disease under normal conditions
certain locations in and on the body normally have microbial populations; other sites wont ( sterile) |
|
transient flora
|
not permanent residents but may be present for several days, weeks, or months and then disappear
|
|
skin
|
restrict the growth of microorganisms
ex = Staphylococcus sp. S. aurues and S epidermidis Corynebacterium sp Proprionibacterium sp Micrococcus sp Candida sp |
|
Eye ( conjunctiva)
|
continuation of skin and mucous membranes, therefore, will have similar organism
ex = S. epidermidis and S aureus Corynebacterium sp Proprionibacterium sp Streptococcus sp Micrococcus |
|
nose and throat
nose |
S. aureus
S. epidermidis diptheroids |
|
nose and throat
throat |
S. aureus
S. epidermidis Dipotheroids Streptococcus pneumoniae Haemophilus sp Neisseria sp. |
|
mouth
normal flora |
Streptococcus sp
Lactobacillus Neisseria sp Haemophilus sp Staphylococcus sp Anareobes : Fusobacterium sp. Veillonella sp |
|
large intestine
|
coliforms : Escherichia coli
Citrobacter sp Lactobacillus sp Proteus sp Klebsiella sp Enterobacter sp Enterococcus sp Anaerobes : Fusobacterium sp |
|
Genito-urinary systems
all mucous membranes having contact with outside (continuation of the skin) will have normal flora lower urethra of male and female vagina |
normal flora include: Skin organisms
Lactobacillus sp Candida Sp |
|
sterile sites
|
heart
liver spleen blood system lymphatic system all internal organs |
|
microbial antagonism
|
microbial antagonism/competitive exclusion
competition among microbes normal flora protect host against pathogens by: competing for nutrients producing harmful substances affecting conditions such as pH and oxygen |
|
symbiosis
|
relationship of 2 different organisms that live together
|
|
commensalism
|
one organism is benefitted, the other is unaffected
|
|
mutualism
|
both organisms are benefitted
|
|
parasitism
|
one organisms is benefitted and the other is harmed
|
|
opportunistic organisms
|
DO NOT cause disease in the healthy host
DOES cause disease in the immunocompromised |
|
classification of disease
|
1. occurrence of a disease
2. severity or duration of disease 3. extent of host involvement 4. symptoms : subjective changes in the body function, as evidenced by patient 5. signs : objective, measurable changes, as evidenced by observer |
|
communicable disease
|
disease that spreads from on host to another (either directly or indirectly)
contagious : spreads easily non-communicable : infectious diseases that don't spread from person to person contracted from environment or ourselves |
|
occurrence of disease
1. incidence 2. prevalence |
1. number of people in a population who develop a disease during a particular period of time (new cases)
2. the number of people who have a particular disease at a specified period of time ( new and old cases) |
|
sporadic
|
occasional occurrence
|
|
endemic
|
occurs constantly in a population
|
|
epidemic
|
an increase in the incidence of a particular disease above the numbers normally seen
|
|
pandemic
|
am epidemic that occurs worldwide or across continents
|
|
acute disease
|
develops rapidly but lasts only a short time
|
|
chronic
|
develops more slowly, may be less severe, but is continuous or recurrent for a long time
|
|
subacute
|
intermediate to acute and chronic
|
|
latent
|
causative agent remains inactive for a long period of time and then reactivates and produces s/s
|
|
herd immunity
|
percent of population who are immune to a particular disease... if immune can't spread, can't get disease, can't spread disease to others...
|
|
local infection
|
limited to a small area of the body
|
|
systemic infection
|
organisms are spread throughout the body by the blood or lymphs
|
|
focal infection
|
a local infection is spread to a specific area and are combined there
|
|
septicemia
|
systemic infection due to organisms reproducing in the blood
|
|
bacteremia
|
presence of bacteria in the blood
|
|
toxemia
|
presence of toxins in the blood
|
|
viremia
|
presence of viruses in the blood
|
|
primary infection
|
an acute infection that causes the initial illness
|
|
secondary infection
|
a second organism causes an illness due to the host's weakened condition because of the primary infection
|
|
subclinical infection
|
infection in which no noticeable illness is seen
|
|
predisposing factors
|
gender
race geographic location nutritional status age occupation immune status |
|
development of disease
|
incubation period
prodromal period period of illness period of decline period of convalescence |
|
incubation period
|
time from initial exposure until first appearance of s/s
dependent on: organism virulence/pathogenicity resistance of host |
|
prodromal period
|
doesn't occur in all diseases
occurs relatively short time mild symptoms of general aches and malaise ( tiredness) |
|
period of illness
|
period of time when the disease is most severe
pt exhibits s/s one of 2 things happen: treatment is successful and pt recovers or isn't and pt dies |
|
period of decline
|
s/s subside
pt begins to recover this is the time in which pts are vulnerable to 2nd infections |
|
period of convalescence
|
pt regains strength and body returns to the pre-diseased state
not necessarily healthy |
|
reservoirs
|
are sources that provide the organism with adequate conditions for survival, multiplication, and an opportunity for transmission
can be: human, animal, non-living |
|
human reservoirs
|
transmitted from person to person:
current active disease : s/s present incubation or recovery : s/s not present during a carrier state transmitted directly or indirectly |
|
animal reservoirs
|
disease occur primarily in animals (wild or domestic) and can be transmitted to people are called zoonoses
occur by many routes: direct contact with infected animals contact with waste products of animals contamination of food and/or water insect vectors |
|
non-living reservoirs
|
soil harbors- fungi/bacterial spores
water can be contaminated with feces of humans or other animals |
|
contact transmission
|
direct
indirect droplet |
|
vehicle transmission
|
water
food air |
|
vectors
|
mechanical transmission
biological transmission |
|
emerging infectious disease
|
new or changing
showing an increase in incidence in the recent past shows the potential to increase in the future ex: Anthrax-bioterrorism Toxigenic E. coli non 0157:H7 Acinetobacter Pandemic influenza |
|
epidemiology
|
studies diseases occurring in populations, not individuals
investigates the underlying reason what intervene or control will prevent the spread of disease |
|
descriptive epidemiology
|
retrospective studies- looking back at what happened
prospective studies- choosing a group of disease and follow them forward to see if and when disease develops |
|
analytical epidemiology
|
case control studies- look for factors that may have preceded the disease and see if cases differ from controls
|
|
experimental epidemiology
|
clinical trails
|
|
pathogenicity
|
the ability of a microorganisms to cause disease by overcoming the defenses of a host
|
|
virulence
|
the degree or extent of pathogenicity
|
|
portals of entry
|
3 primary routes of entry (or portals of entry)
mucous membranes skin parenteral portal of entry and exit are often the same |
|
mucous membranes
|
enter thru mucous membranes of resp tract or GI tract
esp if mucous membranes are damaged EX : resp = influenza, TB, common cold GI = polio, Hep. A, Shigella GU = STDs- chlamydia, gonorrhea, syphilis |
|
skin
|
unbroken skin is impenetrable to most microorganisms
some microbes have adapted to penetrate = syphillis hookworm larvae broken skin or routes thru hair follicles and sweat gland ducts are common routes some fungi actually infect the hair, skin or nails |
|
parenteral routes
|
directly deposited into tissues beneath skin or mucous membranes
punctures (incl needlesticks), inj., bites, cuts, wounds, surgery, etc. ex= tetanus, gangrene, Hep B&C and HIV via sticks |
|
infectious dose
|
number of organisms needed to cause disease
chance of disease occurring is dependent on the number of microbe the host is exposed to dependent on microbe and virulence of pathogen |
|
attachment
|
adherence or adhesion is required in pathogenicity
|
|
adhesins or ligands
|
on the pathogen bind to complementary receptors on the host's cell surface
|
|
pathogens penetrate host defenses
aka virulence factors |
capsules
cell wall components enzymes antigenic variation penetration into the cytoskeleton |
|
capsules
|
impair phagocytosis- ability of certain host cells to engulf and destroy microbes
ex : Streptococcus pneumoniae Klebsiella pneumoniae Haemophilus influenzae Bacillus anthracis |
|
cell wall components
|
chemical substances in the cell wall which contribute to virulence
ex = Streptococcus pyogenes- M protein that mediates attachment to host epithelial cells and helps resist phagocytosis Mycobacterium tuberculosis - waxy substance in the cell wall that resists digestion by phagocytes |
|
enzymes
coagulases |
clot production, walls off the bacteria and prevents phagocytosis and isolates the microbe from other host defenses
|
|
enzymes
kinases |
break down clots , and allow invasion into the tissues
|
|
enzymes
collagenase |
breaks down collagen, allowing spread of the organisms
|
|
antigenic variation
|
ability of an organism to alter surface antigens so that antibodies against that organism are no longer effective
ex = influenza virus Neisseria gonorrhoeae |
|
penetration of the cytoskeleton
|
penetration into the host cell or the ability to move through and between host cells
|
|
exotoxins
|
produced within bacteria and secreted to the outside
( most often Gram + organisms) 1.easily diffused into blood and rapidly transported 2.harmful in small amounts 3.function by destroying host's cells or inhibiting metabolic functions 4. diseases caused by exotoxins are caused by toxins not the bacteria 5. disease-specific s/s 6. body produces antibodies to toxins = anitoxins |
|
exotoxins
botulism |
neurotoxin- prevents transmission of nerve impulses resulting in flaccid paralysis
|
|
exotoxin
tetanus |
neurotoxin- blocks nerve impulses to muscle relaxation resulting in uncontrollable muscle contractions
|
|
exotoxin
staph food poisoning |
enterotoxin- secretion of fluids and electrolytes resulting in diarrhea
|
|
exotoxin
diphtheria |
cytotoxin- inhibits protein synthesis
|
|
endotoxins
|
part of the outer cell walls of gram - bacteria
released when gram - bacteria die, lysing cell walls, releasing endotoxin work by stimulating macrophages to release cytokines which are toxic at high levels endotoxins do not promote effective antitoxin formation produce the same s/s regardless of the microbe |
|
endotoxins
|
s/s : chills, fever, weakness, generalized aches, sometimes shock and death
can also activate blood clotting proteins resulting in DIC ( disseminated intravascular coagulation) |
|
endotoxins
shock |
shock = any life-threatening decrease in blood pressure
|
|
endotoxins
septic shock |
caused by bacteria
|
|
endotoxins
endotoxins shock |
caused by gram - bacteria
|
|
portals of exit
|
microbes leave the body via SPECIFIC ROUTES
ex: secretions, excretions, discharges or tissues that have been shed are related to infected part of body most common are resp and GI, but also GU, skin, and wound infections, and blood |
|
Immunity
|
ability to ward off disease caused by microbes or their products and to protect against environmental agents
|
|
immunity defenses designed to :
|
keep microorganisms out
remove microbes if they do get in combat them if they remain inside |
|
susceptibility
|
lack of immunity
|
|
nonspecific or innate immunity
|
defenses present at birth
always present respond rapidly to protect against disease acts against all microbes in same way does not involve specific recognition or memory |
|
lines of defense
|
1. skin and mucous membrane
2. phagocytosis, inflammation, fever, and other antimicrobial substances or cells 3. specialized cells and antibody production |
|
defense
skin and mucous membrane |
physical factors : barriers to entry or processes that remove microbes
chemical factors : substances made by the body that inhibit microbial growth or that destroy microbes |
|
chemical
sebum |
an oily substance produced in the sebaceous gland
prevents hair from drying protective film on the skin one of its components are fatty acids which keep pH of skin low (3-5) |
|
chemical factors
perspiration |
produced by sweat glands
helps maintain body temp eliminates certain wastes flushes microbes from surface the skin contains lysozyme- an enzyme that can break down bacterial cell walls |
|
chemical factors
gastric juices |
produced by glands in stomach
consists of HCL, enzymes and mucus very high acidity (pH 1.2-3) destroys bacteria and most bacterial toxins |
|
phagocytosis
|
blood
formed elements : erythrocytes, leukocytes, thrombocytes liquid components: serum w/o clotting factors plasma with clotting factors |
|
leukocytosis
|
increase in WBC
|
|
leukopenia
|
decrease in WBC
|
|
granulocytes
|
presence of granules in the cytoplasma
neutrophils are phagocytes |
|
monocytes
|
become macrophages after leaving circulating blood (into tissues). are phagocytes
|
|
lymphocytes
|
active in specific immunity
|
|
phagocytes
|
cells that can ingest microbes
are activated by components in or on the bacteria |
|
mechanism of phagocytosis
|
1. chemotaxis
2. adherence 3. ingestion a. formation of phagosome 4. digestion a. fusion with lysosome to form phagolysosome b. residual body of indigestible materials 5. discharge of waste materials |
|
inflammation
|
tissue damage that triggers this defensive response
causes: microbial infection, heat, electricity, sharp objects or chemicals 4 signs: redness, pain, heat, and swelling loss of function depending on site and extent of damage |
|
functions of inflammation
|
1.to destroy the agent and remove by-products from the body
2. if destruction is not possible : limit the effects by confining or walling it off 3. repair or replace tissue damaged |
|
stages of inflammation
|
1. vasodilation and increased permeablility of blood vessels
2. phagocytic migration and phagocytosis 3. tissue repair |
|
fever
|
elevated high body temp produced in response to a bacterial or viral infection
1. fever is considered a defense against disease speeds up body's reactions complications : dehydration, seizures, acidosis |
|
complement system
|
causes cytolysis of microbes, promotes phagocytosis, contributes to inflammation
|
|
interferons
|
protects uninfected cells from viral infections
|
|
transferrins
|
inhibit growth of bacteria by reducing available iron
|
|
antimicrobial peptides
|
cause lysis of bacteria
|
|
natural killer cells
|
kill infected targets cells which are then phagocytized
|
|
adaptive or acquired immunity
|
develops during an individual's lifetime
3 important components : 1. specificity 2. memory 3. recognition ANTIbody Generators |
|
adaptive immunity
active |
body produces antibody in response to an antigen
takes longer to develop, persists longer, involves memory |
|
adaptive immunity
passive |
body receives pre-formed antibody from another source
immediately available, short duration, no memory involved |
|
adaptive immunity
natural |
born with
|
|
adaptive immunity
artificial |
man-made/produced
|
|
natural
active |
immunity produced in response to exposure and subsequent recovery from a disease
|
|
natural
passive |
immunity produced from antibody transfer from Mom to offspring across the placenta or thru breast milk
|
|
artificial
active |
immunity produced in response to injection of man-made antigen (vaccine)
|
|
artificial
passive |
immunity produced in response to injection of preformed antibodies (immunglobuline or Ig)
|
|
antigens (Ag)
|
proteins that provoke a response like mircoorganisms
( ANTIbody GENerators) |
|
antibodies (Ab)
|
proteins made in response to the antigen
these proteins are made by the immune system |
|
antigens
|
proteins or large polysaccharides
1. can be components of invading microbes- like capsules, cell walls, flagella, fimbriae, toxins 2. antibodies interact and recognize specific regions on the Ag called epitopes or antigenic determinants |
|
antibodies
|
made in response to the SPECIFIC ANTIGEN
1. are globular proteins called IMMUNOGLOBULINS 2. have unique structure allowing them to bind to the antigenic determinants on the antigen 3.HELP TO NEUTRALIZE OR DESTROY THE AG |
|
5 classes of immunoglobulins
|
IgG
IgM IgA IgE IgD |
|
IgG
|
80% of Ab in serum
has ability cross placenta functions: 1. enhances phagocytosis 2. neutralizes viruses and toxins 3. protects fetus and newborn |
|
IgM
|
5-10% of Ab in serum
pentamer- 5 monomers to large to cross the placenta and generally stays in blood vessels FIRST Ab produced in response to an Ag relatively short-lived |
|
IgA
|
1.relatively small amount in serum but most common Ig in mucous membranes and body secretions
2. dimer structure 3. functions as localized protection on mucosal surfaces |
|
IgD
|
1.monomer structure
2.very small amt in serum 3.found on the surface of B lymphs 4.functions in initiation of the immune response |
|
IgE
|
1.monomer structure
2.very,very small amount in serum 3.bind to mast cells and basophils involved in allergic reactions |
|
Ag-Ab complexes and their results
|
1.binding of an antibody to an antigen protects the host by tagging "foreign" cells and molecule for destruction by phagocytes and complement
2.mechanisms include: 1.agglutination 2. opsonization 3. neutralization 4. Ab-dependent cell-mediated sytotoxicity 5. activation complement leading to inflammation and cell lysis |
|
immunological memory
|
original exposure to an antigen has a lag time
process of immunity creates MEMORY CELLS second exposure to an antigen, the memory cells are reactivated and respond very quickly- becoming protective quickly |
|
primary response
|
Primary
IgM slow onset low magnitude short-lived |
|
secondary response
|
secondary
IgG ( or IgA or IgE) rapid onset high magnitude long-lived |
|
active disease
|
presence of IG
|
|
titer
|
measure the amount of antibody present
|
|
humoral immunity-antibody mediated
|
B lymphocytes produce antibody
present in serum and lymph |
|
cellular immunity-cell mediated
|
T lymphocytes
present in tissues |
|
humoral immunity
B cells or B lymphocytes |
lymphs that have matured in the bone marrow
recognize free or extracellular antigens and make antibody |
|
process of humoral immunity
|
1. B cells binds the antigen and becomes activated
2. activated B cells undergo clonal expansion or proliferation ( all of these cells are identical) 3. some of these cells differentiate into plasma cells which produce antibody 4. some of these cells become long-lived memory cells |
|
cellular immunity
|
1.T cells or T lymphocytes mature under the influence of the thymus
2. they respond to antigens and secrete cytokines cytokines are chemical messengers that tell other cells what to do 3. T cells respond to intracellular organisms-viruses, bacteria, parasites |
|
process of cellular immunity
|
1. the helper T cells is activated when the antigen is present
2.activated helper T cells 1.proliferate and secrete cytokines that activate macrophages, enhancing phagocytic activity 2.secrete cytokines that activate cytotoxic cells into cytotoxic T lymphocytes (CTLs) 3. produce cytokines that activate B cells 4. memory cells are also produced |
|
specificity of antibodies
|
using knowledge of immunology and to antigens, we apply it to 2 situations
vaccines diagnostic tests |
|
vaccines
natural active |
immunity produced in response to exposure and subsequent recovery from a disease
|
|
vaccines
natural passive |
immunity produced from antibody transfer from mom to offspring across the placenta or thru breast milk
|
|
vaccines
artificial active |
immunity produced in response to injection of a man-made antigen (vaccine)
|
|
vaccines
artificial passive |
immunity produced in response to injection of preformed antibodies (Immunoglobulin or Ig)
|
|
principle of vaccination
|
to provoke the primary immune response
when exposed to the organism again the response willl be: 1.rapid 2. effective and 3. prevent the development of disease |
|
disease prevention
|
ways to prevent disease transmission:
1.sanitation 2.control of vector 3.isolation and quarantine 4.vaccines an effective VACCINE is the best method of disease control |
|
types of vaccines
|
attenuated whole-agent vaccines
inactivated whole-agent vaccines toxoids subunit vaccines conjugated vaccines nucleic acid vaccines |
|
attenuated whole-great vaccines
|
use living-but attenuated (weakened) microbes
1. most closely mimic actual infection 2. lifelong immunity 3. effectiveness of 95% 4. ex= MMR, oral polio vaccine (Sabin) |
|
inactivated whole-great vaccines
|
use microbes that have been killed- usually by formalin or phenol
ex = influenza vaccine injectible polio vaccine (Salk) pneumococcal polysaccharide vaccine (Pneumovax) |
|
toxoids
|
inactivated toxins
1. are directed at the toxins produced by a pathogen 2. ex = diptheria and tetanus toxoids 3. required series of vaccines and boosters |
|
subunit vaccines
|
use only antigenic fragments that stimulate the immune system
1. fragments can NEVER reproduce in host 2. contain little extra material-fewer side effects 3. ex = Hepatitis B vaccine |
|
conjugated vaccines
|
developed due to POOR IMMUNE RESPONSE in young children
1. polysaccharides are attached to proteins which the child's system can recognize and respond to ex = pneumococcal conjugate vaccine, HiB (Haemophilus influenza type B) |
|
diagnostic Immunology
|
2 critical components of a diagnostic test are :
1.sensitivity- test is positive when a person has the disease 2. specificity- test is negative when a person doesn't have the disease |
|
monoclonal antibodies
|
used in diagnostic tests because they :
are uniform are highly specific can be produced in large quantities |
|
precipitation reactions
|
1. involve the reaction of soluble antigens with either IgM or IgG antibodies to form large, interlocking lattices (visible)
2. occur only when the ratio of antigen to antibody is optimal |
|
agglutination reactions
|
agglutination reactions involve either particulate antigens (such as cells) or antigens adhering to particles
these antigens can be linked together by antibodies to form visible CLUMPS |
|
titers
|
the amt of Ab present in the serum
1.seroconversion= before illness no antibody present; during illness detectable antibody 2.rise in titer= during the acute phase of disease, antibody was present, during the convalescent period the amt of antibody was elevated samples taken 2 weeks apart significant rise= fourfold increase |
|
complement fixation
|
during most Ag-Ab reactions, complement binds to the complex and is used up or fixed
complement fixation is used to detect very small amts of Ab |
|
direct FA test
|
used for clinical specimens
ex= virus isolation |
|
indirect FA test
|
detects specific antibody in serum following exposure
|
|
Indirect ELISA
|
detects antibody
|
|
Direct ELISA
|
detects antigen
|