Exam 3 material Flashcards
(240 cards)
1
Q
human microbiome
A
sum total of all microbes found on and in normal humans
critically important to the health and functioning of its host organisms
2
Q
infection
A
microbes get past host defenses, enter tissues, and multiply
3
Q
disease
A
deviation from health that results when cumulative effects of infection damage or disrupt tissues and organs
4
Q
infectious disease
A
a pathologic state caused directly by miroorganisms or their products
5
Q
what is the human microbiome project?
A
worldwide research efforts to characterize microbes living on human bodies when healthy
determine how the microbiome differs on various diseases
utilizes powerful techniques of genome sequencing and big data tools
6
Q
how many protein-encoding genes are there in human cells
A
21,000
7
Q
are microbes found in sterile environments?
A
yes
8
Q
how many viruses are found in human feces
A
100 million
9
Q
what sites typically harbor normal microbiota
A
skin and adjacent mucuos membranes, upper respiratory tract, gastrointestinal tract, outer portion of urethra, external genitalia, vagina, external ear canal, external eye
10
Q
what factors weaken host defenses and increase susceptibility to infection
A
old age and extreme youth(infancy and prematurity)
genetic defects in immunity and acquired defects in immunity
surgery and organ transplants
underlying disease: cancer, liver malfunction, diabetes
chemotherapy/immunosuppressive drugs
physical and mental stress
pregnancy
other infections
11
Q
where do newborns get important microbiota
A
through its trip through the vagina
-lactobacillus provides the baby with the necessary enzymes to digest milk\
12
Q
what are some disorders attributed to disruption of gut microbiome
A
inflammatory bowel disease, obesity
13
Q
inflammatory bowel disease
A
chronic inflammation of the gut and disruption of homeostasis, an impaired microbiome(dysbiosis)
ulcers or sores form on superficial lining of large intestine and rectum
also called Crohn’s disease
14
Q
dysbiosis
A
when normal colon microbiome is impaired, not in homeostasis
ex: clostridioides difficile infection(CDI)
strict anaerobic, gram-positive
15
Q
antibiotic-associated colitis
A
primary result of antibioitic treatment for some other infection and ingestion of spores
antibiotics can drastically affect normal microbiome of colon
C.diff is allowed to proliferate, releasing toxins that attack the mucosa of the colon, causing epithelial necrosis in the colon
16
Q
pseudomembranous colitis
A
inflammatory cells, dead cells, necrotic tissue, and fibrin that obstructs the intestine
cramping, water diarrhea, can result in death
17
Q
microbiological factors affecting C.difficle infection and recurrence
A
microbiota(healthy microbiota inhibits to C.difficle spore colonization, but once microbiota populations are disrupted C.diff infection can occur)
c. difficle spore variability(disrupted microbiota will not lead to CDI unless spores are present in gut)
18
Q
fecal microbial transplants
A
treatment: very potent drugs, relapse occurs
fecal transplant
combat bacterial infection of colon by infusing the colon with feces from a healthy person to displace the pathogenic c. difficle, restoring the normal balance in the colon
19
Q
reservoirs for c. difficle
A
likely that colonized patients serve as reservoirs for c. difficle in health care settings
domestic animals(cattle, horses, dogs, cats, etc)
food supply(meat)
20
Q
pathogen
A
a microbe whose relationship with its host is parasitic and results in infection and disease
21
Q
pathogenicity
A
an organism’s potential to cause disease
22
Q
true pathogens(primary pathogens)
A
capable of causing disease in healthy persons with normal immune defenses
have well developed virulence properties
generally associated with specific disease
23
Q
opportunistic pathogens
A
cause disease when the host’s defenses are compromised or when the pathogens become established in a part of the body that is not natural to them
not pathogenic to normal, healthy people
24
Q
virulence
A
relative severity of a disease caused by a particular microbe
degree of pathogenicity
25
what is the virulence of a microbe determined by
its ability to establish itself in a host
enter host, attach firmly to host tissues, negotiate the microbiome, and survive host defenses
cause damage
produce toxins that damage host tissues or induce a host response that actually harms or damages the host tissues or cells
26
virulence factor
any characteristic or structure of the microbe that contributes to its ability to establish itself in the host and cause disease
27
what does influenza(viral infection) frequently lead to
pneumonia(often a bacterial infection)
28
what tracts are involved in finding a portal of entry
skin, GI tract, respiratory tract, urogenital tract, endogenous biota
29
what parts are involved in attaching firmly and negotiating the microbiome
fimbrae, capsules, surface proteins, and viral spikes
30
what parts are involved in surviving host defenses
avoiding phagocytosis, avoiding death inside phagocyte, absence of specific immunity
31
what parts are involved in the portal of exits
respiratory tract, salivary glands, skin cells, fecal matter, urogenital tract, blood
32
portal of entry
route that a microbe takes to enter the tissues of the body to initiate an infection
33
exogenous
microbe originating from a source outside the body from the environment or another person or animal
34
endogenous
microbe already existing on or in the body-normal biota or a previously silent infection
35
what does mycobacterium tuberculosis travel through
both the respiratory and gastrointestinal tract
36
what do streptococcus and staphylococcus enter through
through the skin, urogenital tract, and the respiratory tract
37
infectious dose
minimum number of microbes necessary to cause an infection to proceed
38
phagocytes
cells that engluf and destroy host pathogens by means of enzymes and antimicrobial chemicals
39
antiphagocytic factors
virulence factors used by some pathogens to avoid phagocytosis by phagocytes
40
leukocidins
cytotoxin that kill phagocytes outright
produced by streptococcus and staphylococcus
41
exoenzymes
enzymes secreted by microbes that break down and inflict damage on tissues
dissolve the host's defense barriers to promote the spread of disease to other tissues
42
mucinase
digests the protective coating on mucous membranes
major factor in amoebic dysentery
43
hyaluronidase
digests the ground substance that cements animal cells together
44
coagulase
causes clotting of blood or plasma
45
kinase
dissolves fibrin clots
46
toxins
a specific chemical product of microbes that is poisonous to other organisms
47
neurotoxins
act on nervous system
48
enterotoxins
act on intestine
49
hemotoxin
lyse red blood cells
50
nephrotoxins
damage the kidneys
51
sign
objective evidence of disease as noted by an observer
52
symptom
subjective evidence of disease as sensed by the patient
53
syndrome
a disease identified by a certain complex of signs and symptoms
54
signs of inflammation
edema(swelling), granulomas and abscesses, lymphadenitis
55
edema
the accumulation of fluid in afflicted tissue
56
granulomas and abscesses
walled-off collections of inflammatory cells and microbes in the tissues
57
lymphadenitis
swollen lymph nodes
58
symptoms of inflammation
fever, pain, soreness, swelling
59
signs of infection in the blood
septicemia
60
septicemia
a general state in which microorganisms are multiplying in the blood and are present in large numbers
61
why do infections go unnoticed
no noticeable symptoms are produced
microbe is active in host tissues
host does not seek medical attention
asymptomatic
62
what are the major portals of exit
coughing/sneezing, insect bite, removal of blood, feces, urine, skin cells and lesions
63
incubation period
time from initial contact with the infectious agent to the appearance of symptoms
agent is multiplying but has not caused enough damage to elicit symptoms
64
prodromal stage
1-2 day period when the earliest notable symptoms of infections appear
vague feelings of discomfort: head and muscle aches, fatigue, upset stomach, general malaise
65
acute stage
infectious agent multiplying at high levels, exhibits its greatest virulence, becomes well established in its target tissue
66
convalescent period
patient begins to respond to infection and symptoms decline
patients health and strength gradually return due to healing nature of immune response
67
reservoir
primary habitat in natural world from which a pathogen originates
68
transmitter
individual of object from which an infection is acquired
69
syphilis
reservoir and transmitter are the same
70
carrier
an individual who inconspicuously shelters a pathogen, spreads it to others without any notice
71
what is the typical reservoir of animals
arthropods such as fleas, mosquitoes, flies, and ticks
larger animals:mammals=rabies, birds=psittacosis, lizards=salmonellosis
72
zoonosis
an infection indigenous to animals but naturally transmissible to humans
close association between animals and humans
73
communicable
a disease in which an infected host can transmit the infectious agent to another host and establish infection in the host
74
contagious
disease that is highly communicable, especially through direct contact
influenza and measles are highly contagious
75
noncommunicable
infectious disease that does not arise through transmission of the infectious agent from host to host
76
vertical transmission
disease transmitted from parent to offspring via ovum, sperm, placenta, milk
77
horizontal transmission
disease is spread through a population from one infected individual to another
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direct contact
close contact between people
79
indirect transmission
an object or substance carriers the agent from one person to another
80
fomite
inanimate object
81
vehicle
natural, nonliving material like air, water, soil, and food
82
vector transmission
arthropods that harbor an infectious agent and transfer it to a human
83
mechanical vector
insect carries microbes to host on its body parts
84
biological vector
insect injects microbes into a host; part of microbe life cycle completed in insect
85
nosocomial infections
infectious diseases acquired or developed during a hospital or health care facility stay
86
what are the factors tied to healthcare-associated infections
compromised patients
collection point for pathogens
lowered defenses permit normal biota to enter the body
infections acquired directly or indirectly from fomites, medical equipment, other patients, medical personnel, visitors, air, and water
87
what are the most common healthcare-associated infections
pneumonia
gastrointestinal illness
urinary tract infections
bloodstream infections
surgical site infections
88
common hospital pathogens
clostridioides difficle
staphylococcus aureus
89
etiologic/causative agent
cause of infection and disease
90
koch's postulates
series of proofs that became the standard for determining causation of infectious disease
91
obligate intracellular parasites
cannot multiply unless they invade a specific host cell and instruct its genetic and metabolic machinery to make and release new viruses
92
properties of viruses
obligate intracellular parasites
ubiquitous in nature and had major impact on development of biological life
ultramicroscopic in size
93
capsid
protein shell that surrounds the nucleic acid
94
nucleocapsid
the capsid together with the nucleic acid
95
naked viruses
only have a nucleocapsid
96
envelope
external covering of a capsid, usually a modified piece of the host's cell membrane
97
spikes
can be found on naked or enveloped viruses
98
virion
a fully formed virus that is able to establish an infection in a host cell
99
capsomeres
identical protein subunits
100
genome
the sum total of the genetic information carried by an organism
101
dna viruses
single-stranded or double-stranded
102
rna viruses
can be double-stranded but most often single-stranded
103
positive-sense rna
ready for immediate translation into proteins
104
negative-sense rna
must be converted before translation can occur
105
segmented
individual genes exist on separate pieces of rna
106
retroviruses
carry their own enzymes to create dna out of their rna
107
what are most human viruses
rna viruses
108
examples of double-stranded dna viruses
variola virus, herpes simplex II
109
examples of single-stranded dna
parvovirus
110
single-stranded(+) sense RNA virus
poliovirus, Sars-Cov-2
111
polymerases
synthesize DNA and RNA
112
replicases
copy RNA
113
reverse transcriptase
synthesizes DNA from RNA
114
multiplication cycles in animal viruses
1. adsorption
2. penetration and uncoating
3. synthesis
4. assembly
5. release
115
host range
the limited range of cells that a virus can infect
116
hepatitis B host range
liver cells of humans
117
poliovirus host range
intestinal and nerve cells of primates
118
rabies host range
various cells of all mammals
119
tropisms
specialties of viruses for certain tissues
120
poliovirus tropism
tropism for tissues of the brain and spinal cord
121
influenza virus tropism
primary tropism for the respiratory tract
122
early phase of dsDNA viruses
viral DNA enters the nucleus, where genes are transcribed into a messenger RNA
RNA transcript moves into the cytoplasm to be translated into viral proteins
123
late phase of dsDNA viruses
parts of the viral genome are transcribed and translated into proteins required to form the capsid and other structures
new viral genomes and capsids are assembled
124
cytopathic effect
virus-induced damage to the cell that alters its microscopic appearance
125
types of CPES
gross changes in shape and size
development of intracellular changes
inclusion bodies
syncytia
126
inclusion bodies
compacted masses of viruses or damaged cell organelles in the nucleus and cytoplasm
127
syncytia
fusion of multiple damaged host cells into single large cells containing multiple nuclei(glant cell)
128
persistent infections
some cells maintain a carrier relationship: cell harbors the virus and is not immediately lysed
can last from a few weeks to the remainder of the host's life
can remain latent in the cytoplasm or incorporate into the DNA of host
129
provirus
viral dna incorporated into the dna of the host
130
measles virus
hidden in the brain causing damage and loss of function
131
chronic latent virus
periodically become reactivated under the influence of various stimuli
132
cancer
a set of diseases known to disturb the normal functioning and properties of the cell
133
oncogenes
normal cellular regulatory genes, when modified these genes code for the gene products that disturb the normal regulatory patterns of cells and can result in the loss of normal properties of cel growth and division resulting in cancer
134
transformation
process of a virus inducing carcinogenesis(change to cancer) in a host cell
135
prion
an abnormal form of a normally occuring brain cell protein called PrPc
136
neuritogenesis
formation of axons and dendrites
137
what is chronic wasting disease
affects many different species of hoofed animals
neurological condition that results in changes of body formation, changes in behavior, etc
is fatal
138
what are some examples of the first line of defense
physical barriers, microbiota barrier, chemical barriers
139
first line of defense
any barrier that blocks invasion at the portal of entry
limits access to the internal tissues of the body
not considered a true response because it does not involve recognition of foreign substances
140
what are some examples of the second line of defense
phagocytosis, inflammation, fever, antimicrobial products
141
second line of defense
internalized system of protective cells and fluids
includes inflammation and phagocytosis
acts rapidly at both the local and systemic levels once the first line of defense has been overcome
142
what are some examples of the third line of defense
B cells, T cells
143
third line of defense
acquired on an individual basis as each foreign substance is encountered by lymphocytes
the reaction with each different microbe produces unique protective substances
provides long-term immunity
144
immunology
study of all feature's of the body's second and third lines of defense
study of the body's response to infectious agents
study of allergies and cancer
145
what is a healthy functioning immune system responsible for
surveillance of the body
recognition of foreign material
destruction of entities deemed to be foreign
146
what function do white blood cells have
constantly move throughout the body, searching for potential pathogen
recognize body cells(self)
differentiate them from any foreign material in the body(nonself)
ABILITY TO EVALUATE MACROMOLECULES AS SELF OR NONSELF IS CENTRAL TO THE FUNCTIONING OF THE IMMUNE SYSTEM
147
antigens
molecules on cell surfaces consist of proteins and/or sugars
148
what is the most common method of destruction
phagocytosis
149
pathogen-associated molecular patterns(PAMPS)
markers that many different kinds of microbes have in common
150
pattern recognition receptors
used by host cells with important roles in the innate immunity of second line of defense
recognize PAMPS
151
what does whole blood consist of
blood cells, plasma, serum
152
blood cells
formed elements suspended in plasma
153
plasma
clear, yellowish fluid
154
serum
essentially the same as plasma, except that it is the clear fluid from clotted blood, used in immune testing and therapy
155
hematopoiesis
production of blood cells
156
stem cells
undifferentiated cells that are the primary precursor of new blood cells maintained the bone marrow
continually produced throughout life of body
157
how does the immune system work as a network?
large, complex, diffuse network of cells and fluids that permeate every organ and tissue
promotes surveillance and recognition processes that help screen the body for harmful substances
158
mononuclear phagocyte system
indirect contact with tissue cells and extracellular fluid
blood and lymphatic capillaries penetrate into these tissues
allow cells and chemicals that originate in the MPS and ECF to diffuse into the body and lyphatics
159
lymphatic system
a compartmentalized network of vessels, cells and specialized accessory organs
transports lymph through an increasingly larger tributary system of vessels and lymph nodes, leading to major vessels that drain back to the circulatory system
160
what are the functions of the lymphatic system
provide a route for the return of extracellular fluid to the circulatory system
acts as a "drainoff" system for the inflammatory response
render surveillance, recognition, and protection against foreign materials through a system of lymphocytes, phagocytes, and antibodies.
161
primary lymphatic organs
sites of immune cell birth and maturation
162
what are the primary lymphatic organs
red bone marrow
thymus
163
secondary lymphatic organs
sites of immune cell activation, residence, and functioning
164
what are the secondary lymphatic organs
lymph nodes
spleen
various lymphoid tissues
165
what occurs in red bone marrow
site of B cell maturation
166
what occurs in the thymus
T cell maturation
167
lymph nodes
small, encapsulated, bean-shaped organs
stationed in clusters along lymphatic channels and large blood vessels of the thoracic and abdominal cavities
168
where are aggregations of lymph nodes found
armpit(axillary nodes)
groin(inguinal nodes)
neck(cervical nodes)
169
spleen
found in upper-left portion of abdominal cavities
serves as a filter for blood instead of lymph
primarily removes worn-out red blood cells
also filters pathogens from the blood for phagocytosis by macrophages
170
associated lymphoid tissues
skin-associated lymphoid tissues(SALT)
mucosa-associated lymphoid tissues(MALT)
tonsils
breasts of pregnant and lactating women
gut-associated lymphoid tissue(GALT)
171
tonsils
active source of lymphocytesin in the pharynx
172
pever's patches
compact aggregations of lymphocytes in the ileum of the small intestine
173
cytokines
hundreds of small active molecules secreted to regulate, stimulate, suppress and otherwise control many aspects of cell development, inflammation, and immunity
produced by monocytes, macrophages, lymphocytes, fibroblasts, mast cells, platelets, and endothelial cells
174
reticulum
support network of collective tissue fivers that permeate the tissues of the body
interconnects nearby cells and meshes with the massive connective tissue that surrounds every o
175
where is the mononuclear phagocyte system found
thymus
lymph nodes
tonsils
spleen
lymphoid tissue of the mucosa of the gut and respiratory tract
176
first line of defense
physical and chemical barriers that impede the entry of microbes and foreign agents, whether living, or
177
stratum corneum
tough outer layer of skin that is impervious and waterproof
178
build-in defenses of mucous membranes
mucous coat impedes entry and attachment of bacteria
blinking and tear production flush the eye's surface
constant flow of saliva carries microbes to the harsh conditions of the stomach
vomiting and defecation evacuate noxious substances of substances or microorganisms of body
179
genitourinary tract
protection through continous trickle of urine through ureters
periodic bladder emptying flushes urethra
vaginal secretions provide cleansing of lower reproductive tract in females
180
nonspecific chemical defenses
sebaceous secretions exert an antimicrobial effect
specialized glands of eyelids lubricate the conjunctiva with an antimicrobial secretion
181
lysozyme
enzyme found in tears and saliva that hydrolyzes the peptidoglycan in the cell wall of bacteria
182
what is the effect of barrier loss
loss of immunity or absence of normal immunity demonstrates the vital need for barriers of all types
patients with severe burns are very susceptible to all kinds of infections
183
what do phagocytes do
survey the tissue compartments and discover microbes, particulate matter, and injured or dead cells
184
what are the types of phagocytes
neutrophils
monocytes(macrophages, dendritic cells)
185
neutrophils
react early in the inflammatory response to bacteria and other foreign materials and to damaged tissues
186
what do monocytes turn into
macrophages after they migrate out of the bloodstream and into tissues
187
histocytes
live in a certain tissue and remain there during their life span
alveolar(lung) macrophages
knupffer cells in liver
dendritic cells in skin
macrophages in spleen
188
histiocyte cells
differentiated macrophage cells that take up residence in organs or tissues
189
phagocytosis
physical process of engulfment
attack and dismantling of foreign cells
can be an isolated event or as part of the orchestrated events of inflammation
190
events of phagocytosis
1. chemotaxis
2. adhesion
3. ingestion(engulfment)
4. phagolysosome formation
5. phagolysosome formation and killing
6. destruction
7. excretion
191
pathogen-associated molecular patterns
signal molecules found on microbial surfaces recognized by phagocytes and other defensive cells
molecules shared by many organisms, but not present in mammals
serve as "red flags" for phagocytes and other cells of innate immunity
192
what are the bacterial PAMPS
peptidoglycan and lipopolysaccharide
193
pattern recognition receptors
found on phagocytes, dendritic cells, and lymphocytes
recognize and bind PAMPS
cells possess PRRs whether they have encountered PAMPS before or not
194
inflammasomes
PRRS found within the cytoplasm of phagocytic cells of the innate immune system
195
rubor
redness caused by increased circulation and vasodilation in the injured tissue
196
calor
warmth caused by heat given off by increased flow of blood
197
tumor
swelling caused by fluid escaping into the tissues
198
dolor
pain caused by the simulation of nerve endings
199
inflammatory response
can be local or systemic
200
factors that elicit inflammation
trauma from infection
tissue injury or necrosis due to physical or chemical agents
specific immune reactions
201
chief functions of inflammation
to mobile and attract immune components to the site of injury
to set in motion mechanisms to repair tissue damage and localize and clear away harmful substances
destroy microbes and block their further invasion
202
chemotaxis
migration of cells in response to a specific chemical stimulus
cells swarm from many compartments to the site of infection and remain there to perform general and specific immune functions
203
cytokines
released by phagocytic cells to other lymphocytes
small soluble proteins have specific roles in host defense
204
chemokines
cytokines that attract more phagocytes to infection site
205
mast cells
do not circulate in blood, found in connective tissue and mucosa
role in inflammation, wound healing, allergic responses
206
degranulation
release contents of granules(contain histamine) into extracellular environment causing vasodilation
influence tone and diameter of blood vessels
207
pus
accumulation of dead phagocytes
injured or damaged cells
remains of ingested organisms
208
benefits of edema
influx of fluid dilutes toxic substances
fibrinclot can trap microbes to prevent further spread
209
pyogenic
bacteria such as streptococci, staphylococci, gonococci, and meningococci that stimulate the formation of pus
210
fever
abnormally elevated body temperature
nearly universal symptom of infection
211
fever of unknown origin
don't know why they have fever
212
low-grade fever
37.7-38.3 celsius; 100 to 101 fahrenheit
213
high-grade fever
40.0 to 41.4 celsius; 104 to 106 fahrenheit
214
pyrogens
substances that reset the hypothalmic thermostat to a higher setting
215
exogenous pyrogens
products of infectious agents such as viruses, bacteria, protozoans, fungi, endotoxin, blood, blood products, vaccines, or injectable solutions coming from outside the body
216
endogenous pyrogens
liberated by monocytes, neutrophils, and macrophages during phagocytosis such as interleukin-1 and tumor necrosis factor
217
benefits of fever
inhibits multiplication of temperature-sensitive microorganisms such as the poliovirus, cold viruses, herpes zoster virus, and systemic and subcutaneous fungal pathogens
impedes nutrition of bacteria by reducing the availability of iron
increases metabolism and stimulates immune reactions and naturally protective physiological processes
218
interferons alpha and beta
produced by lyphocytes, fibroblasts, and macrophages
219
interferons gamma
produced by T cells
220
characteristics of interferon
binding of viruses and other microbes to receptors on a host cell, signals the cell to produce interferon
interferon molecules are rapidly secreted into the extracellular space binding to other host cells
221
alternate complement pathway
does not require antibody to get started
initiated by the presence of foreign cell antigen
quicker response than the classical pathway
222
four steps in the alternative complement pathway
1. initiation
2. activation and cascade
3. polymerization
4. membrane attack
223
what is different about the third line of defense?
it is acquired only after an immunizing event such as infection
224
immunocompetence
the ability of the body to react to countless foreign substances
225
antigens
molecules that can be seen and identified by the immune system
226
immunogens
antigens that provoke a response
227
epitope
the precise molecular group of an antigen that defines its specificity and triggers the immune response
228
specificity
antibodies produced against chickenpox virus will not function against the measles virus
229
memory
lymphocytes have been programmed to recall their first engagement with the invader and rush to attack once again
230
major histocompatibility complex
one set of genes that codes for human cell markers or receptors
231
class I genes
code for markers that appear on all nucleated cells, display unique characteristics of self, allow for recognition of self molecules and regulation of immune reactions
232
class II genes
also code for immune regulatory markers found on macrophages, dendritic cells, and B cells, and are involved in presentation of antigens to T cells
233
class III genes
encode proteins involved with the complement system, among others
234
cluster of differentiation
cell surface glycoproteins that identify and differentiate white blood cells
235
lymphocyte receptors
major role is to accept or grasp antigens in some form
236
B cell lymphocyte receptors have
receptors that bind antigens
237
T cell lymphocyte receptors have
receptors that bind antigens that have been processed and complexed with MHC molecules on the presenting cell surface
238
helper t cells(Th)
activate macrophages, assist B-cell processes, and help activate cytotoxic T cells
239
regulatory T cells(Treg)
control the T-cell response by secreting anti-inflammatory cytokines or preventing proliferation
240
cytotoxic t cells(Tc)
lead to the destruction of infected host cells and other foreign cells
