Chapter 15 - We Are Not Alone Flashcards
1
Q
The human body exists in a state of _______ ___________ with microorganisms
A
Dynamic equilibrium
2
Q
Many interactions between human body and microorganisms involve the development of ________
A
Biofilms
3
Q
____________ of the body involves a constant “give and take”
A
Colonization
4
Q
Microbes that engage in mutual or commensal associations
A
Normal (residential) flora, indigenous flora, microbiota
5
Q
Causes infection
A
Pathogen
6
Q
Its in tissues and organs and causes disease
A
Infectious disease
7
Q
Most areas of the body in contact with the _______ ___________ harbor resident microboes
A
Outside environment
8
Q
What are microbe-free?
A
Internal organs, tissues, and fluids
9
Q
Microbes that occupy the body for only short periods
A
Transients (we pick these up)
10
Q
Microbes that become established
A
Residents (normal flora)
11
Q
What are the sites that harbor a normal flora?
A
- Skin and its contiguous mucous membranes
- Upper respiratory tract
- Gastrointestinal tract (various parts)
- Outer opening of urethta
- External genitalia
- Vagina
- External ear and canal
- External eye (lids, lash, follicles)
12
Q
What are all the internal tissues and organs that are sterile (microbe-free)
A
- Heart and circulatory system
- Liver
- Kidneys and bladder
- Lungs
- Brain and spinal cord
- Muscles
- Bones
- Ovaries/testes
- Glands (pancreas, salivary, thyroid)
- Sinuses
- Middle and inner ear
- Internal eye
13
Q
What are the fluids within an organ or tissue that are sterile (microbe-free)
A
- Blood
- Urine in kidneys, ureters, bladder
- Cerebrospinal fluid
- Saliva prior to entering the oral cavity
- Semen prior to entering the urethra
- Amniotic fluid surrounding the embryo and fetus
14
Q
Bacterial flora benefit host by preventing overgrowth of harmful microbes
A
RESIDENT FLORA
Microbial antagonism
Endogenous infections
15
Q
______ and contents are normally sterile and remain so until just before birth
A
Uterus
16
Q
Breaking of fetal membrane exposes the infant; all subsequent handling and feeding continue to introduce what will be ______ _____
A
Normal flora
17
Q
____ is the largest and most accessible organ
A
Skin
18
Q
What are two cutaneous populations?
A
- Transients
2. Residents
19
Q
The GI tract is a long hollow tube, bounded by what?
A
Mucous membranes
20
Q
Variations in flora distribution due to varying conditions like what?
A
pH, oxygen tension, and anatomy
21
Q
Oral cavity, large intestine, and rectum harbor which flora?
A
Substantial flora
22
Q
What has the most diverse and unique flora of the body?
A
Mouth
23
Q
The mouth has numerous adaptive ______
A
Niches
24
Q
What is the bacterial count of saliva?
A
5x10^(9 cells) per milliliter
25
Has complex and profound interactions with host
Flora of large intestine
26
10^8-10^11 microbes per gram of feces
Large intestine flora
27
Intestinal environment favors _________ bacteria
Anaerobic
28
Intestinal bacteria contribute to intestinal ____
Odor
29
Oral streptococci are the:
First organisms to colonize
30
Nasal entrance, nasal vestibule, anterior nasopharynx
S. aureus
31
Mucous membranes of nasopharynx
Neisseria
32
Tonsils and lower pharynx
Haemophilus
33
What ate the sites that harbor microflora?
Male and female genitourinary tract
34
Changes in physiology influence the composition of the ______ _____
Normal flora
| - Vagina (estrogen, glycogen, pH)
35
Normal flora is essential to the ______ of humans
Health
36
Flora create an environment that may prevent infections and can enhance host ________
Defenses
37
Antibiotics, dietary changes, and disease may:
Alter flora
38
Introducing known microbes back into the body
Probiotics
39
What are the major factors in the development of infection?
Portal of entry => Adhesion => Invasion => Multiplication => Infection of target => Disease => Portal of exit
40
Influenza virus, plague bacillus, malarial protozoan
True pathogens
41
Pseudomonas sp and Candida albicans
Opportunistic pathogens
42
Cause infection in perfectly healthy people
True pathogen
43
Only cause disease when host defenses are down
Opportunistic pathogen
44
More virulent, more pathogenic, refers to the degree of pathogenicity
Virulence
45
What are factors that weaken host defenses and increase susceptibility to infection?
- Old age and extreme youth (infancy, prematurity)
- Genetic defects in immunity and acquired defects in immunity (AIDS)
- Surgery and organ transplants
- Organic disease: cancer, liver malfunction, diabetes
- Chemotherapy/immunosupressive drugs
- Physical and mental stress
- Other infections
* These conditions compromise defense barriers or immune responses
46
What are the portals of entry?
- Skin
- Gastrointestinal tract
- Respiratory tract
- Urogenital tract
- Transplacental
47
Minimum number of microbes required for infection to proceed
Infectious Dose (ID)
48
Microbes with small IDs have greater _________
Virulence
49
Lack of ID will not result in _________
Infection
50
What are the ways of adhesion? (attaching to the host)
- Fimbrae
- Flagella
- Adhesive slimes or capsules
- Cilia
- Suckers
- Hooks
- Barbs
51
Initial response of host defenses comes from __________
Phagocytosis
52
Used to avoid phagocytosis
Antiphagocytic factors
53
Species of Staphylococcus and Streptococcus produce ___________, toxic to white blood cells
Leukocidins
54
Makes phagocytosis difficult
Slime layer or capsule
55
What are factors that cause disease?
- Virulence factors
- Exoenzymes
- Toxigenicity
- Antiphagocytic factors
56
What are the two types of toxigenicity?
- Endotoxin
| - Exotoxin
57
Produce inside cells
Endotoxin
58
Produce outside cells
Exotoxin
59
Possibly toxic, inside bacteria and secreted while still alive
Exotoxin
60
Inside bacteria until cells die
Endotoxin
61
Strong specificity for a target cell
- Hemolysis
- A-B toxins (A-active, B-binding)
Exotoxins
62
Lipopolysaccharide (LPS), part of the outer membrane of gram-negative cell walls
Endotoxins
| - often toxic
63
Very common products of gram-negative
| - Variety of systemic effects (common side effects)
Lipopolysaccharide (LPS)
64
What are four distinct stages of clinical infections?
- Incubation period
- Prodromal stage
- Period of invasion
- Convalescent period
65
Infection in a specific area
Localized infection
66
Infection that can effect the entire body
Systemic infection
67
Infection that starts local, but some microbes are able to move and cause an infection somewhere else too
Focal infection
68
Infection caused by a mixture of bacteria
Mixed infection
69
Infection that can lead to secondary infection
Primary infection
70
Infection from primary infection
Secondary infection
71
Infection that comes on rapidly and usually goes away quickly - doesn't last long
Acute infection
72
Infection that does not go away
Chronic infection
73
What are the earliest symptoms of disease as a result of the activation of the body defenses?
Fever, pain, soreness, swelling
74
What are the signs of inflammation?
- Edema
- Granulomas and abscesses
- Lymphadenitis
75
What are the signs of infection in the blood?
Changes in the number of circulating white blood cells
- Leukocytosis
- Leukopenia
- Septicemia
- Bacteremia
- Viremia
76
What does CBC stand for?
Complete blood count
77
Although infected, the host doesn't show any signs of disease
Asymptomatic (subclinical) infections
78
__________ _________, so person doesn't seek medical attention
Inapparent infection
79
Pathogens depart by specific avenue; greatly influences the dissemination of _________
Infection
80
What are the portals of exit?
- Respiratory-mucus, sputum, nasal drainage, saliva
- Skin scales
- Fecal exit
- Urogenital tract
- Removal of blood
81
Apparent recovery of host does not always mean the microbe has been _______
Removed
82
Damage that has been done to tissues or cells by an infectious agent
Sequelae
83
Primary habitat of pathogen in the natural world
Reservior
| - Human or animal carrier, soil, water, plants
84
Individual or object from which an infection is actually acquired
Source
85
An infection indigenous to animals but naturally transmissible to humans
Zoonosis
86
A live animal (other than human) that transmits an infectious agent from one host to another
Vector
87
The majority of vectors are __________
Arthropods
| - fleas, mosquitoes, flies, and ticks
88
Some larger animals can also spread _________
Infection
| - mammals, birds, lower vertebrates
89
Actively participate in a pathogen's life cycle
Biological vectors
90
Not necessary to the life cycle of an infectious agent and merely transports it without being infected
Mechanical vector
91
If a human has a zoonosis they ____ transmit it to others
Don't
92
At least ___ zoonoses exist worldwide; make up 70% of all new emerging diseases worldwide
150
93
With zoonoses it is impossible to eradicate the disease without eradicating the animal _________
Reservoir
94
What are nonliving reservoirs?
Soil, water, and air
95
A highly communicable disease is __________
Contagious
96
- Occurs primarily when a compromised person is invaded by his or her own normal microflora
- Contact with organism in natural, non-living reservior
Non-communicable infectious disease
97
What are the patterns of transmission?
- Direct contact
- Indirect contact
- Vehicle
- Airborne
98
Diseases that are acquired or developed during a hospital stay
- from surgical procedures, equipment, personnel, and exposure to drug-resistant microorganisms
- 2 to 4 million cases/year in the U.S. with approximately 90,000 death
Nosocomial infections
99
- Most commonly involve urinary tract, respiratory tract, and surgical incisions
- Most common organisms involved: gram-negative intestinal flora
- E. coli, Pseudomonas, Staphylococcus
Nosocomial infections
100
Stringent measures to prevent the spread of nosocomial infections from patient to patient, from patient to worker, and from worker to patient
Universal precautions
101
Universal precautions are based on the assumption that all patient specimens could harbor __________ ______, so they must be treated with the same degree of care
Infectious agents
102
The study of the frequency and distribution of disease and health-related factors in human populations
Epidemology
103
Collecting, analyzing, and reporting data on rates of occurrence, mortality, morbidity, and transmission of infections
- Reportable, notifiable diseases must be reported to authorities
Surveillance
104
Number of people killed
Mortality
105
Number of people infected
Morbidity
106
What does CDC stand for?
Centers for Disease Control and Prevention
107
Where is the CDC located?
Atlanta, GA
108
Principal government agency responsible for keeping track of infectious diseases nationwide
CDC
109
Spreads to large region
Epidemic
110
Spreads worldwide
Pandemic
