Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO 140 - Microbiology > LO 2 > Flashcards

LO 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

_______ is an intimate relationship between two dissimilar organisms. The larger organism is referred to as a ______ and the small as a _____

A
  1. Symbiosis
  2. Host
  3. Symbiont
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the three types of symbiosis?

A
  1. Mutualism
  2. Commensalism
  3. Parasitism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe mutualism with an example

A
  1. Both the symbiont and the host benefit
  2. E.g. e coli in the intestines - benefit to the bacteria is that they have a place to survive and multiply, benefit to the human is that bacteria May produce vitamins such as B&K and break down food that the host can’t normally digest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe commensalism with an example

A
  1. One of the participants, typically the symbiot, benefits and the other one is unaffected - neither benefits or is harmed
  2. E.g. corynebacteria that inhabit the surface of the eye (live on secretions)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is microbial antagonism?

A
  1. A special type of commensalism that is microbial competition
  2. A microbe doesn’t hurt under ordinary circumstances and also doesn’t overtly help its host but may still provide a helpful service
  3. Normal flora protect the host against infection by pathogenic organisms by - taking up space so pathogens have nowhere to set up shop, may out-compete the invader for available nutrients, May produce antibacterial chemicals (bacteriocins), this prevention of harmful bacterial growth by a non harmful bacterium is called microbial competition or microbial antagonism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe parasitism with an example

A
  1. The host is harmed while the symbiont (called a parasite) gains - the latter, for example by having a place to live and something to eat
  2. E.g.viral infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the conditions that could cause one type of symbiotic relationship to shift to another type

A
  1. Hosts conditions change (burns, lacerations, surgeries, etc)
  2. E.g. mutualistic relationships between humans and their indigenous Flora can shift to a parasitic disease causing relationship
  3. Normally harmless microfluora can become pathogenic if it enters a wound (oral streptococci is harmless in the mouth but can cause infective endocarditis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe synergism

A
  1. Two or more microorganisms team up to produce a disease that neither of them could cause by itself
  2. Oral bacteria like fusobacterium, actinomyces, prevotella spp, and spyrochetes can work together to cause NUG (necrotizing ulcerative gingivitis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Normal microbiota in hosts is also called ________

A
  1. Normal flora and indigenous microbiota
  2. These are organisms that colonize the body surfaces without normally causing disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two types of normal microbiota?

A
  1. Resident microbiota
  2. Transient microbiota
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe resident microbiota

A
  1. They are a part of the normal microbiota throughout life and are mostly commensal
  2. Contained on the skin and in the GI tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe transient microbiota

A
  1. Remain on the body for short periods
  2. Found in the same regions as resident microbiota
  3. Cannot persist in the body - competition from other microorganisms, elimination by the body’s defense cells, chemical or physical changes in the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe opportunistic pathogens

A
  1. Normal microbiota that cause disease under certain circumstances
  2. Conditions that provide opportunities for pathogens include - transfer of normal microbiota to other parts of the body, elimination of microbial antagonism, host immune suppression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are five major causes of disease in the body?

A
  1. Malfunctioning of an organ- hyperthyroidism or diabetes
  2. Nutritional deficiency - rickets and scurvy
  3. Allergic reaction - hay fever, asthma, poison ivy
  4. Abnormal growth of cells - Cancers and tumors
  5. Infectious disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe infectious disease

A
  1. Occurs when microorganisms in the body multiply and cause damage to the tissues
  2. The microorganisms that cause infectious disease are called pathogens
  3. The two types of infectious disease are endogenous and exogenous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The two types of infectious disease are ________ and _______

A
  1. Endogenous
  2. Exogenous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe endogenous disease

A
  1. Caused by microorganisms that are normally present on or in the body without causing harm but something happens that allows them to express their disease producing potential
  2. Dental caries, pulpitis, periodontal disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe exogenous disease

A
  1. Caused by microorganisms that are not normally present on or in the body but contaminate the body from the outside, most infectious disease fits in this category
  2. Hepatitis b, strep throat, aids, measles
  3. If it can cause disease without entering and multiplying in the body it is a toxogenic disease, may occur after eating food in which microorganisms have multiplied and produced toxins or poisons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What three facts are key to remember in the transmission of infectious disease?

A
  1. A specific chain of events must occur before a person can become infected with a disease
  2. If any Link in that chain of events is broken, the infection will not occur
  3. If a pattern of precautions is undertaken at every patient contact the spread of an infectious disease is minimized
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the six steps of exogenous infectious disease development?

A
  1. The Source or reservoir of microorganism
  2. Escape of microorganism from the source (portal of exit)
  3. Spread of microorganism to a new person (mode of transmission)
  4. Entry of microorganism into the person (portal of entry)
  5. Infection (survival and growth of microorganism)
  6. Damage to the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe source or reservoir

A
  1. Reservoirs of infection are sites where pathogens are maintained as a source of infection - most pathogens cannot survive for long outside of their host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the three types of reservoirs

A
  1. Animal reservoirs
  2. Human carriers
  3. Nonliving reservoirs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

_______ is an infectious disease that is transmitted between species from animals to humans

A

Zoonosis (zoonoses plural)

Can be acquired through various routes - direct contact with animal or its waste, eating animals, blood sucking arthropods

Humans are usually a dead end host to zoonotic pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe human carriers

A
  1. Symptoms may occur at different stages during infectious disease
  2. Some individuals eventually develop illness while others never do - asymptomatic or healthy carriers are infected individuals who are asymptomatic but infective to others
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

______, _______, and ______ can be reservoirs of infection due to the presence of microorganisms often due to contamination by feces or urine

A

Soil, water, and food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe escape from the Source / portal of exit

A
  1. Pathogens leave the host through
    portals of exit
  2. Many portals affected are the same as portals of entry
  3. Pathogens often leave hosts in materials the body secretes or excretes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe spread/mode of transmission

A
  1. Transmission is from a reservoir, through portal of exit to another hosts portal of entry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the four modes of transmission?

A
  1. Direct contact
  2. Indirect contact
  3. Droplet infection
  4. Airborne infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe direct contact

A
  1. Touching
  2. Penetration through small breaks or cuts in the skin
  3. E.g. herpes infection spread
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe indirect contact

A
  1. Can result from injuries with contaminated sharps and contact with contaminated instruments, equipment, surfaces, and hands
  2. Can carry a variety of pathogens do to the presence of blood, saliva, or other secretions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe droplet infection

A
  1. Encompasses large particle droplets batter and transmitted by close contact
  2. May enter unprotected broken skin or mucous membranes of eyes, noses, mouths of members of dental team
  3. Big reason for PPE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe airborne infection

A
  1. Involves small particles
  2. Can remain airborne for hours and can be inhaled
  3. E.g. tuberculosis, chicken pox, measles

PPE***

33
Q

A ______ infection involves the spread of infection via insects

A

Vector-borne

34
Q

Describe entry into a new person / portal of entry

A
  1. Microorganisms that are spread to a new person frequently cause no damage unless they actually enter the body
  2. Four major routes - skin, mucous membranes, inhalation, ingestion
35
Q

Describe how pathogens enter the skin

A
  1. Microorganisms at the surface of the skin can enter through small cuts or abrasions that are often unnoticed
  2. Injuries with a contaminated sharp item cause direct penetration through the skin into the body
36
Q

Describe how pathogens enter mucous membranes

A
  1. Mucous membranes line body cavities that are open to the environment
  2. They provide a moist, warm environment hospitable to pathogens
  3. The respiratory tract is the most common site of entry - entry through the nose, mouth, or eyes
  4. Gastrointestinal tract maybe a route of entry - must survive the acidic pH of the stomach
37
Q

Define infection

A
  1. Infection is the multiplication and survival of microorganisms on or in our bodies
  2. Infection does not always mean disease, but disease seldom results without infection
38
Q

What are the four common stages of infectious diseases?

A
  1. Incubation stage - no signs or symptoms
  2. Prodromal stage -vague, general symptoms
  3. Acute stage - illness stage
  4. Convalescent stage - no signs or symptoms

*Pathogens may be spread to others during each of these stages

39
Q

Describe the incubation stage

A
  1. Period in which the initial entrance of infectious agent into the body to the time in the first symptoms appear
  2. Disease agent is multiplying and may or may not be producing harmful effects
  3. Ranges from a few hours to years - e.g. influenza (2-3 days), HepB (several weeks), HIV-1 (10+ years)
40
Q

Describe the prodromal stage

A
  1. Stage of disease involving the appearance of early symptoms
  2. Microorganisms multiply to large enough numbers to cause the first symptoms (malaise)
  3. You are vaguely aware that you’re sick - may include fever, headache, or upset stomach
41
Q

Describe the acute stage

A
  1. The stage when symptoms of the disease are maximal in the person is obviously ill - also called the period of illness
  2. Communicable diseases are most easily transmitted during this period
  3. People in this phase are unlikely to come to the dental office
42
Q

Describe the convalescent stage

A
  1. Also called The recovery phase
  2. Microorganisms are decreasing in number
  3. Infectious agents are still present and may still spread during the stage
  4. Chronic stages may occur in diseases such as hepatitis B and tuberculosis
43
Q

Describe infectious disease in contrast to non-infectious disease

A
  1. An infectious disease, as opposed to a non infectious disease, is a disease that involves a pathogen infection
  2. Any disease caused by a pathogen is an infectious disease. Any disease not caused by a pathogen is a non infectious disease
44
Q

What are the five types of infections?

A
  1. Acute infection - an acute infection develops rapidly but is soon over, for example food poisoning
  2. Chronic infection - a chronic infection develops slowly and is not soon over, for example tuberculosis
  3. Latent infection - a latent infection is signless or symptomless for a long while before signs and symptoms appear, for example AIDS
  4. Local infection - a local infection is confined to a certain area, for example a pimple
  5. Systemic infection - A systemic infection spreads throughout the body in the blood or lymph
45
Q

Describe communicable diseases

A
  1. A communicable disease is an infectious disease that may be passed from individual to individual (particularly when all individuals involved are of the same species)

Not all infectious diseases are considered communicable

46
Q

Describe non-communicable diseases

A
  1. An infectious disease that is not spread from individual to individual, but instead is acquired from an inanimate object or other species
47
Q

What are the three categories of non-communicable diseases?

A
  1. Infections caused by opportunists - arising from an individual’s own microflora
  2. Poisonings following ingestion of secreted exotoxins - A soluble toxin secreted by microorganisms into their surroundings including host tissues
  3. Infections acquired from organisms found in the environment - other than from individuals of one’s own species
48
Q

What is a contagious disease?

A
  1. A communicable disease that is easily passed from individual to individual
  2. Not all communicable diseases are considered contagious - though certainly all contagious diseases are considered communicable
49
Q

What are the factors that influence the development of infection/disease?

A
  1. The number of organisms and the duration of exposure
  2. Virulence of the organisms - ability to cause damage to a host
  3. Immune status of the host
  4. General physical health and nutritional status of the host
50
Q

What are pathogenic properties of microorganisms?

A
  1. Enhancement of infection
  2. Interference with host defenses
  3. Direct damage to the body
51
Q

_____ is the process by which microorganisms attach themselves to cells, which is required to successfully establish colonies within the host

A

Adhesion (enhancement of infection)

52
Q

What are adhesion factors?

A
  1. Specialized structures such as surface fimbriae
  2. Attachment proteins - on bacteria and viruses, for example S. mutans attachment to AP proteins through its own surface proteins
  3. Some bacterial pathogens attached to each other to form a biofilm
53
Q

Describe how pathogens interfere with host defenses

A
  1. Bacteria with capsules
  2. Resistance to phagocytic engulfment - production of toxins that kill white blood cells, production of protease enzymes that destroy antibody molecules
54
Q

Describe how pathogens cause direct damage to the body

A
  1. Production of extracellular enzymes that can degrade macromolecules - kill cells or damages tissues if these macromolecules are part of the host cell surface or tissue components, viruses can damage by killing or interfering with normal cell function
  2. Production of waste products that are cytotoxic - lactic acid production (enamel demineralization)
55
Q

_____ is the ability of a microorganism to cause disease

A

Pathogenicity

56
Q

_____ is the degree of pathogenicity

A

Virulence

57
Q

What are the five virulence factors?

A
  1. Adhesion
  2. Biofilms
  3. Extracellular enzymes
  4. Toxins
  5. Antiphagocytic factors
58
Q

Describe extracellular enzymes of infectious agents

A
  1. Secreted by pathogens
  2. Dissolve structural chemicals in the body
  3. Help pathogen maintain infection, invade, and avoid body defenses
59
Q

Describe toxins of infectious agents

A
  1. Chemicals that harm tissues or trigger host immune responses that cause damage
  2. Toxemia refers to toxins in the bloodstream that are carried beyond the site of infection
  3. There are two types exotoxins and endotoxins
60
Q

Describe antiphagocytic factors of infectious agents

A
  1. Factors that prevent phagocytosis by the host’s phagocytic cells
  2. Bacterial capsule-composed of chemicals not recognized as foreign, slippery
  3. Antiphagocytic chemicals - prevent fusion of lysosome and phagocytic vesicles, leukocidins directly destroy phagocytic white blood cells
61
Q

What are the two categories of host defense mechanisms against harmful infections?

A
  1. Innate defenses- always active
  2. Acquired defenses- must always be stimulated to become active
62
Q

What are the four innate host defenses the body has to guard against infection by contaminating microorganisms?

A
  1. Physical barriers
  2. Mechanical barriers
  3. Antimicrobial chemicals
  4. Cellular barriers
63
Q

Describe physical barriers to infectious disease

A
  1. Intact, unbroken skin - structure and composition (waterproof keratin) provide resistance to infection
  2. Skin is not a great place for bacteria to live if it - dries, sheds, secretes
  3. Mucus membranes of the eyes, nose, mouth, respiratory tree, vagina, and intestinal tract
64
Q

What are mechanical barriers to infection?

A
  1. Include cleansing action of secretions (saliva, tears, excretion of urine) - mucus traps many microorganisms that enter the respiratory and gastrointestinal tracts
  2. Coughing and sneezing
  3. Desquamation of skin cells - shedding
65
Q

Describe antimicrobial chemicals in the body

A
  1. Hydrochloric acid - in stomach and organic acids on skin / vagina can prevent multiplication of microorganisms
  2. Lysosome - kills and lyses bacteria in saliva, tears, nasal secretions, intestinal secretions, colostrum and inside phagocytes
  3. Interferon-released from infected cells to make nearby cells resistant to viral replication
  4. Compliment system - group of proteins present in blood and tissues fluids that work with immune response to attract phagocytes to sites of infection
66
Q

Which white blood cells destroy microorganisms by phagocytosis?

A
  1. Neutrophils
  2. Macrophages
67
Q

Describe the steps of phagocytosis

A
  1. Chemotaxis - phagocytes are attracted to the site where they are needed
  2. Attachment - a phagocyte attaches to an object
  3. Ingestion - pseudopodia surround the object, and it is taken into the cell
  4. Digestion - the object is broken down and dissolved by digestive enzymes and other mechanisms
68
Q

Describe acquired immunity

A
  1. The state of being resistant to harmful effects of a specific microorganism
  2. Innate host defenses are always active. Acquired immunity defenses are only activated after an infection has occurred
  3. In most cases, as each new microbial invader is encountered, our adaptive immune response initiates a specific attack against the invader. Generally The invader is remembered and that “memory” is readily available in case of a second attack
69
Q

What are other terms for acquired immune response?

A

Adaptive immunity or specific immunity

70
Q

Immune responses are activated by ______

A

Antigens (antigens can be found on bacteria, fungi, viruses, protozoa etc)

71
Q

Antigens are recognized as ______ by special macrophages that process antigens through ____ and interact with the cells of the immune system (B and T lymphocytes)

A
  1. Foreign “stuff”
  2. Phagocytosis
72
Q

Describe antigens

A
  1. The term antigen derrives from the two words antibody generator
  2. Particular chemical that will activate the adaptive immune response
  3. Most antigens are proteins or large polysaccharides
  4. Often a component of invading microbes, such as the capsule, cell wall, flagella, toxin
73
Q

What are the two methods of microorganism destruction response by the body?

A
  1. Cell mediated response
  2. Antibody mediated response (humoral response)
74
Q

Describe the cell mediated response

A

Activated T lymphocytes develop into specialized T lymphocytes that:
1. Regulate the antibody mediated response
2. Destroy virus infected host cells to stop multiplication of the virus
3. Produce chemicals called lymphokines that activate other phagocytes to kill invading microorganisms
4. Destroy non-microbial cells in the body that have changed and become recognized to the body as foreign (e.g. a cancer cells)

75
Q

Describe the antibody-mediated response

A
  1. Activated B lymphocytes develop into specialized B lymphocytes that produce lymphokines or into plasma cells that produce antibodies
  2. Antibodies - protein molecules that bind to the specific antigen that originally stimulated their formation
  3. Antibody binds to antigen and they are destroyed, inactivated, or easily removed from the body
  4. Protection gained from the formation of antigen-antibody complexes basically comes down to the tagging of foreign cells and molecules for destruction by phagocytes and complement
76
Q

Describe long term immunity

A
  1. Initially, there is an increased number of lymphocytes activated that can respond to an invading microorganism
  2. During subsequent invasions, the body remembers the microorganism and lymphocytes can destroy it before it damages the body
77
Q

Describe artificial immunity

A
  1. Involves immunizations or vaccines
  2. Inoculations occur with an antigen (dead or weakened microorganism) which stimulates the immune system
78
Q

How do to vaccines work?

A
  1. Vaccines stimulate the body to produce protective antibodies that are directed against surface antigens
  2. When pathogens enter the body, antibodies attached to the surface antigens, this prevents pathogens from adhering to host cells
  3. In cases of viruses that can’t attach, can’t enter the cell, thus unable to multiply and cause cell destruction
79
Q

Describe body damage by the immune system

A
  1. 10% of the population is allergic to substances that can either serve directly as an antigen or are changed into antigens after they enter the body
  2. The immune response to this antigen results and damage to the body
  3. Can include pollens (hay fever or asthma), foods (expressed his hives), penicillin inoculation (anaphylactic shock)

BIO 140 - Microbiology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions