Brainscape's Knowledge GenomeTM

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


See full index

MHD 1 > L10 Introduction to Medical Microbiology > Flashcards

L10 Introduction to Medical Microbiology Flashcards

1
Q

What are the 6 taxonomic categories of infectious agents?

A
  1. Prions
  2. Viruses
  3. Bacteria
  4. Fungi
  5. Protozoa
  6. Helminths
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two types of parasites?

A
  1. Protozoa

2. Helminths

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

___ consist of RNA or DNA contained in a protein shell; some are enveloped in a lipid membrane.

A

Viruses

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

Describe the spectrum of illnesses caused by viruses.

A
  1. Acute, transient illnesses (colds, gastroenteritis)
  2. Lifelong latency/long-term reactivation (herpes zoster)
  3. Chronic disease (Hepatitis B)
  4. Oncogenic (HPV, EBV)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Bacteria are ___ (unicellular or multicellular).

A

Unicellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are bacteria classified?

A
  1. Structural features of their envelope

2. Whether they are capsulated or unencapsulated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the spectrum of illnesses caused by bacteria.

A
  1. Low virulence
  2. Acute life threatening infections
  3. Chronic debilitating illness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Bacteria are capable of synthesizing their own DNA, RNA, and proteins; why do they need a host?

A

Favorable growth conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

___ are larger and more complex than bacteria. Growth patterns include budding yeast and slender tubes called ___.

A

Fungi; hyphae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the spectrum of illnesses caused by fungi.

A
  1. Infect superficial layers of skin
  2. Deep fungal infections can spread systematically
  3. Opportunistic fungi that normally colonize the body may cause disease in immunosuppressed patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the most complex microbes?

A

Parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

___ are parasitic, single-celled organisms with motility, pliable plasma membranes, and complex cytoplasmic organelles.

A

Protozoa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the spectrum of illnesses caused by protozoa.

A
  1. Invade and digest human tissues
  2. Replicate in and kill cells
  3. Damage tissue by inflammatory and immunologic responses
  4. Latent, can reactivate in immunocompromised host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

___ are parasitic worms; they are highly differentiated, multi-cellular organisms.

A

Helminths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or false - most helminths depend on an intermediary host or vector for asexual reproduction.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the three types of helminths?

A
  1. Roundworms (nematodes)
  2. Flatworms (trematodes)
  3. Tapeworms (cestodes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Helminths often cause disease by what mechanism?

A

Via host inflammatory responses to the helminths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are prions?

A

Misfolded protein aggregates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where do prions tend to aggregate?

A

CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the three major neurodegenerative diseases caused by prions?

A
  1. Kuru
  2. Bovine spongiform encephalopathy (mad cow disease)
  3. Creutzfeldt-Jakob disease (CJD)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How are prions transmitted?

A

Person to person, by surgery, organ transplantation, blood transfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the microbial population that colonizes the human body and where is it found?

A

Microbiome

Intestinal tract, skin, upper airway, vagina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the 4 major portals of entry of microbial infection?

A
  1. Skin
  2. GI tract
  3. Respiratory tract
  4. UG tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the two major defenses provided by the skin?

A
  1. Dense keratin layer

2. Low pH and fatty acids inhibit growth of microorganisms other than normal flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

True or false - some microorganisms can traverse unbroken skin.

A

True - schistosoma larvae penetrate skin by releasing enzymes that dissolve the ECM; certain fungi can infect intact stratum corneum, hair, and nails

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

What are the 6 major defenses provided by the GI tract?

A
  1. Acid secretions
  2. Layer of viscous mucous covering intestinal epithelium
  3. Lytic pancreatic enzymes and bile detergents
  4. Defensins (mucosal antimicrobial peptides)
  5. Normal flora
  6. sIgA made by plasma cells in MALT
27
Q

Infection via the GI tract occurs in what situations?

A
  1. Local defenses are weakened
  2. Organisms develop strategies to overcome defenses
  3. Pathogens transmitted by food/drink contaminated with fecal matter
28
Q

The distance inhaled viruses, bacteria, and fungi travel is ___ proportional to their size.

A

Inversely proportional

29
Q

What happens to large particles that enter the respiratory tract?

A

They are trapped in a mucociliary blanket (secreted by goblet cells) lining the nose and upper respiratory tract and transported by ciliary action to the back of the throat, where they are swallowed and cleared.

30
Q

What happens to particles smaller than 5 micron that get inhaled?

A

They travel directly to alveoli, where they are phagocytosed by alveolar macrophages or neutrophils recruited to the lungs by cytokines

31
Q

What are three major ways microorganisms that invade the normal healthy respiratory tract have developed to overcome mucociliary defenses/alveolar macrophages?

A
  1. Adherence (induces host cell to engulf virus, leading to viral entry and replication)
  2. Toxin release (can impair ciliary activity)
  3. Immune system evasion
32
Q

The UG tract is almost always invaded from the exterior by way of the ___.

A

Urethra

33
Q

___ of the urinary tract serves as defense against invading microorganisms.

A

Regular flushing w/urine

34
Q

Successful pathogens ___ to urinary epithelium.

A

Adhere

35
Q

Why do women have over 10x as many UTIs as men?

A

Distance between urinary bladder and skin is much shorter (5 cm in women, 20 cm in men)

36
Q

What are 4 ways microbes can spread within the host?

A
  1. Proliferate locally at the site of initial infection
  2. Lysis and direct invasion into the cell
  3. Spread through blood or lymphatics (either freely or within host cells)
  4. Cell to cell transmission
37
Q

All helminths are transported in the ___.

A

Plasma

38
Q

Most viruses spread locally cell to cell by what process?

A

Replication and release of infectious virions

39
Q

Some viruses propagate cell to cell causing ___ of cells; others transport within ___.

A

Fusion; nerves

40
Q

Transmission of microbes depends on the ___ of the microbe.

A

Hardiness

41
Q

What are 7 modalities of transmission of microbes?

A
  1. Contact (direct/indirect)
  2. Respiratory droplets
  3. Fecal-oral route
  4. Sexual transmission
  5. Urine
  6. Vertical transmission from mother to fetus/newborn
  7. Insect/arthropod vectors
42
Q

How do microbes cause disease?

A
  1. Enter host cells and directly cause death of cells
  2. Cause indirect damage via toxins, enzymes, or blood vessel damage
  3. Induce host immune responses
43
Q

After bypassing host tissue barriers, what else must infectious microorganisms do?

A

Evade host innate and adaptive immunity mechanisms to successfully proliferate and be transmitted to the next host

44
Q

What are 4 strategies of immune evasion by microorganisms?

A
  1. Antigenic variation
  2. Inactivating Ab or complement
  3. Resisting phagocytosis
  4. Suppressing the host adaptive immune response
45
Q

What are some mechanisms of antigenic variation?

A
  1. High mutation rate
  2. Genetic reassortment
  3. Genetic rearrangement
  4. Large diversity of serotypes
46
Q

What are the 5 major patterns of host responses to microorganisms?

A
  1. Neutrophil-rich acute suppurative inflammation
  2. Mononuclear inflammation
  3. Granulomatous inflammation
  4. Cytopathic-cytoproliferative reaction
  5. Chronic inflammation and scarring
47
Q

Suppurative/purulent inflammation is typical infections with many ___ and is characterized by ___.

A

Pyogenic; pus

48
Q

What is a localized collection of pus?

A

Abscess

49
Q

When is mononuclear inflammation typically seen?

A

All chronic inflammatory processes, some acute responses to viruses, intracellular bacteria, or intracellular parasites

50
Q

___ is a distinctive form of mononuclear inflammation.

A

Granulomatous inflammation

51
Q

When do granulomatous inflammations normally occur?

A

Evoked by infectious agents that resist eradication but nevertheless are capable of stimulating strong T cell-mediated immunity

52
Q

What happens in a cytopathic-cytoproliferative reaction?

A

Structural changes in host cells usually produced by viruses; lesions are characterized by cell necrosis or proliferation with sparse inflammatory cells; some viruses replicate within cells and make aggregates that are visible as inclusion bodies

53
Q

Many infections elicit chronic inflammation, which can either resolve with complete healing or lead to ___.

A

Extensive scarring

54
Q

What are two micro-organisms that elicit granulomatous responses?

A

TB, fungi

55
Q

What are 2 examples of microbes that demonstrate a high mutation rate?

A
  1. HIV

2. Influenza virus

56
Q

What are 2 examples of microbes that demonstrate genetic reassortment?

A
  1. Influenza virus

2. Rotavirus

57
Q

What are 4 examples of microbes that demonstrate genetic rearrangement?

A
  1. Borrelia burgdorferi
  2. N. gonorrhoeae
  3. Trypanosoma spp.
  4. Plasmodium spp.
58
Q

What are 2 examples of microbes that demonstrate a large diversity of serotypes?

A
  1. Rhinoviruses

2. S. pneumoniae

59
Q

The cause of amebic dysentery is a ___.

A

Parasite

60
Q

Give 2 examples of microbes that cause suppurative inflammation.

A

N. gonorrhoeae
S. pneumoniae
H. influenzae

61
Q

Give 2 examples of microbes that cause mononuclear inflammation.

A

Acute Hepatitis B

Syphilis

62
Q

Give 3 examples of microbes that cause granulomatous inflammation.

A

M. tuberculosis
Fungi
Schistosome eggs

63
Q

Give 1 example of a microbe that causes a cytopathic-cytoproliferative reaction.

A

Cytomegalovirus

64
Q

Give 1 example of a microbe that causes chronic inflammation and scarring.

A

Schistooma haematobium

MHD 1 (58 decks)

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