Brainscape's Knowledge GenomeTM

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


See full index

Principles of dizzees > Pathogens and the host > Flashcards

Pathogens and the host Flashcards

1
Q

What is the difference between a pathogen and a commensal?

A

Pathogens will cause disease whereas commensals are organisms that exist as part of the normal flora and do not cause harm

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

Define pathogenicity.

A

The capacity of a micro-organism to cause an infection

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

What 2 factors are essential in determining a virus’s pathogenicity?

A

Virulence

Infectivity

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

What does infectivity mean?

A

The ability of a pathogen to become established on or within a host

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

What structural feature of a bacterium increases it’s infectivity, and why?

A

Fimbriae

Allows attachment to cell

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

Helicobacter pylori infects in the stomach. What feature of it increases it’s infectivity?

A

It has acid resistance

Allows it to survive

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

What is virulence?

A

The capacity of a pathogen to cause harmful effects once established on or within a cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Virulence factors determine how harmful a pathogen is.

List the virulence factors.

A

Invasiveness
Toxin production
Evasion of immune system

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

Virulence factors are specific to strains, not species.

Give an example of a type of bacteria, who’s strains vary greatly in their virulence.

A

E. Coli

Some strains are completely harmless and live in gut normally

Some are not so good

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

What is the difference between infection and colonisation?

A

Infection will cause symptoms to show

Colonisation will not cause symptoms to show

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define colonisation.

A

When a pathogen grows at a site of infection, without causing symptoms to show

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

Using fancy words, a patient who’s body was the host to colonisation of bacteria would be what?

A

Asymptomatic

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

What is the difference between an acute infection, and a chronic infection?

A 
Acute = short term
Chronic = long term
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a sub-clinical infection?

A

Asymptomatic
Occult

No apparent symptoms

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

In general, what are the differences between the symptoms of a viral infection, and those of a bacterial infection?

A

Viral infections are systemic, and often affect more than one system at once. Affected systems/areas tend to be itchy and/or burning, and few are painful.

Bacterial infections often involve localised pain, swelling, redness and burning in a specific area, not a system.

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

Describe the 3 types of toxins.

A

Exotoxins - released by the pathogen

Enterotoxins - type of exotoxin - act in GI tract

Endotoxins - structurally part of gram negative cell wall

17
Q

Describe the structure of an endotoxin.

A

Lipopolysaccharide

Composed of lipid A, an oligosaccharide core and a specific polysaccharide chain

18
Q

Although bacterium can cause harmful effects using toxins, how else can infection of bacteria cause harm?

A

The host’s response

hypersensitivity and all that stuff

19
Q

What is the difference between a primary and a secondary infection?

A

Primary - Root cause of infection

Secondary - caused/allowed due to another infection

20
Q

When a latent virus goes into dormancy, how does it exist?

A

The virus is latent in the nucleus

21
Q

What is opsonisation?

A

Covering of pathogen in antibodies or compliment proteins

Phagocytic cells have receptors for both

Efficiency for phagocytosis is greatly improved

22
Q

What effect do compliment proteins have on the immune system?

A

Opsonise

Breakdown of Gram negative organisms

Compliment cascade signals polymorphs (neutrophils, eosinophils, basophils) to come to site of infection

23
Q

Humoral (extra-cellular) immunity MOSTLY deals with what type of infection; viral or bacterial? Acute or chronic?

A

Bacterial

Acute

24
Q

Cell mediated immunity MAINLY combats what type of infection?

A

Viral infection

some bacterial and some fungi

25
Q

What are the 3 types of vaccine?

A

Live attenuated

Killed (inactivated)

Toxoid

26
Q

What is a toxoid vaccine?

A

Toxin treated with formalin

Antigens remain but no toxic activity

27
Q

Bacterium X produces toxin Q

You are given a toxoid vaccination and all is good

You are exposed to bacterium X again. Describe what will happen.

A

Bacterium X is still able to colonise

However it can not infect you

Sub-clinical infection as no symptoms

Toxoid vaccinations are against the toxin, not the organism

28
Q

Why are live attenuated vaccinations difficult to administer in developing nations?

A

Must be refrigerated until they are given

29
Q

There is a risk with live-attenuating vaccinations that killed vaccinations do not have. What is this?

A

Risk of pathogen reverting back to ‘wild-type’

30
Q

What are the main sites of viral entry?

A 
Conjuctiva 
Respiratory tract 
Alimentary tract 
Urinogenital tract
Skin 
Capillaries (via a vector)

Principles of dizzees (28 decks)

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