Brainscape's Knowledge GenomeTM

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


See full index

Biology > Diesease And Immunity UNIT 1 > Flashcards

Diesease And Immunity UNIT 1 Flashcards

0
Q

Examples of pathogenic microorganisms include

A

Some Bacteria
Some Fungi
All Virus

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

What is a pathogen

A

An organism that causes disease. Pathogens include microorganisms and some larger organisms like tapeworms

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

How do pathogens enter the body

A

They get in through an organisms (interphase) surface of contact with the environment eg nose, eyes, a cut.

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

3 main interfaces with environment

A

Gas exchange system
Skin
Digestive system

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

Info on gas exchange interphase

A

If you breathe in air that contains pathogens, most will be trapped in the mucus lining of the lung epithelium. These cells have cilia ( hair-like structures) that beat and moves the mucus up the trachea to the mouth where it is removed. However some pathogens are still able to reach the alveoli where they can invade cells and cause damage

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

Info on skin interphase

A

If you damage your skin, pathogens on the surface can enter your bloodstream. The blood clots at an area of damage to prevent pathogens from entering, but some may still get in before the clot forms.

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

Info on digestive system interphase

A

If you eat or drink food that contains pathogens, most of them will be killed by the acidic conditions of the stomach. However some may survive and pass into the intestines where they can invade cells of the gut wall and cause disease

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

What is a host cell

A

The cell the pathogen has invaded and is reproducing inside in

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

2 ways pathogens cause disease

A

Production of toxins

Cell damage

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

How does the production of toxins cause disease

A

Many bacteria release toxins into the body.
Eg the bacterium that causes tetanus produces a toxin that blocks the function of certain nerve cells, causing muscle spasms

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

How does cell damage cause disease

A

Pathogens can physically damage host cells by
Rupturing them to realise nutrients inside them
Breaking down nutrients inside the cell for their own use. This starves and eventually kills the cell
Replicating inside the cells and bursting them when they’re released

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

What is an antigen

A

They are molecules found on the surface of cells which cause an immune response and the production of antibodies

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

What are the 4 stages in the immune response

A

Phagocytes engulf pathogens
Phagocytes actives T-cells
T-cells active B-cells, which divide into plasma cells
Plasma cells make more antibodies to a specific antigen

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

What is a phagocyte

A

Is a type of white blood cell that carries out phagocytosis ( engulfment of pathogens)
They are found in the blood and in tissues and are the first cells to respond to a pathogen inside the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is an antibody

A

They are proteins that bind with antigens to form an antigen-antibody complex. The specificity of an antibody depends on its variable regions. Each antibody has a different shaped variable region that is complimentary to specific antigen.

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

How do phagocytes work

A

It recognises the antigens on the pathogen
The cytoplasm of the phagocyte moves around the pathogen, engulfing it
The pathogen is now contained in the phagocytic vacuole in the cytoplasm of the phagocyte
A lysosome fuses with the phagocytic vacuole and the lysosomal enzymes break down the pathogen
The phagocyte then presents the pathogens antigens, it sticks the antigens on it’s surface to activate other immune system cells

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

How do phagocytes activate T-cells

A

A T-cell is another type of white blood cell. It has proteins on its surface that bind to the antigens presented to it by phagocytes. This activate the T-cell.
Different types of T-cells respond in different ways….
Some release substances to activate B-cells
Some attach to antigens on a pathogen and kill the cell

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

How do T-cells activate B-cells

A

B-cells are also a white blood cell. They are covered in antibodies Each B-cell has a differently shaped antibody on its membrane, so different ones bind to different antigens
When the antibody on the surface of a B-cell meets a complementary shaped antigen, it binds to it
This, together with substances released form T-cells activates the B-cell
This then divides into plasma cells

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

How do plasma cells make more antibodies

A

Plasma cells are identical to the B-cell. They secrete loads of the antibody specific to the antigen. Antibody functions include…
Coating the pathogen to make it easier for the phagocyte to engulf it
Costing the pathogen to prevent it from entering host cells
Binding to and neutralising toxins produced by the pathogen

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

What is the lung epithelium

A

The outer layer of cells in the passages to the lungs

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

What are cilia

A

Hair like structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a toxin

A

It’s a harmful molecule in the body

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

What can affect the risk of developing some diseases

A

Your lifestyle

23
Q

What is CHD

A

Coronary heart disease, disease of the heart

24
Q

Name 5 lifestyle factors that increase your risk of developing CHD

A 
Poor diet-rich in saturated fats and salts
Lack of exercise
Smoking
Excessive Alcohol intake 
High blood pressure

These factors damage the heart and block the vessels which increases your risk of developing CHD

25
Q

Factors that increase the risk of developing cancer

A

Smoking (lung, throat,mouth cancer)
Excessive alcohol intake (liver cancer)
Sunlight (skin cancer)

26
Q

Foreign antigens trigger what?

A

An immune response

27
Q

Antigens are molecules which are usually…..

A

Proteins or polysaccharides

28
Q

What is phagocytosis

A

The engulfment of pathogens

29
Q

The immune response is often split into….

A

two

The cellular and humoral response

30
Q

2 parts to immune response

A

Cellular and humoral response

31
Q

What is cellular response

A

The T cells and other immune system cells that they interact with, eg phagocytes

32
Q

What is humoral response

A

B-cells and the production of antibodies

33
Q

Do the cellular and humoral responses work together

A

Yes, both are needed to remove a pathogen from the body and the responses interact with each other, T-cells activate B-cells and antibodies coat pathogens making it easier for the phagocytes to engulf them

34
Q

What is the primary response in the immune response

A

This is when an antigen enters the body for the first time and it activates the immune system. The primary response is slow as there aren’t many B-cells that can make the antibody needed to bind to it. Eventually the body produces enough of the right antibody to overcome the infection. Meanwhile the infected person will show symptoms of the disease. After being exposed to the antigen, both T- and B-cells produce memory cells, which remain in the body for a long time. Memory T-cells remember the specific antigen and will recognise it a second time round. Memory B-cells record the specific antibodies needed to bind the antigen. The person is now immune- their immune system has the ability to respond quickly to a 2nd infection.

35
Q

Where are B-cells formed in the body

A

Bone marrow

36
Q

Where are T-cells formed in body

A

Formed in bone marrow, mature in thymus

37
Q

What is the secondary response of the immune response

A

If the same pathogen enters the body again, the immune system will produce a quicker, stronger immune response.
Memory B-cells divide into plasma cells that produce the right antibody to the antigen. Memory T-cells divide into the correct type of T-cells to kill the cell carrying the antigen. The secondary response often gets rid of the pathogen before you begin to show any symptoms.

38
Q

What does a vaccine contain

A

Antigens that cause your body to produce memory cells against a particular pathogen, without the pathogen causing disease. This means you become immune without getting any symptoms

39
Q

What is herd immunity

A

when the vaccination of a significant portion of a population (or herd) provides a measure of protection for individuals who have not developed immunity,as it makes it difficult for the disease to spread because there are so few susceptible people left to infect

40
Q

The antigens in the vaccine may be…..

A

Free or attached to a attenuated (weakened) pathogen

41
Q

Vaccines may be injected or…

A

Taken orally. Disadvantages of grid are that it could be broken down by enzymes in the gut or the molecules of the vaccine may be too large to be absorbed into the blood

42
Q

Why are booster vaccines given

A

To make sure that memory cells are produced

43
Q

What is antigenic variation

A

Antigens on the surface of pathogens activate the primary response. When the body is infected a second time with same pathogen, they activate the secondary response so you don’t get ill. However some pathogens can change their surface antigens (formed due to changes in the genes of a pathogen)

44
Q

What happens due to antigenic variation

A

Means that when you are infected for a second time, the memory cells produced from the first infection will not recognise the different antigens. So the immune system has to start again and carry out the primary response against the new antigens. This primary response takes time to get of the infection, which is why you get ill again. This makes it difficult to develop vaccines against some pathogens for the same reason.

45
Q

Examples of pathogens with antigenic variation

A

HIV, influenza virus

46
Q

Explain antigenic variation in the influenza virus

A

The influenza virus causes influenza. Proteins (neuraminidase and haemagglutinin) on the surface of the influenza virus act as antigens, triggering the immune system. These antigens can change regularly, forming new strains of virus. Memory cells produced from infection with one strain of flu will not recognise other strains with different antigens. This means your immune system produces a primary response every time your infected with a new strain, this means you can suffer from flu more than once

47
Q

What are monoclonal antibodies

A

Antibodies produced from a single group of genetically identical
B-cells, making them identical in structure

48
Q

What are monoclonal antibodies used for

A

To target specific substances or cells

49
Q

Example of using monoclonal antibodies to target cells

A

Cancer

50
Q

Example of using monoclonal antibodies to target substances

A

Pregnancy tests

51
Q

Explain monoclonal antibodies in the use of treating cancer

A

Cancer cells have antigens called tumour markers that aren’t found on normal body cells. The monoclonal antibodies can be made to bind to the tumour markers. You can also attach anti-cancer drugs to the antibodies. When the antibodies come into contact with the cancer cells they bond to the tumour markers, means the drug will only accumulate in the body where there are cancer cells. Means side effects of the antibody-based drug is lower than other drugs because they accumulate near specific cells.

52
Q

Explain monoclonal antibodies in testing for pregnancy

A

Pregnancy tests detect the hormone human chorionic gonadotropin (hcg) that’s found in urine. The application area contains antibodies for hcg bound to a coloured bead ( blue). When urine is applied to the application area any hcg will bind to the antibody on the beads, forming an antigen-antibody complex.. The urine moves up the stick to the test strip, carrying any beads with it. The test strip contains antibodies to hcg that are stuck in place. If there is hcg present the test strip turns blue because the immobilised antibody binds to any hcg- concentrating the hcg antibody complex with the blue beads attached. If no hcg present the beads will pass through the test area without bonding to anything so it don’t go blue.

53
Q

What do scientists do to validate a theory

A

They may repeat or try to reproduce the results

Or conduct other studies to try to prove the same theory

54
Q

Ethical issues surrounding vaccines

A

All vaccines tested on animals before being tested on humans. Some disagree with animal testing. Also animal based substances may be used to produce a vaccine, which some disagree with.
Testing vaccines on humans is tricky, eg volunteers may put themselves at unnecessary risk of contracting the disease because they think they’re fully protected.
Some don’t want to take the vaccine due to risk of side effects, but they are still protected due to herd immunity- some think this is unfair.
If there is an epidemic of a new disease there would be a rush to receive a vaccine and difficult decisions would have to be made about who would be the first to receive it

55
Q

Ethical issues surrounding monoclonal antibody therapy

A

Often involve animal rights issues. Animals used to produce the cells from which monoclonal antibodies are produced. Some people disagree with the use of animals in this way

Biology (13 decks)

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