11. Immunity Flashcards

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

Name and describe 3 of the external defense system

A
  1. Epithelia that cover the airways are an effective barrier to the entry of pathogens
  2. Hydrochloric acid in the stomach kills many bacteria that we ingest with food and drink
  3. Blood clotting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two types of white blood cells?

A

Phagocytes and lymphocytes

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

What are antibodies?

A

Glycoprotein molecules that act against specific antigens

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

What is an immune response?

A

The response of lymphocytes to the presence of a foreign antigen

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

What are the types of phagocytes?

A

Neutrophils and macrophages

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

Explain what happens when pathogens invade the body.

A

Some of the cells under attack respond by releasing chemicals such as histamine

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

Explain the process of Phagocytosis.

A

-The neutrophils move towards the pathogens which are clustered together and covered in antibodies.
-The antibodies stimulate the neutrophils to attack the pathogens, this is because neutrophils have receptor proteins on their surfaces that recognize antibody molecules and attach to them.
-After the neutrophil attaches to the pathogens, the neutrophil’s cell membrane engulfs the pathogens and traps them within a phagocytic vacuole in a process called endocytosis.
-Lysosomes fuse with the phagocytic vacuoles releasing enzymes that breakdown the pathogens.

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

What is the lifespan of a neutrophil?

A

After killing and digesting some pathogens they die.
Dead neutrophils collect at a site of infection to form pus

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

What are the two types of lymphocytes?

A

B-lymphocytes (B cells)
T-lymphocytes (T cells)

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

Describe where you can find the B cells

A

They remain in the bone marrow until they are mature then they spread throughout the body.
Concentrating in lymph nodes and the spleen.

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

Describe where you can find the T cells

A

They leave the bone marrow and collect in the thymus where they mature.

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

What is the thymus?

A

It is a gland that lies in the chest just beneath the sternum. It doubles in size between birth and puberty, but shrinks after puberty.

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

Describe the immune response by the B and T cells.

A

-T cells coordinate the immune response stimulating B cells to divide and then secrete antibodies into the blood.
-The antibodies recognize the antigens on the pathogens and help destroy the pathogens.
-Other T cells find and kill any of the body’s own cells that are affected with pathogens.

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

Describe what is colonial selection?

A

When the antigen enters the body for the first time, the small numbers of B cells with their cell membrane receptors complementary to the antigen are stimulated to divide by mitosis

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

What is the primary immune response?

A

The first immune response to a specific antigen.
It is slow because there are very few B cells that are specific to the antigen.

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

What is the secondary immune response?

A

The second and subsequent immune responses to a specific antigen. It is faster because there are now many memory cells which quickly divide and differentiate into plasma cells.

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

Describe the structure of an antibody molecule

A

Each one consists of four polypeptide chains: two ‘long’/heavy chains and two ‘short’/‘light’ chains
Disulfide bonds hold the chains together

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

What is the variable region on an antibody molecule?

A

The region that forms the antigen-binding site; the amino acid sequences of the variable site form a specific shape that is complementary to a particular antigen

19
Q

What are the two types of T cell

A

T-helper cells
T-killer cells

20
Q

What is the function of T-helper cells

A

When they are activated, they release cytokines that stimulate appropriate B cells to divide, develop into plasma cells and secrete antibodies

21
Q

What is the function of T-killer cells?

A

They search the body for cells that have become invaded by pathogens and are displaying foreign antigens from the pathogens on their cell surface membranes.
They recognize the antigens attach themselves to the surface of infected cells and secrete toxic substances such as hydrogen peroxide killing the body cells and the pathogens inside

22
Q

What is active immunity ?

A

Immunity gained when an antigen enters the body, an immune response occurs and antibodies are produced by plasma cells

23
Q

What is natural active immunity?

A

Immunity gained by being infected by a pathogen

24
Q

What is artificial active immunity

A

Immunity gained by putting antigens into the body either by injection or by mouth

25
Q

What is passive immunity

A

The temporary immunity gained without there being an immune response

26
Q

What is artificial passive immunity

A

The immunity gained by injecting antibodies

27
Q

What is natural passive immunity

A

The immunity gained by a fetus when maternal antibodies cross the placenta or from breast milk

28
Q

What is herd immunity?

A

Vaccinating a large proportion of the population which provides protection for those not immunized as transmission of a pathogen is reduced

29
Q

Where are phagocytes produced and stored ?

A

In the bone marrow

30
Q

Where are macrophages located?

A

The lungs
Liver
Spleen
Kidney
Lymph Nodes

31
Q

What crucial role do the macrophages play?

A

They initiate immune responses and do not destroy the pathogens completely but cut them up to display antigen that can be recognized by lymphocytes

32
Q

Some of the activated B cells become 1._______ and others become 2._________. State the function of each of these.

A
  1. Plasma cells
    Produce antibody molecules very quickly and they secrete the antibodies into the blood, lymph or linings of the lungs and gut.
  2. Memory cells
    Remain circulating in the body for a long time if the same antigen is reintroduced a few weeks or months after the first infection, memory cells divide rapidly and develop into plasma cells and more memory cells.
33
Q

What is the function of the “hinge” region on an antibody?

A

It gives the flexibility for the antibody molecule to bind to antigens on the surface of a pathogen

34
Q

How are T-cells activated ?

A

They are activated when they recognize this antigen on another cell of the host ( the owners cells )

35
Q

What is a vaccine?

A

A preparation containing antigens which is used to stimulate an immune response artificially

36
Q

What can be used in the vaccine?

A

A whole live microorganism
A dead microorganism
A harmless microorganism (attenuated organism)

37
Q

What is a booster injection?

A

They are given after receiving less effective vaccines so that it stimulates secondary responses that give enhanced protection
It is also a good idea to receive booster shots if you are likely to be exposed to a disease

38
Q

What is ring immunity?

A

Vaccinating all those people in contact with a person infected with a specific disease to prevent disease transmission in the immediate area

39
Q

What is hybridoma?

A

A cell formed by the fusion of a plasma cell and a cancer cell, it can both secrete antibodies and divide to form other cells like itself

40
Q

How are the antibodies used in MABS produced?

A

By injecting a mouse with human fibrin (main protein found in blood clots) the mouse makes many plasma cells that secrete the antibody against fibrin. Then these plasma cells are collected from its spleen. Plasma cells are fused with cancer cells to form hybridoma that secrete the antifibrin antibody

41
Q

How are Mabs used to locate blood clots?

A

The radioactively labeled Mab is introduced to the patients blood and binds to any fibrin molecules it comes into contact with in the bloodstream. The radioactivity emitted by these labeled antibodies is used to detect where they are in the body. Then a gamma ray camera is used to detect the exact position of the antibodies in the person’s body

42
Q

What are Mabs used for?

A

To locate the position of blood clots in the body of a person though to have deep vein thrombosis
To locate cancer cells
To identify the exact strain of a virus or bacterium that is causing an infection

43
Q

How has Mabs now been developed to humanize it?

A
  1. Altering the genes that code for the heavy and light polypeptide chains of the antibodies so that they code for human sequences of amino acids rather than mouse or rabbit sequences
  2. Changing the type and position of the sugar groups that are attached to the heavy chains to the arrangement found in human antibodies