Foundations Of Immunology

Question 1

What are the 2 kinds of immunity?

Answer 1

Innate and Adaptive

Question 2

What does innate immunity do and how can it be flawed?

Answer 2

Doesn’t distinguish between pathogens but recognises them and acts immediately. Some microbes develop immunity

Question 3

How does adaptive immunity work? How long does it take to develop?

Answer 3

Distinguishes between pathogens and using antigen markers. Few days to remember but produce memory cellls

Question 4

What are the three phagocytes and their purpose?

Answer 4

Neutrophils, Monocytes, Macrophage. Engulf and digest pathogens and our own dead cells

Question 5

What is the role of neutrophils?

Answer 5

They are granulated cells. When a microbe attaches to them, it undergoes endocytosis and forms a phagosome. The granule filled lysosome in the cell fuses with the phagosome and the granules enzymes kill the microbe. The waste is secreted by exocytosis

Question 6

What are Eosinophils and their role?

Answer 6

Help us combat parasitic infections, allergy and asthma. Have acid granules and enzymes.

Question 7

What are mast cells?

Answer 7

Has histamine as granules and has IgE receptor which binds to allergens, causing histamine to be released and cause an allergic reaction.

Question 8

What are basophils?

Answer 8

Least common WBC. No proven function but have granules which are inflammatory mediators and found near site of infection.

Question 9

What are cytokines?

Answer 9

Proteins secreted by cells under specific stimuli. Communicate many biochemical processes. Important in innate and adaptive immunity

Question 10

What are the primary lymphoid organs and what happens there?

Answer 10

Thymus and bone marrow. T-cells mature in the thymus (receive receptor). Hematopoeisis occurs in bone marrow

Question 11

What are the secondary lymphoid organs and what do they all do?

Answer 11

Lymph nodes, spleen, tonsils and mucosal immune system. The sites of lymphocyte action

Question 12

What are the two lymphocytes?

Answer 12

B and T cells

Question 13

What occurs at the lymph nodes?

Answer 13

Over 500 in our bodies. Connected by lymph vessels which transport WBC’s. Acts as a filter to eliminate waste from lymph fluid

Question 14

What occurs in the spleen?

Answer 14

150g fist shaped organ which filters blood and produces leukocytes to fight germs in blood

Question 15

What are the 2 T-Lymphocytes and their overall function (2)?

Answer 15

Cytotoxic T cells and T-Helper cells. Responsible for cell-mediated immunity and assisting B-cells

Question 16

Which receptor does cytotoxic T Cells have and how do they function?

Answer 16

CD8+ receptor. Recognises antigens bound to MHC1 and kills abnormal cells directly

Question 17

How do cytotoxic T Cells kill abnormal/foreign cells?

Answer 17

Once CD8+ has bound to the antigen, perforin form holes in the abnormal cell, and granzymes enter via the holes and induce lysis.

Question 18

How do T-Helper cells work?

Answer 18

They have CD4+ receptors which bind to cells with MHC11 attached. They bind to B Cells and release cytokines to activate B-Cells.

Question 19

What are the 4 T-Helper cell types and their functions?

Answer 19

All produce different cytokines for varying situations. TH1 (activate macrophages), TH2 (eosinophils and mast cells), TH17 (mast cells) and Tfh (activate b-cells)

Question 20

Role of B-Lymphocytes + where are they found?

Answer 20

Produced and mature in bone marrow. Differentiate into memory cells and plasma cells, which generate antibodies specific to pathogen.

Question 21

What is an antigen?

Answer 21

Any substance that can trigger an immune response.

Question 22

What is an antibody/immunoglobulin?

Answer 22

A protein produced as an immune response. They have a Y shaped structure which binds to antigens

Question 23

What are the 5 classes of Immunoglobulin?

Answer 23

IgA, IgE, IgD, IgM, IgG

Question 24

Where can IgA be found, its role and its structure?

Answer 24

Saliva, tears, mucus, breast milk. Involved in neutralisation. 1-4 Y -antibodies

Question 25

Where is IgG found, what does it do and it’s prominence?

Answer 25

Found in blood and ECF, controlling infection. Makes up 75% of total antibodies

Question 26

Where is IgD found and its function?

Answer 26

Found on B cell as receptor - activates B-Cell

Question 27

What are the three mechanisms of antibody protection?

Answer 27

Neutralisation, opsonization and the complement system

Question 28

What is neutralisation?

Answer 28

Antibodies (in particular IgA) binding to pathogens, preventing attachment to cell surfaces.

Question 29

What is opsonization?

Answer 29

Antibodies facilitating the uptake of pathogens by phagocytosis

Question 30

What is the complement system and where does it occur?

Answer 30

Group of proteins act as a domino effect that leads to production of membrane attack complex on target cells, and destroys them. Takes place on the surface of target cells./

Question 31

What roles do the products of the complement system partake? (2)

Answer 31

Some products increase blood flow and recruit other WBC’s (neutrophils and macrophages) to the site to enhance the immune response. Some products also induce opsonization

Question 32

Active vs Passive immunity

Answer 32

Active is when an individuals own immune system is involved with producing antibodies. Passive is when antibodies have been inserted into an individual to induce immunity. E.g. vaccines

Question 33

IgM role

Answer 33

Involved in early immune response. Activate the complement system

Question 34

What are platelets formed from?

Answer 34

Megakaryocytes