Immunology

Question 1

What is the general function of white blood cells?

Answer 1

To provide a fast defence against any infectious agent

Question 2

How many are generally in an average person

Answer 2

~7000/microL

Question 3

What is diapedesis

Answer 3

the movement of WBC into tissues from the blood stream

Question 4

What molecules allow diapedesis to occur? (2)

Answer 4

Secretin and adhesion cells. They relax pores to allow WBCs through

Question 5

Where are the selectins for diapedesis present?

Answer 5

Veins, not arteries

Question 6

How long do granulocytes circulate in the blood and in the tissue?

Answer 6

Blood: 4-8 hours
Tissue: 4-5 days

Question 7

What do monocytes differentiate into?

Answer 7

Macrophages, they increase in size 5x

Question 8

How long do macrophages live in the tissue?

Answer 8

Months

Question 9

How often do lymphocytes enter the circulation?

Answer 9

Continuously

Question 10

How long can lymphocytes live?

Answer 10

Months or years, depends on the individual’s need for them

Question 11

What 3 systems do lymphocytes circulate between?

Answer 11

1. Blood
2. Lymphatic system
3. Tissue

Question 12

What are the 3 kinds of granulocytes?

Answer 12

1. Neutrophils
2. Eosinophils
3. Basophils

Question 13

What are the most abundant leukocytes in the blood? Why is this important?

Answer 13

Neutrophils, they are usually the first defensive cell type to be recruited to an infection site (chemotaxis)

Question 14

How do neutrophils work?

Answer 14

They neutralize fungi or bacteria via phagocytosis

Question 15

What do eosinophils respond to? How do they destroy the issue?

Answer 15

Parasitic infection: release things like hydrolytic enzymes to weaken or destroy parasite
Detoxification of inflammatory substances: release H2O2

Question 16

Where are basophils and mast cells located

Answer 16

basophils are in the circulation and mast cells are in tissue

Question 17

What is the function of mast cells?

Answer 17

produce heparin to prevent coagulation and help with the removal of fate cells

Question 18

What do basophils and mast cells do together?

Answer 18

Release histamine, bradykinin, and serotonin. This increases the “leakiness” of endothelial water and can cause swelling an pain. Mediated by IgE, which is involved in the allergic response.

Question 19

What are the 2 functional forms of the immune system?

Answer 19

1. The innate immune system - 1st line of defence

2. The adaptive (acquired) immune system - better with repeated infection. Specific.

Question 20

What are the 5 chemotactic factors?**

Answer 20

1. Some bacterial factors
2. Degenerative products of inflamed cells
3. Complement complex
4. Specific factors (cytokines secreted by host or the invading cells)
5. Foreign membrane protein triggering leukocytes

Question 21

What is involved in the innate immune system?

Answer 21

1. Physical and physiological (pH, temp, etc) barriers
2. Soluble compounds (lysozyme, cytokines, etc)
3. Cellular components

Question 22

What are physical and physiological barriers found in the first line of defence?

Answer 22

Physical - skin

Physiological - pH, temperature, oxygen tension (limits microbial growth)

Question 23

What are lysozymes?

Answer 23

Enzymes that attack the bacterial cell wall. (macrophages and neutrophils)

Question 24

What is the function of a C-reactive protein?

Answer 24

• Promotes opsonization
• Allows recognition of bacteria by macrophages
• Binds to the surface of damaged bacterial cells; promotes the activation of the complement system

Question 25

What is the function of C1?

Answer 25

It is initiated by the Ag Ab complex, and when it is activated it activated the C4 + C2 complexes

Question 26

What is the function of C3b?

Answer 26

It promotes opsonization of bacteria, and activates mast cells and basophils

Question 27

What is the function of C5a

Answer 27

It activates mast cells and basophils. It also promotes chemotaxis of white blood cells

Question 28

What are the two pathways used to activate the complement complex system?

Answer 28

1. The classical pathway - activated by antibody-antigen complexes 2. The alternative pathway - binding of complements to surface molecules of pathogens

Question 29

How are cytokines involved in the immune response?

Answer 29

After an infection, macrophages are activated which active cytokines. When cytokines are activated they increase the production of granulocytes, monocytes, and lymphocytes.

Question 30

What are the 2 cellular components of the first line of defence?

Answer 30

1. NK cells (natural killer cells) | 2. Phagocytic cells (macrophages and polymorphonuclear leukocytes)

Question 31

How do NK cells work?

Answer 31

Activated by interferons. They are lymphocytes that recognize changes on the cell surface when they are infected by viral proteins, the also recognize foreign cells and tumour cells. Bind and kill

Question 32

What are the 2 types of phagocytic cells in the first line of defence?

Answer 32

1. Neutrophils | 2. Macrophages

Question 33

What is opsonization?

Answer 33

When compounds are deposited (complement C3b, or an antigen) on an infectious agent. It increases the binding of a phagocyte to help destroy infecting cells.

Question 34

What is the reticuloendothelial system?

Answer 34

A network of macrophages and neutrophils in a high concentration in many organs such as the bone marrow, spleen, lymph nodes, skin, liver, and alveoli.

Question 35

In general, what is the adaptive immune system?

Answer 35

The learned aspects that has acquired mechanisms to defend against specific invading agents. It works together with the innate immune system

Question 36

What are antibodies?

Answer 36

Gamma globulins. Composed of 2 heavy chains and 2 light chains

Question 37

What is fab?

Answer 37

Fragment antigen binding. This is the antigen binding region that varies in different antibodies to allow specific binding of an antigen. Can only bind to one part of the molecule called the antigenic determinant domain or the epitope

Question 38

Where is the fc on an antibody?

Answer 38

This is the fragment crystalline which is similar in most antibodies and can bind to host tissue and complements after Ab binds to Ag.

Question 39

What are the 5 classes of Ig?

Answer 39

1. IgG - major antibody (70-75%) in 2nd immune response, exclusive to anti-toxin class 2. IgA - (15-20%) involved in sero-mucous secretion (in milk to give baby more immunity) 3. IgM - (~10%) pentameric, an early antibody against antigenically complex organisms 4. IgD - (~1%) major form of the membrane of B-lymphocytes 5. IgE - on the surface of basophil and mast cells, involved in parasitic response, inflammatory, and allergic reactions