Introduction to Immunology

Question 1

What are the two major branches of the immune system?

Answer 1

Innate and Adaptive

Question 2

What are the main features of the innate response?

Answer 2

It is the first responder and is a physical and chemical system. It is capable of rapid responses and is destructive and has no memory.

Question 3

What are the main features of the adaptive response?

Answer 3

It can recognize antigens and has a specific memory of them. It can also distinguish with high precision between self and foreign.

Question 4

What is the initial barrier to infection?

Answer 4

Skin and mucosa

Question 5

What can skin make as a response to breach to mitigate the effect of infection?

Answer 5

Defensins, which are antimicrobial peptides

Question 6

What are the innate defense strategies used by mucosa?

Answer 6

They range from mucus that can trap invaders, constantly beating cilia that eject particles from the lung to very low pH in gastric secretions, the vagina and urine.

Question 7

How do innate immune cells detect danger?

Answer 7

They do so by sensing molecular patterns unique to microbes or damaged cells.

Question 8

What are the molecular patterns that are recognized by innate immune cells called?

Answer 8

Pathogen-associated molecular patterns (PAMPs)

Damage -associated molecular patterns (DAMPs)

Question 9

What receptors are used to detect the PAMPs and DAMPs?

Answer 9

TOLL Like Receptors (TLR)

Question 10

What is activated as the PAMPs and DAMPs bind to the TLRs?

Answer 10

Phagocytic and killing mechanisms of the cell

Question 11

What are the two pathways that innate immunity uses to deal with danger detection?

Answer 11

• Circulating proteins

- Immune effector cells

Question 12

What is the role of leukocytes in innate immunity?

Answer 12

They are characterized by the ability to respond rapidly and in large numbers.

Question 13

What about leukocytes allows them to perform their function and why may this be harmful to the host?

Answer 13

Their cytoplasm contains granules that are loaded with killer/hydrolytic/oxidizing molecules that are released in response to a perceived threat. The released chemicals cannot discriminate between tissues and pathogens.

Question 14

What is used as the method of communication between the innate and the adaptive systems?

Answer 14

Cytokines (two chain polypeptides encoded by different genes and their polymorphism allows for variety in communication)

Question 15

What is a common antigen that is recognized by the innate system?

Answer 15

Mannose

Question 16

What is the relationship between the innate and the adaptive immune system?

Answer 16

The innate system defends the host while the adaptive response prepares its defense.

Question 17

What is the main cell of the adaptive system?

Answer 17

Lymphocyte.

Question 18

What are some of the properties of the lymphocytes?

Answer 18

• Has specific antigen receptors

- Communicates with other cells by cytokines and receptors

Question 19

What are the two types of lymphocytes?

Answer 19

B Cells

T Cells

Question 20

What is the function of B cells?

Answer 20

B cells differentiate into plasma cells that can produce highly specific antibodies that bind to pathogens and can destroy them by several mechanisms

Question 21

What is the function of T cells?

Answer 21

T cells that have helper and killer functions. These cells also regulate the immune response by controlling cytokine production

Question 22

Which of the immune systems is faster?

Answer 22

Innate

Question 23

Which of the immune systems is more specific?

Answer 23

Adaptive

Question 24

Which of the immune systems has memory?

Answer 24

Adaptive

Question 25

What is the ON switch for the activation of an innate response?

Answer 25

Activation of the TLR

Question 26

What is the most common leukocyte in the blood?

Answer 26

Neutrophils

Question 27

What is the function of eosinophils?

Answer 27

They are closely related to neutrophils but have specialized granules that were originally developed to drill holes in large parasites like worms. Over time they have become pathologic mediators of several types of allergic reactions.

Question 28

What is the function of the basophils and mast cells?

Answer 28

Basophils and Mast cells are the least common leukocytes found in peripheral blood. These cells can act as antigen presenting cells and also have specialized granules and receptors that are important in specialized antibody reactions and parasite defense.

Question 29

What is the function of the monocyte and macrophage?

Answer 29

Eating and breaking down of of foreign cells

Question 30

What is the function of dendritic cells?

Answer 30

They are the sentinel cells of the immune system and the critical cell that activates the adaptive system.

Question 31

What is the function of natural killer cells?

Answer 31

Natural Killer Cells (NK) are large granular lymphocytes that most likely developed in response to the debut of viruses in the scheme of things. Although they contain granules, they are usually called lymphocytes, not granulocytes.