Basic concepts

Question 1

What is an inappropriate response in the immune system?

Answer 1

Sepsis (overreaction), Allergy and asthma (oversensitive), Chronic inflammatory disorders (no resolution).

Question 2

What are examples of autoimmune diseases?

Answer 2

Diabetes type I, multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus.

Question 3

What are the types of immunodeficiencies?

Answer 3

Primary (genetic) (Severe Combined Immunodeficiency), Secondary/acquired (AIDS, from HIV infection).

Question 4

What is the innate immune system?

Answer 4

The body’s first line of defense, involving nonspecific responses to pathogens.

Question 5

What is the adaptive immune system?

Answer 5

Tailored immune responses involving B and T cells, with memory of previous infections.

Question 6

What are the primary lymphoid organs?

Answer 6

Bone marrow (generation of leukocytes) and thymus (maturation of T-cells).

Question 7

What are the secondary lymphoid organs?

Answer 7

Where mature lymphocytes meet antigens, including lymph nodes, spleen, and MALT.

Question 8

What are the primary organs of the immune system?

Answer 8

Bone marrow, Thymus gland.

Question 9

What are the secondary organs of the immune system?

Answer 9

Spleen (filters blood), Lymph nodes (filter lymph), MALT (Peyer’s patches, tonsils, appendix).

Question 10

What are hematopoietic stem cells (HSCs)?

Answer 10

Found in bone marrow, HSCs constantly renew and differentiate into progenitor cells.

Question 11

What is an important first line defense in the immune system?

Answer 11

Cells that express granules with proteases, antimicrobial proteins, etc.

Question 12

What are neutrophils?

Answer 12

Phagocytic and bactericidal, first at infection site but short-lived.

Question 13

What is the role of basophils/mast cells?

Answer 13

Involved in inflammation and allergic responses.

Question 14

What do eosinophils do?

Answer 14

Kill antibody-coated parasites.

Question 15

What are myeloid cells?

Answer 15

Granulocytes (neutrophils, eosinophils, basophils), Monocytes and macrophages.

Question 16

What happens to blood monocytes?

Answer 16

Migrate to tissues, differentiate into macrophages, arrive later than neutrophils but live longer.

Question 17

What are dendritic cells?

Answer 17

Heterogeneous, phagocytic antigen-presenting cells, link innate and adaptive immunity.

Question 18

What are T cells in the adaptive immune system?

Answer 18

Develop in thymus, express rearranged T-cell receptors (TCR), involved in clonal selection.

Question 19

What are T-cell effector cells?

Answer 19

T helper cells (CD4+), T cytotoxic cells (CD8+), and memory cells.

Question 20

What are B cells in the adaptive immune system?

Answer 20

Express rearranged B-cell receptors (BCR), act as antigen-presenting cells.

Question 21

What are B cell effector cells?

Answer 21

Plasma cells that release antibodies, memory cells.

Question 22

What occurs in secondary lymphoid organs?

Answer 22

Sites where lymphocytes meet antigens, expand clonally, and differentiate into effector and memory cells.

Question 23

What is the pattern recognition in innate immune cells?

Answer 23

Have germ-line encoded pattern-recognition receptors (PRRs) for microbial patterns and damaged self.

Question 24

What do PRRs do?

Answer 24

Signal to activate the cell and initiate effector functions: Phagocytosis, cytokine secretion, chemokine release, antimicrobials, and inflammation.

Question 25

What is clonal expansion in adaptive immune cells?

Answer 25

B and T cells with specific receptors recognizing antigens; clonally expand and mature into effector cells.