Introduction to Immunology

Question 1

Where are all the cells involved in immune system derived from?

Answer 1

Common pluripotent haematopoietic stem cell in bone marrow

Question 2

What cells fall under myeloid lineage?

Answer 2

1. Polymorphonuclear leukocytes (neutrophils, eoisinophils, basophils)
2. Dendritic cells
3. Mast cells

Question 3

What cells fall under lymphoid lineage?

Answer 3

1. B lymphocytes
2. T lymphocytes
3. Natural Killer (NK) lymphocytes

Question 4

What occurs at primary lymphoid tissue?

Answer 4

Development and maturation of B and T lymphocytes

Question 5

What occurs at secondary lymphoid tissue?

Answer 5

Mature lymphocytes encounter antigens/pathogens

Question 6

Where do ‘virgin’ B and T cells from bone marrow and thymus migrate to?

Answer 6

Specific sites in lymph nodes

Question 7

Why do lymph nodes change shape during infection?

Answer 7

In response to activation and proliferation of lymphocytes

Question 8

What is primarily found in outer layer (cortex) of lymph node?

Answer 8

B cells found in 1ary and 2ary lymphoid follicles

Question 9

What is primarily found in middle layer (paracortex)

Answer 9

T cells and dendritic cells

Question 10

What is primarily found in medullary cord (cords of lymphatic tissue)?

Answer 10

Macrophages and plasma cells

Question 11

What is the spleen?

Answer 11

Lymphoid organ in abdomen

Question 12

What is job of spleen?

Answer 12

1. Removes old and damaged erythrocytes

2. Key site of activation of lymphocytes from blood borne pathogens

Question 13

At what part of the spleen is erythrocytes removed?

Answer 13

Red pulp

Question 14

At what part of the spleen is lymphocytes stimulated?

Answer 14

White pulp

Question 15

What is the innate immune system?

Answer 15

First line of defence that is non-specific

Question 16

What are key components of innate immune system?

Answer 16

1. Mechanical barriers
2. Physiological barriers
3. Chemical mediators
4. Phagocytic leukocytes
5. Natural Killer cells

Question 17

What is stomach acid an example of?

Answer 17

Physiological barrier

Question 18

What are normal flora, mucous membranes and cilia examples of?

Answer 18

Mechanical barriers

Question 19

What is involved in humoral immunity?

Answer 19

Mediated by antibodies produced by B lymphocytes that bind to antigens

Question 20

What is involved in cellular immunity?

Answer 20

T lymphocytes recognise and destroy invading cells directly (cytotoxic cells and T helper cells)

Question 21

What are the 5 ways that the immune system can kill bacteria?

Answer 21

1. Phagocytosis by macrophages
2. Phagocytosis by neutrophils that infiltrate infected tissue from blood (stop, roll exit)
3. Complement system producing MAC
4. Opsonisation by antibodies or iC3b binding to bacterial cell surface
5. Antibodies clump together and unable to replicate

Question 22

What are the first cells to first to invading bacteria? What are their functions?

Answer 22

1. Neutrophils
   - Phagocytose pathogens
2. Macrophages
   - Phagocytose pathogens
   - Present antigens
   - Clean up cell debris after phagocytosis
3. Dendritic cells
   - Phagocytose pathogens
   - Present antigens
   - Specialised at recognising patterns on surface of foreign organisms that mark them out for generating immune response