Intro to Immunology

Question 1

What is the Sequence of Immune Response 0-96h?

Answer 1

0-4h: Non-inducible Innate immunity (skin, mucosa, acidity, enzymes, lytic peptides)

4-96h: Inducible Innate immunity (complement, cytokine, phagocyte, killer cells)

> 96h: Adaptive immunity (lymphocytes)

Question 2

What are the phases of Adaptive Immunity?

Answer 2

1. Antigen recognition
2. Lymphocyte activation (clonal expansion, differentiation)
3. Antigen elimination (Humoral + cell-mediated)
4. Contraction (apoptosis to achieve homeostasis)
5. Memory

Question 3

What are the 7 features of Adaptive Immunity?

Answer 3

1. Specificity
2. Diversity
3. Memory
4. Clonal expansion
5. Specialisation
6. Contraction and homeostasis
7. Non-reactivity to self

Question 4

Where do ALL cells in immune system arise from?

Answer 4

from pluripotent haematopoietic stem cells in bone marrow

Question 5

What are the 5 types of lymphocytes?

Answer 5

1. B lymphocyte: Ab production for neutralisation, opsonisation, agglutination, complement activation by plasma cells, ADCC, mast cell degranulation
2. Helper T lymphocyte: activate T, B lymphocytes, activate M1 macrophage, inflammation
3. Cytotoxic T lymphocyte: kill infected cells
4. Regulatory T lymphocyte: suppress other T cells
5. Natural Killer cell: kill virally infected cells

Question 5

What are the cells of Immune System

Answer 5

1. Phagocytes
2. Basophil, Eosinophil, Mast cells
3. APC - dendritic cells
   4.. Lymphocytes

Question 6

How does the lymphatic system flow?

Answer 6

1. Naive lymphocytes enter lymph nodes from blood
2. Antigens from sites of infection reach lymph nodes via lymphatics
3. Lymphocytes and lymph return to blood via thoracic duct

Question 7

What is the function of the Lymph Node?

Answer 7

Lymph nodes are encapsulated, vascularised secondary lymphatic organs favouring initiation of adaptive immune responses.