Lecture 40

Question 1

What is the immune system?

Answer 1

An organised system of organs, cells and molecules that interact together to defend the body against disease e.g pathogens

Question 2

What are the main features of the lymphatic system?

Answer 2

• Primary organs
• –> makes white blood cells - lymphocytes
• Secondary organs
• —> sites where immune responses are intiated

Question 3

What are the primary lymphoid organs?

Answer 3

Thymus
- school for T cells
- developing T cells learn not to react with self
Bone Marrow
- source to stem cells that develop into cell of the innate &; adaptive immune system

Question 4

What are the secondary lymphoid organs?

Answer 4

Lymph nodes
- located along lymphatic vessel
-lymph fluid from blood and tissue is filtered
Spleen —–> blood-borne pathogens

• both are sites were immune responses are initiated

Question 5

What are the three layers of defences?

Answer 5

1) Physical & Chemical barriers
2) Arm 1: innate immune system
3) Arm 2: adaptive immune system

Question 6

Describe arm 1: the innate immune system

Answer 6

• already in place
• rapid response: mins-hours of infection taking place
• Fixed
• non-specific - TLR’s
• no memory

Question 7

Describe arm 2: the adaptive immune system

Answer 7

• improves during response - flexible
• slow response: hours - days
• Variable
• Specific
• has memory

Question 8

What are the major discoveries of immunology?

Answer 8

• Variolation –> purposeful controlled infection
• Vaccination –> cowpox sore gives immunity to small pox
• Phagocytes
• Antibodies

Question 9

What cells are part of the innate immune system?

Answer 9

Phagocytes = neutrophils, macrophages, monocytes and dendritic cells
- NK cells

Question 10

What molecules are part of the innate immune system?

Answer 10

• Antimicrobial peptides
• Complement
• Type 1 interferon

Question 11

What do antimicrobial peptides do?

- innate immunity

Answer 11

• interfere with growth and reproduction

- chemoattract –> produce chemicals that attract other cells

Question 12

What do type 1 interferons do?

- innate immunity

Answer 12

• is cytokine —-> signalling molecule
• released by infected to cells which signal neighbouring cells to apoptosis “cell suicide” or reduce protein synthesis & destroy DNA

Question 13

What do complement proteins do?

Answer 13

Are inactive proteins which circulate around the body, once triggering occurs ( 3 pathways) 3 outcomes occur - triggers complement cascade