Immune System

Question 1

Pathogen

Answer 1

An agent that causes a disease and can enter the body in many ways

Question 2

First line of defence

Answer 2

1. Skin- protective
2. Nasal passage
3. Stomach acid
4. Tears and saliva

Question 3

2nd line of defence

Answer 3

1. First line is broken
2. Macrophages engulf and destroy the disease causing agent and it presents the entire n on the surface of its cell membrane
3. Antigens appear on the surface if the macrophage
4. The helper T cells and the antigen alerts the B cells which produce antibodies to try to destroy the antigen
5. Antibodies attach to the antigen and create lumps to immobilize the invader
6. Helper T cells also stimulate killer T cells which destroy cells that have been invaded by viruses
   7, memory B cells and memory T cells are created and remain after the invading pathogen has been destroyed
7. Once the antigen has been destroyed the suppressor T cell turns off the immune response

Question 4

B cells

Answer 4

• formed and mature in the bone marrow
• each B cell produces a single type of antibody
• plasma cells can produce 2000 antibody molecules per second

Question 5

T cells

Answer 5

• formed in bone marrow and mature in thymus gland

Memory T- provide lifetime immunity
Helper T- activate B and killer T cells
Killer T- destroy any infected body cells, destroy mutated cells
Suppressor T- shuts down immune response

Question 6

Antibodies

Answer 6

Y shaped proteins that target foreign invaders

Question 7

Vaccinations

Answer 7

Vaccinations are dead or weakened pathogens injected into the body
- it is rare that you get the same disease twice because your body has produced memory cells

Question 8

Autoimmune disorders

Answer 8

• immune system mistakenly attacks body cells