Immune System Flashcards
First line of defence
Physical
- Skin- protective
- Nasal passages have hairs, mucous, and cilia that work as filters and trap disease causing organisms
- Stomach acids and protein digesting enzymes that destiny mucous
- Tears, saliva, and mucous destroy bacterial cell walls
Second line of defence
- First line of defence is broken
- Macrophages engulf and destroy the disease causing agent and it presents the antigen on the surface of its cell membrane
- Antigens appear on the surface of the macrophage
- The helper T cells recognize the antigen and alerts the B cells which produce antibodies to try to destroy the antigen
- Antibodies attach to the antigen and create lumps to immobilize the invader, these clumps are more easily engulfed by the macrophages
- Helper T cells also stimulate Killer T cells which destroy cells that have been invaded by viruses
- memory B cells and memory T cells are created and remain after the invading pathogen has been destroyed, they keep a blueprint of the invader in case it attacks again.
- Once the antigen has been destroyed the suppressor T cell turns off the immune response
B cells
- formed and mature in the bone marrow
- each B cell produces a single type of antibody
- Plasma cells can produce up to 2000 antibody molecules per second
T cells
-Formed in the bone marrow, mature in the thymus gland
- recognize foreign proteins on cell membrane and divides into 4 types
- memory T cells, killer T cells, helper T cells, and suppressor T cells
Memory T cells
Provide lifetime immunity, keep a blueprint of an invader should it chose to attack again
Helper T cells
Secrete proteins that activate B cells and killer T cells
Killer T cells
Destroy any infected body cells, destroy mutated cells, responsible for rejection of organs
Suppressor T cells
Shuts down immune response
antibodies
Y shaped proteins that target foreign invaders
- specific to the antigen or invader
- each antibody has a complimentary shape to its antigen, each antibody will only attach to a specific site
- Larger molecule is then engulfed by macrophages
Vaccines
-Dead or weakened pathogens injected into the body
- an exposure to the toxin allows the body to produce memory T cells and antibodies against the disease
Autoimmune disorders
- Immune system mistakenly attacks body cells
- immune system forms antibodies against healthy body tissues treating them like the antigens of invading bacteria and viruses
-white blood cells attack body organs
-Scientists believe suppressor T cells may not be working properly to suppress the WBC - some people are born with defective suppressor T cell s
