Immune system 1 - MT2 - Part 1 Flashcards
How can cells communicate with each other? (3)
- Direct interaction
- Diffusible chemical communication
- Electrical signals
Why does our body need to communicate?
In order to function properly
What is an example of direct interaction communication?
Communication between an egg and a sperm cell during fertilization
- bumping into each other and recognizing them before docking and allowing fertilization to occur
What happens in diffusible chemical communication?
Allows binding of a ligand to a receptor
- could create downstream signalling cascade
What are 2 examples of diffusible chemicals?
- Neurotransmitters (small)
2. Insulin (larger)
Where does insulin come from?
Islet cells in the pancreas
What does insulin do?
It causes other cells in the body to take up glucose from the blood
What is an example of electrical signalling?
Cells in the heart passing electric current between them during a contraction cycle
- can pass electric signals onto neighbouring cells
What does the SA node do in the heart?
It initiates muscular contraction
What speed does electrical signalling occur at?
Occurs very rapidly
Pathogens
Number of individual components that communicate with each other that make up the defence that we have today
What can cause infection, but is rare because our body is good at responding?
Bacteria
What is smaller than bacteria?
Visruses
What does a virus need to survive?
A host
What do viruses not contain that bacteria does?
Ribosomes
What is one difference between viruses and bacteria?
Viruses = multicellular Bacteria = unicellular
What are 2 examples of fungi?
- Athletes foot
2. Yeast infection
Why are we typically not scared of fungi?
Because we can hand it easily
What kind of cells are protozoa’s?
Eukaryotic cells
What do protozoa’s contain?
A nucleus
What are protozoa’s more closely related to other than bacteria?
Humans
Abnormal cells/tumour cells
Are cells that continue to divide
What do abnormal cells produce?
Surface markers that our immune system cells cant recognize
Why do we have fingers?
Because before birth apoptosis occurs to separate the fingers
- similar things occurs in tadpoles
How long do RBC last?
3-4 months
What happens to RBC after they die?
They get recycled
Where do RBC get recycle? (2)
- Mainly in the spleen
2. But also in the liver
What 3 things can be handled by different branches in our defence system?
- Pathogens
- Abnormal cells
- Dead/damaged cells
What are 2 examples of nonpathogenic foreign substances?
- Pollen
- Transplanted tissues and organs
- we can tell the difference between our tissues and someone else’s
What are 2 types of defences?
- Innate
2. Adaptive
Innate (3)
- They are not keyed to individual pathogens
- They do not adapt to specific pathogens
- There is no clonal selection
What does the innate system act as?
A barrier
- eg. skin
Innate defence
Non specific defence mechanism that come into play immediately or within hours of an antigens appearance in the body
Clonal selection
It is a specific theory in immunology that explains the functions of cells (lymphocytes) of the immune system in response to specific antigens invading the body
Adaptive (3)
- They are keyed to individual pathogens
- They adapt to specific pathogens
- There is clonal selection
What does the adaptive system act like?
A castle wall
- fixed wall but the canons can move to where it is needed
What are 2 examples of the adaptive immune system?
- Antibodies
2. Cytotoxic T cells
