Allergy 1 Flashcards
You body creates a …
…warm, wet, nutritious environment well suited to the needs of your cells
The skin forms a…
…bag
The bag of the skin keeps…
…water in it and keeps invaders out, and nutrients.
Immune system is a diffuse…
…set of cells
Immune system has be able to detect things which are…
..foreign and affecting us negatively.
Its easier for pathogens to get in to the body via…
…the transfer epithelia
Which cells can be described as sentries?
Mast cells
Mast cells are dotted around…
…the surface of the skin (perhaps 25/mm^2)
Mast cells are chief activators of the…
…inflammatory response
Cell density of mast cells will increase in…
…chronic conditions
What are mast cells activated by?
- Immune processes
- Chemicals (Toxins, venom, cleaning products)
- Physical injury (trauma, temperature extremes, uv radiation)
Mast cells contain many…
…granules
Mast cells contain many granules containing…
…signal molecules
On activation, mast cells …
…degranulate releasing signal
molecules including histamine
On activation, mast cells degranulate releasing these signal
molecules including histamine
* This, along with any cellular damage,
results in…
…the inflammation of the surrounding tissue and the accompanying symptoms
Damaged tissues and
mast cells release …
…histamine, increasing the blood flow to the area
Histamines cause capilleries to…
…leak, releasing phagocytes and clotting factors into the wound.
Phagocytes engulf…
…bacteria, dead cells, and cellular debris
Platelets move out of…
…the capillary to seal the wounded area.
The acute inflammatory response is caused by…
…mast cell degranulation and release of cellular contents
What are the causes of inflammation?
- Redness
- Swelling (edema)
- Heat
- Pain
Why does redness cause inflammation?
due to increased blood flow to the area of injury
Why does swelling cause inflammation?
due to increased extra-vascular fluid and infiltration of immune cells (phagocytes) into the damaged area (later forms pus).
Why does heat cause inflammation?
due to the increased blood flow and the action of fever-inducing agents
(pyrogens).
Why does pain cause inflammation?
caused by local tissue destruction and irritation of sensory nerve (pain)
receptors.
What are the functions of inflammation?
- Destroy and remove unwanted substances
- Wall off infected & inflamed area from the rest of the body
- Stimulates the immune response
- Promotes healing by removing damaged tissue
What are the most numerous white blood cells in the body?
Neutrophils, which are the killers.
Neutrophils eat…
…micro-organisms and spray the area with oxidants such as hydrogen peroxide
Neutrophils die in such numbers that they…
…form the white sticky substance we call pus
Neutrophils and other immune cell types also send…
…signals to the rest of the system for help
Neutrophils and other immune cell types also send signals to the
rest of the system for help.
- Theses are in the form of a family of hormones called…
…cytokines
Neutrophils and other immune cell types also send signals to the
rest of the system for help
- Theses are in the form of a family of hormones called cytokines
- In particular they are a sub-group called…
…pro-inflammatory cytokines (PICs).
(IL1, TNFa, IL6)
Rising levels of PICs lead to…
- Fever
- Nausea
– Loss of appetite
– Weakness/lethargy
– Hyperalgesia (sensitivity to pain)
– Headache
– Social withdraw/lack of concentration
When neutrophils produce their toxic secretion they have an increased need for…
…oxygen
When neutrophils produce their toxic secretion they have an increased need for oxygen.
* It is thus called the…
…oxidative burst
one of the major components of the
exudates is…
…oxidants
Hydrogen peroxide is great for…
- Great for killing invaders
- Great for cleaning wounds
- But you want it to stop here
- Because it is…
- Great for oxidising cholesterol
- Great for mutating DNA
- Great for killing health tissue
The adaptive immune system tags…
…perceived threats so that other members of the immune system can deal with it.
The tag (in the adaptive immune system) is called …
…an antibody or immunoglobulin.
- Its a protein
The adaptive immune system can be …
…very selective and thus efficient and so can minimise damage to the body.
The immune system produces…
… antibodies that recognise every single structure possible (about 1 billion combinations)
The immune system produces antibodies that recognise every single structure possible (about 1 billion combinations).
This causes another problem…
… It will produce antibodies that will be able to recognise its own cells as well as essential things like food items.
Antibodies are produced by cells termed…
…B-cells
- (B for bone marrow, because this is where they are educated on
what is self and what is not)
B-cells leave the …
…bone marrow, and sits around in tissues until needed.
B-cells leave the bone marrow and sit around in tissues until needed.
* At this point they are called…
…naïve or virgin B cells
Virgin B cells display their antibody
on…
…their surface
The first thing needed to activate Virgin B cells is for more than one antibody to …
…bind the complementary antigen
- This tells the cell that the binding
is not by accident
For virgin B cells to be fully active, a…
…second stimulus is needed.
To be fully active a second stimulus is needed.
* This is done by…
… interaction with a ‘helper T cell’
The helper T cell effectively
confirms that …
…the body is at war to the B cell
Cells called T helper cells instruct the B cell on…
…what type of enemy it faces
Cells called T helper cells instruct the B cell on what type of enemy it faces.
* The B cell responds by…
…changing the form of the antibody it
produces.
What are the 5 types of antibody?
- IgM
- IgD
- IgA
- IgG
- IgE
Whats IgM?
virgin type
Whats IgD?
non functional?
Whats IgA?
secreted
Whats IgG?
blood
Whats IgE?
skin
Whats the most common form of antibody?
IgA
IgA is found in all…
…secretions, including mothers milk and gastrointestinal tract.
The job of IgA is to…
…neutralise the invader before it actually gets in
IgE is found in the…
…skin.
IgE is found in the skin mainly attached to…
…mast cells.
What does IgE defend against?
- Defends against big things like parasites entering
So if the IgE detects a worm tries to burrow into the skin, then the…
…mast cell induces inflammation
- The worm is exposed to a cocktail of toxins including hydrogen peroxide.
IgG is found in the…
…blood and others places where there is fluid, such as interstitial fluid.
IgG counters infections that are…
…systemic
How does IgG deal with systemic infections?
small micro-organisms so each one has to be tagged and dealt with.
WHats the most common internal antibody?
IgG
What are the two main forms of T helper cell?
Th1 cells and Th2 cells
Th1 cells indicate that…
… the infection is in the tissues and directs the B cells to produce IgG antibodies.
(To cover the internal spaces)
Th2 cells indicate that…
… the infection is on the surface and so directs the B cell to make either IgA or IgE.
(To guard mucosal membranes and the skin)
The last decision a B cell has to make is…
…whether it will now become a plasma or a memory cell
Plasma cells go on to…
…divide and secrete their antibodies
Memory cells hide away quietly remembering …
…the signs and signals of the war they were in.
Memory cells hide away quietly remembering the signs and signals
of the war they were in.
* If those signs and signal reappear then …
…they quickly activate.
- This means it is a lot quicker to start the immune response again.
