The inflammatory response

[Asguard]

Not sure how many people will actually know the answer to this because im after an answer down to the cellular level

2 questions

1) why is the inflamitory responce helpfull when it seems to be the major cause of the body going into shock

2) how does it actually work on the celular level

 

[S.A.M.]

The primary physiological reasoning behind the inflammatory response is to increase the blood flow to the affected region. (sort of like calling in the SWAT team).

In particular, the blood vessels around the site of inflammation dilate, allowing increased blood flow to the area. Gaps appear in the cell walls surrounding the area, allowing the larger cells of the blood, i.e. the immune cells, to pass through. As a result of the increased blood flow, the immune presence is strengthened. All of the different types of cells that constitute the immune system congregate at the site of inflammation, along with a large supply of proteins, which fuel the immune response. There is an increase in body heat, which can itself have an anti-biotic effect, swinging the balance of chemical reactions in favour of the host. The main symptoms of the inflammatory response are as follows.

* The tissues in the area are red and warm, as a result of the large amount of blood reaching the site.

* The tissues in the area are swollen, again due to the increased amount of blood and proteins that are present.

* The area is painful, due the expansion of tissues, causing mechanical pressure on nerve cells, and also due to the presence of pain mediators.

Once the inflammatory process has begun, it continues until the infection that caused it has been eradicated. Phagocytes continue to consume and destroy bacteria, the acquired immune system binds and disposes of harmful toxins. Pus is produced, pus being the debris that is left over from the battle between the invader and the immune system. The colour of the pus depends on the organism causing the infection.

If its an area that is protected by the macrophages, they will immediately ingest the particles and present them as antigens to activate cells that form antibodies to the antigens as well as phagocytes that destroy the foreign bacteria etc. They also recruit other cells from the immune system. Without the immune system, the slightest cold could kill you. You'd have to live in a bubble.

More:
http://en.wikipedia.org/wiki/Inflammation

 

[Asguard]

Ok this makes sence so why does it get out of control in shocked pts? (not talking about auto imune disease)

For example in septic shock the vasodilation goes on to the point where the red blood cells circulating arent enough to perfuse the whole body (epecially the heart, kidneys and brain) because the BP drops, heart rate goes up to compensate but the Cadiac output isnt enough to compensate for the drop (which is why BP goes down) and the pt can go into iriversable shock

Then there is anaphlactic shock which has the added complication of occuliding the airways as well as droping the BP

The one that baffles me the most however is the increased relace of heprin in hypovalimic shock, this doesnt make any sence as its compleatly counter productive when platelts should be slowing the bloodflow to increase it

Im sorry if these are stupid questions

 

[S.A.M.]

Hmm, too much homework?

Septic shock: the vasodilation is caused by endotoxins usually by gram negative bacteria

anaphylactic shock: is an allergic reaction, not a normal response. Abnormal responses are unpredictable.

hypovolemic shock: hypo (low) volemia (volume) is due to loss of fluid due to injury (burns) or blood loss. Heparin is an anticoagulant and I would assume that treatment with heparin may cause hypovolemic shock. Don't know that it causes increased release of heparin though.

 

[Asguard]

i could be barking up the wrong tree here

I AM trying to combind what i have learnt in multiple classes on different topics (one of which was 2 years ago)

I had to take a year off because of anxiaty and so im trying to preserve what i already knew and combind it with what SHOULD have been the next topic

 

[S.A.M.]

The immune response is what happens in the case of injury or infection. Being complex and diverse, it is prone to tweaks and hijacks much like any other system. Aberrations and abnormalities do not make the system less desirable.

 

[Varda]

i aced my imulology class in univ, but that was a long long time ago, let's see what I can remember

the imune system works mainly in two fronts, one is humoral and one is celular

when the organism is exposed to an antibody, it instantly triggers the humoral response, which is also know as the complement factor or the complement system

the complement system is a chain of reactions starting with the antibody and which produces a series of proteins which have several functions, from stimulating the celular response, to producing the membrane attack complex, which is a tubular protein that wrecks shit

anyway, some of these proteins, c3 and c5 if i remember correctly, have anaphilatoxin activity. this activity is responsible for the degranulation of basophiles, which is the body's most important defense agains parasites.

so, basicaly when an antibody is capable of generating a huge amount of these proteins in the body, that causes a very strong degranulation, and the consequence of that is major vasodilation and bronchial constriction caused by edema... shock

to make it simple, shock is an exagerate response from your imune system, to an antibody that you are extremely sensitive to. These substances are there to help you, and they do every day, but sometimes they just go way over the top

read up on the complement system, it's really interesting

 

[Vkothii]

Also the MHC genes, and bacterial flagella, there's a link there, apparently; and the immune signalling cascades. The immunoglobulins are one of the most studied sets of proteins in biology/medicine.

But take it in bite-sizes, it's a really big subject, the immune response alone, and how immunity "forms", from what is essentially proteins "joining together".