inflammation Flashcards
Define inflammation.
A local physiological response to tissue injury.
how is inflammation classed x2
acute
chronic
summary of acute inflammation
1- initial reaction of tissue to injury
2- vascular component- dilation of vessels
3- exudative component, leakage of protein rich fluid
4- neutrophil is the first cell at the scene
5- outcome may be resolution, suppuration, organisation or progression to chronci
what cells are involved in inflammation 5
neutrophil polymorphs
* Macrophages
* Lymphocytes
* Endothelial cells
* Fibroblasts
what is chronic inflammation
Slow onset or sequel to acute
– Long duration
– May never resolve
Causes of acute inflammation
Microbial infections
Hypersensitivity reactions
Physical agents
Bacterial toxins
Characteristics of neutrophil polymorphs
Short lived cells
* First on the scene of acute inflammation
* Cytoplasmic granules full of enzymes that
kill bacteria
* Usually die at the scene of inflammation
* Release chemicals that attract other
inflammatory cells such as macrophages
characteristics of macrophages
Long lived cells (weeks to months)
* Phagocytic properties
* Ingest bacteria and debris
* May carry debris away
* May present antigen to lymphocytes
characteristics of lymphocytes
Long lived cells (years)
* Produce chemicals which attract in other
inflammatory cells
*produces memory cells from past infections
what to endothelial cells produce that stops things from sticking
nitrous oxide
why does an inflamed area look red and swollen
capillaries are open
swollen as it has more blood and fluid
what does sepsis look like
all blood vessels are open,
not enough blood to fill them
characteristics of fibroblasts
-Long lived cells
-Form collagen in areas of chronic
inflammation and repair
-spindle shaped
what is a granuloma
An aggregate of epitheloid histocytes
best known chemical mediator in acute inflammation
histamine
what does histamine do
- causes vascular dilation
-increases vascular permeability
what is the role of mast cells
- On stimulation by c3a/c5a complement components they release preformed inflammatory mediators
-metabolise arachidonic acid into newly synthesised inflammatory mediators
what is a prostaglandin
chemical mediator of inflammation
5 cardinal signs of inflammation
- Redness (rubor).
- Swelling (tumor).
- Pain (dolor).
- Heat (calor).
- Loss of function.
define exudate
fluid that leaks out of vessel walls due to increased vascular permeability
what are the benefits of exudate formation
-dilution of toxins
-entry of antibodies
-transport of drugs
-fibrin formation
what are the 4 systemic effects of acute inflammation
- Fever.
- Feeling unwell.
- Weight loss.
- Reactive hyperplasia of the reticuloendothelial system
What are the 4 outcomes of acute inflammation
- Resolution.
- Suppuration- formation of pus
- Organisation (scar tissue formation).
- Progression onto chronic inflammation.
what is resolution
initiating factor removed
tissue undamaged or able to regenerate
what is repair
-initiating factor still present
tissue damaged and unable to regenerate
what is suppuration
formation of pus, a mixture of living, dying and dead neutrophils and bacteria
what is organisation
the replacement by granulation tissue as part of the process of repair
Give 4 causes of chronic inflammation.
- Primary chronic inflammation.
- Transplant rejection.
- Recurrent acute inflammation.
- Progression from acute inflammation.
sequence of chronic inflammation
either progression from acute inflammation or starts as
‘chronic’ inflammation such as infectious mononucleosis
* no or very few neutrophils
* macrophages and lymphocytes, then usually fibroblasts
* can resolve if no tissue damage (e.g. viral infection like
glandular fever) but often ends up with repair and formation of scar tissue
what is healing by 2nd intention
when you cant get the edges of skin together
so the wound will be left open to heal naturally
may be due to excess trauma
why does repair occur
when tissue damage occurs where tissue can’t regenerate
what cells do not regenerate
- myocardial cells
- neurones
Names of the 4 stages of neutrophilic action
/Margination
Adhesion
Emigration
Diapedesis
Describe the 4 stages of neutrophilic action
Migration - increase in plasma viscosity , neutrophils line up along plasmatic zone
Adhesion to neutrophils - adhesion to vascular endothelium occurs and attach
Emigration - neutrophils pass through endothelial cells onto vessel wall
Diapedesis- rbcs may also escape from vessels , indicates severe vascular injury
What conditions might you see a granuloma
TB, LEPROSY
chrons
Sarcoodosis
What are some macroscopic features of chronic inflammation
Chronic ulcer
Chronic abscess activity
Granulomatous inflammation
Fibrosis
The activity of what enzyme in the blood can act as a marker for granulomatous disease
ACE
You suspect a patient has sarcoidosis which blood marker do you investigate
ACE - released by granulomas
What is resolution
The complete restoration of tissues to normal
Minimal cell death
What is suppuration
Formation of pus
Becomes surrounded by pyogenic membrane
What is organisation
Replacement by granulation tissue
New capillaries grow into the inflammatory exudate
What is progression
Causative agent is not removed so there is progression to chronic inflammation
what is the name of the cell that produces collagen in fibrous scarring
fibroblasts
appendicitis is an example of ?
acute inflammation
crohns disease is an example of ?
granulomatous inflammation
Benefits on inflammation
Destruction of invading microbes
Harmful effects of inflammation
Digestion of normal tissues
Swelling
Inappropriate inflammatory response
what is the role of mast cells
- On stimulation by c3a/c5a complement components they release preformed inflammatory mediators
-metabolise arachidonic acid into newly synthesised inflammatory mediators
