Inflammation process Flashcards
What is inflammation?
Localized, protective response to tissue injury design to destroy, dilute, or wall off the infecting agent or injured tissue
5 cardinal signs of inflammation
Calor (heat)
Rubor (redness)
Tumour (swelling)
Dolor (pain)
Functio Laesa (loss of function)
Response type? specific or nonspecific
Non-specific e.g same for whatever has entered the body.
The first stage of the process
Bleeding phase
Second stage of the process
Inflammation phase
Third stage of process
Proliferative phase
Fourth stage
Remodeling stage
How long does the bleeding phase last
4-6 hours
How long does the inflammation phase last
peaks as 1-3 days and gradually resolves over a period of weeks
How long does the proliferative phase last
days to months
How long does the remodeling stage last
starts within weeks lasts up to a year
What happens in the bleeding stage?
Damage, trauma or injury to a body part results in bleeding at the site of injury
What does the bleeding duration in the bleeding stage depend on?
Depends on the structure that is bleeding e.g ligaments have a lower vascularity compared to muscles so would bleed less.
What happens in the inflammation stage?
Release of mast cells, platelets and macrophages into the surrounding tissue.
Inflammation phase: what happens once macrophages are present in the local tissue?
Proliferative mediators are released.
What are proliferative mediators?
chemicals which cause proliferation to occur. Proliferation is when the wound is rebuilt with new tissue.
Mast cells cause a release of chemical mediators e.g cytokines, which brings about 2 important responses…
- Vascular response
- Cellular response
Inflammatory phase- vascular response: what happens in this response?
Leads to vasodilation and increase in vasopermeability
What is vasopermeability?
Permeability of blood vessels increasing
Inflammation phase: Vasodilation and vasopermeability increases the flow volume through vessels. What does this lead to?
Leads to a leakage of exudate, which is the swelling within tissues.
What does exudate fluid do?
Dilutes irritants, helps formation of inital clots, traps any harmful debris from spreading
What causes swelling in the cardinal signs in inflammation?
Leakage of exudate fluid
What causes the redness and increase in temperature in the cardinal signs of inflammation?
Increase in blood flow because there is more blood closer to the surface.
Inflammation phase: what follows the release of chemical mediators in the cellular response?
Attraction of phagocytes
Inflammation phase- cellular response: Increased phagocyte activity causes the release of?
Lactic acid. Which helps trigger the proliferative phase of repair.
What are the 3 possible outcomes of the inflammatory phase? And what are they?
- Resolution- tissue irritation rather than damage
- Repair/healing- this requires a critical number of cells that have been damaged for this process to occur. It involves fibrin removal and gradual replacement by granulation tissue.
- Chronic inflammation- This can happen following an acute reaction OR develop with no initial reaction.
What happens in the proliferative phase?
Rapid cell growth
Wound is rebuilt with new tissue
Proliferative phase: why do some of the initial cytokine release need to be de-activated?
To allow the stimulation of the proliferative reaction. Once cytokinese have been deactivated, two processes start to occur.
Proliferative phase: what two processes start to occur once cytokine de-activation has taken place?
- Fibroplasia
- Angiogenesis
Proliferative phase: What is the fibroplasia process? What is it carried out by? What does it do?
The formation of fibrous tissue, carried out by fibroblasts. Process repairs connective tissue by laying down collagen fibres.
Proliferative phase: What is the Angiogenesis process? What is it carried out by? What does it do?
Formation of new blood vessels, carried out by endothelial cells. Process enhances local circulation through a process calls neovasculisation.
Proliferative phase- Fibroplasia: What does the activation of fibroblasts produce? And what are they responsible for?
Myofibroblasts. Which are responsible for contraction of the wound and providing early stage repair.
What do both the processes in the proliferative phase lead to?
Lead to an increase in proliferative activity by forming scar tissue by laying down granulation tissue.
What happens in the Remodeling phase?
Reorganization and refining collagen and extracellular matrix.
Remodelling phase: what causes the wound and fibres to become stronger?
The type of collage fibres changing
