Pathophysiology of inflammation Flashcards
what is physiology?
the science of the function of living things
what does pathophysiology mean?
the study of the disordered physiological process that causes/ results from or associated with a disease or injury
what does pathology mean?
the scientific study of the disease itself
what is disease?
A condition where the presence of an abnormailty is sufficient to cause a loss of normal health
what are some causes of inflammation?
Microbial infection Allergy Physical agents Chemicals Tissue necrosis
What are the 5 clinical features of acute inflammation?
Rubor - redness Calor - heat Tumor - swelling Dolor - pain Loss of function
what is suppuration?
When there is too much inflammation = this can lead to suppuration which is a process by which pus forms
what type of process is inflammation?
physiological process
what is cystitis?
inflammation of the bladder due to a urinary tract infection
what are inflammatory mediators?
messengers that act in cells and blood vessel to promote an inflammatory response.
what is the general mechanism of action of NSAIDs?
COX enzyme inhibitors
what are the sub-categories of inflammatory mediators?
- simple compounds (amines)
- peptides and proteins
- Eicosanoids (generated from fatty acid precursors)
examples of simple compound (amines) inflammatory mediators.
Histamine
Serotonin (5HT)
examples of eicosanoid inflammatory mediators.
Prostanoids
Leukotrienes
Lipoxins
Resolvins
examples of peptide and protein inflammatory mediators.
cytokinins
bradykinin
What is included in the cytokines sub-category?
interleukins
interferons (INF)
chemokines
colony stimulating factors
What is the role of interleukins?
Signal between white blood cells and other functions.
Pro-inflammatory and anti-inflammatory
What is the role of interferons (INF)?
Interfere with viral replication
What is is the role of chemokines?
control the migration of white blood cells
What is the role of colony stimulating factors?
stimulate the formation of maturing colonies of WBC
what is the TNF?
Tumour Necrosis Factor;
a signalling protein that binds to the transmembrane receptor and triggers activation of the inflammation pathway
what role does the complement cascade have?
Follow-up activation that maintains and amplifies process.
Opsonisation
what role do lysosomes have?
Digests intracellular components. Fuse with phagosomes to down material
What is the vascular response for inflammation?
Vasodilation (Increase blood flow)
An increase in vascular leakiness
What are the 4 main cascade types?
Kinin
Complement
Coagulation
Fibrinolytic
What is the role of the Kinin Cascade?
Opens vessels
Increases vascular permeability and mobilises pain
(Vasodilation)
What is the role of the coagulation cascade?
seals bleeding site
What is the role of the Fibrinolytic cascade?
Doesn’t allow too much clotting.
What does Nitric Oxide cause?
Vasodilation of the blood vessels. This aids the immune response.
What are antigen presenting cells?
A group of immune cells that mediate the cellular
response;
Dendritic cells
Macrophages
What role do antigen presenting cells have?
They process and present antigens for recognition
Explain the antigen presenting process.
Cells process a protein antigen. This is broken down into peptides, presented with class 11
What is a surveillance mechanism for inflammation?
pattern recognition receptors on sentinel cells
What do surveillance mechanisms respond to?
To pathogen - associated molecular patterns
What is fluid exudate?
Fluid filters from the circulatory system into areas of inflammation and lesions.
= clear like fluid or pus
What is cellular exudate?
A fluid rich in protein and cellular elements that oozes out of blood vessels due to inflammation and is deposited in nearby tissues.
What are 2 processes are antigen presenting cells involved in?
Innate and Adaptive immunity
What pathway is antigen presenting cells?
Endocytic pathway
What is the Lymphatic system?
Network of tissues and organs that help rid the body of toxins, waste and other unwanted materials
State the primary role of the lymphatic system.
Transports Lymph around the body
What does Lymph consist of?
White blood cells, (lymphocytes)
Chyle (fluid from the intestines containing proteins and fats)
What is the role of immature CD4 cells?
Produces helper cells
What is the role of helper cells?
Help the T-cells with its cytotoxic roles
How does inflammation start?
Trigger, Detection, Signalling
Pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patter (DAMPS) are recognised by sentinel cells
Damage can directly release histamine, prostaglandins and leukotrienes
examples of immune sentinel cells?
macrophage, monocytes and mast cells
What is the role of sentinel cells?
They patrol the body for signs of infection as the have pattern recognition receptors that release inflammatory mediators when bound
What happens after an inflammatory signal has been released?
PAMP and DAMP release cytokines, histamines and prostaglandins.
These mediators cause vasodilation (Rubor, calor)
and increases vascular leakiness (Tumor)
What does fluid exudate comprise of?
Clotting factors Coagulation cascade Fibrinolytic cascade Kinin cascade Complement cascade - releases histamine and opsonisation
What is antibody opsonization?
Pathogen is marked/ tagged for destruction by opsonins that allow recognition by the immune system of the body
What is cellular exudate?
- Chemokines attract circulating cells
- Adhesion molecules e.g. E-selectin increases adherence to endothelial cells, allowing migration into tissues
- Neutrophils predominate
Explain antigen presentation
Antigen is processed by cell and presented with major histocompatibility complex.
These proteins are found on cell surfaces and help the immune system recognise foriegn substances.
