CSIM 1.48-49 Inflam & Repair 1 & 2 Flashcards
Describe acute inflammation
24-48 hours
Causes varied - cellular injury, microbial infection, physical damage, necrosis, hypersensitivity
Rubor, calor, tumor, dolor
Redness, heat, swelling, pain.
Clinical features- fever, swelling, pain, heat, raised ESR/CRP/WBC
Describe the mechanism of inflammation on a cellular level
Vascular dilation - increased blood flow
Increased vascular permeability - swelling
Leukocyte migration - neutrophilic infiltration “chemotaxis”
Increased lymphatic flow - clear fluids, dilute toxins and carry antigens to lymph nodes
Explain chemotaxis
Neutrophils regularly circulate in the blood. When inflammation occurs, chemotaxins are found in the area of inflammation, this causes “margination” of neutrophils to the endothelium of the vessel. The neutrophils then procede to adhere themselves to the endothelium and begin the process of migration where the cells squeeze through the endothelial cells to gain entry to the site.
This process is mediated by selectin and other chemotaxins.
List 4 possible sequelae in inflammation
Resolution
Repair
Suppuration
Chronic inflammation
What is suppuration? Possible sequelae of suppuration
Formation of pus.
Pus is a yellow viscous fluid that is filled with cellular debris from the immune response against the infection. It consist of DNA, protein, neutrophils.
Reabsorption, abscess formation or empyema.
Describe the basic process of wound healing/reparation
Repair is done by replacing specialised tissue with fibrous tissue. The processes is called granulation tissue formation.
These cells work together to remove debris, angiogenesis, produce extracellular matrix to patch up the damage which then turns into fibrous tissue. Wound repair also involves contraction which pulled the two sides together to close the wound (myofibroblast)
4 cells involved in wound repair
Endothelial cells, myofibroblast, fibroblasts and macrophages
What mediates repair?
Growth factors e.g. Endothelium-growth factor, vascular endotheliual growth factor.
Complications of wound repair
Stricture/narrowing
Keloid
Impaired mobility
What can affect the repair of a wound?
Infection Ischaemia Movement Nutrition/age Steroid De-nervation
List some pro-inflammatory cytokines
IL-1 IL-6 IL-12 IL-17 IL-18 TNF-alpha IFN-gamma
List some anti-inflammatory cytokines
IL-4 IL-10 IL-11 IL-13 TGF-beta IFN-alpha
Which cytokine causes pyrexia?
Il-1
Describe some systemic effects of inflammation
Fever caused by release if IL-1
Raised CRP by the liver
Redirected blood due to autonomic response
Behavioural changes like malaise, rigors and anorexia
What are some macroscopic signs of inflammation?
Swelling, suppuration, catarrhal, fibrinous occurances like percarditis.
Why is swelling of the brain harmful?
Confined area, raised ICP, compresses brain parts, can cause brain herniation.
Describe what a granuloma is
Aggregate of histiocytes +/- lymphocytes
Secretion>phagocytosis
Epitheloid appearance
Can result in fusion of cells, creating giant multi-nucleated cells
Marker of chronic inflammatory disorders
Describe
= foreign body granuloma giant cell
= touton giant cell
= langerhans giant cell
= foreign body trapped in the body, hundred of nuclei
= fill with cholesterol/fat, ring of nuclei, e.g. Exthalasma
= TB associated, horse shoe nuclei
Describe the some causes of chronic inflammation
Persistent infection
Poorly degradable material e.g. Asbestos
Autoimmune disease
Describe some causes of persistent infection
Chronic abscess
Indigestible material like a splinter
Resistant organisms like TB or parasites
Macroscopic signs of chronic inflammation
Chronic abscess Fistula Sinus Chronic ulcer Fibrosis and strictures Granulamatous inflammation
What is a fistula?
Connecting of two epithelial areaz through a conduit e.g. Intestine fistual
Some microscopic signs of chronic inflammation
Tissue destruction
Repair (fibrosis/granulation)
Inflammatory cells like lymphocytes, neutrophils, macrophages, plasma cells
Granuloma
What is amyloidosis?
Accumulation of starch like extracellular material made of beta pleated sheets of protein called Amyloid
Becomes hard/waxy, resistant to removal
Occurs around blood vessels and skin blisters
Can cause problems in kidney and if in brain -> alzheimer’s
Some complications of chronic inflammation
Amyloidosis
Carcinogenesis
Calcification
Hypersensitivty reactions III and IV
Describe the role of neutrophils in inflammation
WBC, phagocytosis of pathogen
AKA polymorphs
Hallmark of inflammation, showed up 6-24 hours after
Work by binding opsonised pathogens then phagocytose and lyse them.
