2 Acute Inflammation Flashcards
What happens in inflammation?
Fluid exudate and neutrophils accumulate in the tissues
What is acute inflammation? Is it:
i. ) Innate or learnt
ii. ) Immediate or delayed
iii. ) Variable or constant between events
iv. ) Long or short in duration
The response of living tissue to injury in order to limit tissue damage.
i. ) Innate
ii. ) Immediate
iii. ) Constant between events
iv. ) Short
Name 2 causes of inflammation
Infections Hypersensitivity reactions Physical agents Chemicals Tissue necrosis
What are the clinical signs of inflammation?
Rubor (redness) Tumor (swelling) Calor (heat) Dolor (pain) Loss of function
What changes does inflammation cause in the tissues?
Changes in blood flow
Exudation of fluid into tissues
Infiltration of inflammatory cells
Explain how acute inflammation causes changes in blood flow
Transient vasoconstriction of arterioles
Vasodilation of capillaries
Increases permeability of blood vessels
Increased viscosity of blood
How does acute inflammation causes exudation of fluid into tissues?
Arterial dilation => increased hydrostatic pressure => increased flow OUT of vessel
Increased permeability of vessel walls => increased colloid osmotic pressure of interstitium => increased flow OUT of vessel
What is oedema?
Excess fluid in the interstitium
What is ‘exudate’?
Fluid with a high protein content
What is ‘transudate’?
Fluid with a low protein content
What is the primary cell type involved in inflammation?
Neutrophil leukocyte
Polymorphonuclear leucocyte
Polymorph
(3 names- same cell type)
How do neutrophils infiltrate blood vessels?
Neutrophils line up along the endothelium (margination)
Roll along the endothelium (rolling)
Stick more avidly (adhesion)
Move through the blood vessel wall (emigration)
How do neutrophils exit blood vessels
Relaxation of the inter-endothelial cell junctions
What is chemotaxis?
Movement along concentration gradients of chemoattractants
What mechanism do neutrophils follow to remove waste?
Phagocytosis
Name the two killing mechanisms used by neutrophils
O2 dependent- produces superoxides and H2O2
O2 independent- lysozyme and hydrolases
Name 3 types of chemical mediators in acute inflammation
Proteases
Prostaglandins
Cytokines
How does exudation of fluid combat cell injury?
Increases lymphatic drainage
Dilutes toxins
Delivers plasma proteins to the site of injury
How does the infiltration of cells combat cell injury?
Removes pathogens
Removes necrotic debris
How does vasodilation combat cellular injury?
increases delivery and increases the temperature
How does pain and loss of function combat cellular injury?
Enforces rest
Reduces risk of further damage
Name 4 local complications of acute inflammation
Blockage of tubes
Compression of tubes
Loss of fluid
Pain and loss of function
In bacterial infections, what inflammatory cells will be present?
Neutrophils
In viral infections, what inflammatory cells will be present?
Lymphocytes
What is ‘shock’?
A clinical syndrome of circulatory failure. Blood pressure is lowered and heart rate increases.
What are the 4 possible outcomes of acute inflammation?
Complete resolution
Continued acute inflammation with chronic inflammation= abscess
Chronic inflammation and fibrous repair
Death
What is ‘resolution’?
The morphology of the area gradually reverses back to normal.
Exudate drains to the lymphatics, fibrin is degraded, neutrophils are phagocytosed
What are the symptoms of bacterial meningitis?
Acute inflammation in the meninges, vascular thrombosis, reduced cerebral perfusion, pus in the brain.
What are the symptoms of lobar pneumonia?
Fever, prostration, hypoxaemia, dry cough, breathlessness, inflammation of the lungs
What can cause a skin blister? How does it present?
Causes: heat, sunlight, chemicals
Presents as painful, clear exudate, leave a scar
What is an abscess?
Occurs in solid tissues when inflammatory exudate forces the tissue apart. Liquefactive necrosis occurs in the centre increasing the pressure. They can press on other structures and cause tissue damage
What happens when exudate pours into serous cavities?
Pleural or pericardial effusion resulting in respiratory or cardiac impairment
Name a disorder of the acute inflammation system
Hereditary angio-oedema
