Acute Inflammation Flashcards
What are the clinical signs of acute inflammation?
Rubor Tumor Dolor Calor And loss of function
What are the causes of acute inflammation?
Microbial infections Hypersensitivity reactions Physical agents Chemicals Tissue necrosis
What happens to blood flow in acute inflammation?
Transient vasoconstriction (to prevent blood loss)
Vasodilation of arterioles then capillaries (increased flow)
Increased permeability of vessel wall (exudation of fluid, slows flow)
Stasis (increased viscosity of blood)
Which cells release histamine?
Mast cells
Basophils
Platelets
What are the effects of histamine?
Vascular dilatation
Transient increase in vascular permeability
Pain
What are the mechanisms of vascular leakage?
Endothelial contraction Cytoskeletal reorganisation Direct injury Leukocyte dependent injury (ROS and enzymes) Increased transcytosis
What are the steps of neutrophil infiltration?
Margination
Rolling
Adhesion
Emigration
Define diapedesis
Change in cell shape to move through a vessel wall
What are the 3 steps of phagocytosis?
Contact
Recognition
Internalisation
Which opsonins facilitate phagocytosis?
Fc and C3b
What is the oxygen dependent killing mechanism?
Oxidative burst of superoxide and hydrogen peroxide
What is the oxygen independent killing mechanism?
Lysozyme and hydrolases released
Which mediators increase blood flow?
Histamine
Prostaglandins
Which mediators control vascular permeability?
Histamine
Leukotrienes
Which mediators initiate neutrophil chemotaxis?
C5a
LTB4
Bacterial peptides
Which mediator is most responsible for control of phagocytosis?
C3b
Why does exudation of fluid occur?
Deliver plasma proteins to area of injury
Dilute toxins
Increase lymphatic drainage
What are the local complications of acute inflammation?
Swelling (blockage of tubes)
Exudate (compression)
Loss of fluid
Pain and loss of function
What are the systemic complications of acute inflammation?
Fever (due to endogenous pyrogens and prostaglandins)
Leukocytosis
Acute phase response
Acute phase proteins
Describe acute phase response
Decreased appetite
Raised pulse rate
Altered sleep patterns
Name the acute phase proteins?
C reactive protein Alpha 1 anti trypsin Haptoglobin Fibrinogen Serum amyloid A protein
What are the possible end points of acute inflammation?
Complete resolution
Continued acute with chronic
Chronic inflammation and fibrous repair
Death
Name some signs of lobar pneumonia
Fever Prostration Hypoxaemia Dry cough Breathlessness
Describe an abscess
Occur in solid tissues where the inflammatory exudate forces the tissue apart. Under high pressure causing pain and has liquefactive necrosis in the centre.
90% of lobar pneumonia is due to which bacteria?
Streptococcus pneumoniae (pneumococcus)
Which ages group does lobar pneumonia typically affect?
20-50 years
What are the 4 stages of lobar pneumonia?
Congestion
Red hepatisation
Grey hepatisation
Resolution
In acute appendicitis, what is the inflammation often precipitated by?
Obstruction due to:
Faecolith
Lymphoid hyperplasia
Tumour
What is hydrocephalus?
Abnormal accumulation of cerebrospinal fluid in the brain causing increased intracranial pressure
Cholangitis is inflammation of the …
Bile ducts
What is cholangitis associated with?
Inflammatory bowel diseases (especially ulcerative colitis)
What are the common signs of cholangitis?
Abdominal pain
Jaundice
Fever
