Haemorrhage and oedema Flashcards
What is haemorrhage?
Escape of blood from vascular system
What is the difference between haemorrhage and hyperaemia?
Haemorrhage = extravascular Hyperaemia = intravascular
What causes haemorrhage?
Physiological cause Trauma Infectious agents and their toxins Clotting deficiencies Tumours Agonal respiration (gasping, laboured breathing)
What can haemorrhage lead to?
Anaemia (iron deficient)
Hypovolaemic shock
Loss of function
Complete recovery
Describe the degradation of haemoglobin by macrophages and the colours
Haem - red
Biliverdin - green
Bilirubin - blue/green
Haemosiderin - gold
What is diapedesis? (A type of haemorrhage)
Movement of RBCs into extravascular space due to endothelial defects
What is rhexis?
Break in a vessel wall
What is a haematoma?
Clotted accumulation of blood within an organ/cavity
Haemorrhage can be named according to its size. What are the 3 names?
Petechia
Purpura
Ecchymosis
What size is petechia? Where is it found? What is it associated with?
1-2mm
Skin, mucus and serous surfaces
Associated with increased vascular pressure, thrombocytopenia and clotting factor deficits
What size is prupura? What is it associated with?
> 3mm
Similar to petechia - thrombocytopenia ,clotting factor deficits, increased vascular pressure
What size is ecchymosis? Where is it located? What causes it?
1-2cm
Subcutaneous
After trauma
Give examples of names for blood accumulating in cavities
Haemothorax
Haemoperitoneum
Haemopericardium
Haemoarthrosis (joint cavity)
What is oedema?
Accumulation of fluid in intercellular space or body cavities
Oedema can be localised or generalised. Species have different predilection sites. What are these in the dog, cat, sheep, horse and ox?
Dog - peritoneum (hydroperitoneum) Cat - thorax (hydrothorax) Sheep - submandibular and peritoneum Horse - limbs Cattle - brisket (lower chest)
What is a transudate? What is an exudate?
Exudate - fluid leaks around cells of capillary, caused by inflammation
Transudate - fluid pushed through capillary due to high HSP
What processes can cause oedema?
Increased hydrostatic pressure Decreased oncotic pressure (hypoproteinaemia) Lymphatic obstruction Sodium retention Inflammation
What is ascites? What is anasarca?
Ascites = hydroperitoneum Anasarca = subcutaneous oedema
What diseases cause oedema?
Heart failure
Chronic liver disease (decreased protein synthesis)
Renal disease (protein loss)
Pulmonary oedema is caused by what type of heart failure?
Left sided backwards (congestive)
Causes passive hyperaemia and oedema
Why is oedema of the brain serious?
No room to swell
CNS has no lymphatics so struggles to drain
What is glaucoma?
Oedema of the eye
What is bottle jaw? What causes it?
Subcutaneous, submandibular in ruminants
Hypoproteinaemia (decried oncotic pressure) in Johne’s disease and hepatic parasites
How does heart failure cause oedema?
Increased capillary hydrostatic pressure
Decreased renal blood flow activates RAAS and increases water retention and blood volume
