week 2

• What is an embolus?

  A mass that can block a blood vessel
• What is the most common type of embolism?

  Pulmonary embolism from deep vein thrombosis
• What does the term thromboembolism refer to?

  Emboli from dislodged thrombus
• How does the outcome of an embolism depend on its origin?

  It depends on where they originate and lodge
• What are the sources of emboli?

  • Pieces of thrombus
  • Infected lesions
  • Gas bubbles (e.g., air, N2)
  • Fat and bone marrow
  • Tumour cells
  • Amniotic fluid
• What percentage of pulmonary emboli are small and clinically silent?

  60% to 80%
• What is the primary cause of pulmonary embolism cases?

  95% from leg deep vein thrombosis
• What can a pulmonary embolism cause?

  Sudden death and right heart failure
• What happens if the blockage is in a middle-sized vessel?

  It can cause pulmonary haemorrhage
• Where do systemic arterial emboli arise from?

  Arterial circulation
• What can multiple emboli over time lead to?

  Pulmonary hypertension
• What percentage of systemic arterial emboli come from intracardiac mural thrombi?

  ~80%
• What is the general outcome of arterial emboli?

  They cause tissue infarction
• What is an infarct?

  An area of ischemic necrosis
• What percentage of infarcts result from thrombotic or embolic events?

  Nearly 99%
• What causes tissue infarction?

  Occlusion of arterial supply or venous drainage
• What are other causes of infarction besides thrombotic events?

  Vasospasm and vessel compression
• What shapes can infarcts take based on occluded blood supply?

  • Wedge-shaped: in lung
  • Triangular: in kidney
  • Scarred: in spleen
• How are infarcts classified?

  • Based on color and infection presence:
  • White (anaemic): solid organs
  • Red (haemorrhagic)
  • Septic: infected infarct
  • Bland: uninfected infarct
• What factors influence the outcome of an infarction?

  • Nature of vascular supply
  • Availability of alternative blood supply
  • Rate of occlusion development
  • Vulnerability to hypoxia
  • Oxygen content of blood
• What is shock characterized by?

  Systemic hypotension due to reduced cardiac output
• What are the causes of shock?

  Cardiogenic, hypovolaemic, and septic shock
• What causes cardiogenic shock?

  Low cardiac output due to heart failure
• What causes hypovolaemic shock?

  Low cardiac output due to blood loss
• What causes septic shock?

  Vasodilatation and blood pooling from infection
• What is the final common pathway for several lethal clinical events?

  • Inadequate tissue perfusion
  • Characterized by systemic hypotension
• What is the Latin origin of the word inflammation?

  Inflamatio
• What is inflammation a biological reaction to?

  Noxious stimuli like microbes and trauma
• What is the fundamental purpose of inflammation?

  To protect the body from injury
• What are the two main types of inflammation?

  Acute and chronic inflammation
• Who first described acute inflammation and when?

  Celsus in the 1st century AD
• What are the four cardinal signs of acute inflammation?

  Rubor, tumor, calor, dolor
• What is the 5th sign of inflammation added by Virchow?

  Functio laesa (loss of function)
• What is the primary purpose of acute inflammation?

  To deliver leukocytes and plasma proteins
• What triggers acute inflammation?

  Infection, trauma, burns, allergic reactions
• How long does acute inflammation typically last?

  Hours to days
• What are the two main reactions involved in acute inflammation?

  Vascular and cellular reactions
• What are the three major components of acute inflammation?

  Vascular dilation, structural changes, leukocyte emigration
• What does vascular dilation in acute inflammation lead to?

  Increased blood flow
• What mediators induce vessel dilation?

  Histamine, bradykinin, NO