Hypoxia, Ischaemia and Infarction

Question 1

What is ischaemia?

Answer 1

• Result of impaired vascular perfusion- not nutrients to tissue
• Deprives affected tissue of vital nutrients
• Effects on tissue dependent on duration, if it lasts longer might lead to infarction

Question 2

What is infarction?

Answer 2

• Death (necrosis) of tissue as a result of ischaemia

- Irreversible

Question 3

What is cell death?

Answer 3

• Necrosis or apoptosis
• Necrosis is always pathological
• Irreversible

Question 4

What is shock?

Answer 4

State of circulatory collapse–>impaired tissue perfusion

Question 5

Describe what happens during an infarction

Answer 5

• Ischaemic cell death of tissue

- Infarcts elicit an inflammatory reaction because infarction is always pathological

Question 6

What is gangrene?

Answer 6

• Infarction of mixed tissues in bulk (e.g. gut wall, part of a limb)

Question 7

What is hypoxia?

Answer 7

• Reduction of oxygen, it can still lead to ischaemia

Question 8

What causes vascular occlusion?

Answer 8

• In lumen
• In wall
• Outside wall
• Underlying process is usually atherosclerotic disease

Question 9

What are the luminal causes of arterial occlusion?

Answer 9

• Thrombosis
• Embolism
• Thromboembolism
• • Embolus forms and detaches from plaque and travels through body and wedge itself in smaller blood vessel
• Anything distal undergoes infarction

Question 10

What are the mural causes of arterial occlusion?

Answer 10

• Wall of blood vessel
• Atheroma/Vasculitis
• Atheroma may cause partial obstruction
• Vasculitides- involves condition of inflammation of blood vessel wall

Question 11

What are the extraluminal causes of arterial occlusion?

Answer 11

• Something outside wall that can push vessel and cause occlusion
• Unusual, occasionally neoplasms