HNN227 Final: ISCHAEMIA
1 Jun 2018
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Department
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HNN227
ISCHAEMIA
1
DEFINE THE TERMS ISCHAEMIA AND INFARCTION
Ischaemia is
an inadequate blood supply to an organ, muscle or tissue, causing a shortage of oxygen
and glucose needed for cellular metabolism to keep a tissue alive. If left untreated, it can result in
tissue death. It is caused by embolism (most frequent), thrombosis of a pre-existing atherosclerotic
artery, or trauma.
Infarction is
dying tissue or tissue death (necrosis) due to inadequate blood supply (ischaemia), usually
caused by thrombus or embolus. (Result of prolonged ischaemia)
IDENTIFY VARIOUS BODY SITES ISCHAEMIA MAY OCCUR AND POSSIBLE SUBSEQUENT
CONDITIONS
BODY SITES AND CONDITIONS:
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Brain – e.g. Stroke
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Eyes – e.g. Vision deficit
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Carotid artery
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Heart – e.g. Angina -> cardiac arrest and heart attack
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Small and large intestine – e.g. Bowel obstruction
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Kidneys – e.g. renal failure
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Digits (fingers and toes)
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Femoral arteries – e.g. PVD
SIGNS AND SYMPTOMS:
The six P’s:
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Pain
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Pallor
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Pulselessness
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Paraesthesia
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Paralysis
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Poikilothermia (adaption of the limb to the environmental temperature, most often cool)
find more resources at oneclass.com
find more resources at oneclass.com
DESCRIBE THE PATHOPHYSIOLOGICAL PROCESS OF ATHEROSCLEROSIS
It is a build up of cholesterol plaque (low density lipoprotein cholesterol) in the walls
(intimal and medial layer) of arteries, causing obstruction of blood flow.
- It is the major cause of coronary artery disease.
- Cholesterol can be good for you (HDL-C is good cholesterol), but too much can be
harmful (LDL-C is bad cholesterol). It is produced in the liver and found in certain
foods high in saturated fats.
- LDL-C can get into the smooth wall of the artery.
- First the body will try to defend the artery by activating macrophages to consume
LDL-C
- These become enlarged cells called foam cells imbedded in the vessel wall and can be
seen as fatty streaks
- As the fatty streaks grow they become plaque, this occludes the artery and causes the
obstruction of blood flow.
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Over time, calcium is deposited in the plaque making it hard and inflexible,
reducing artery elasticity, and inhibiting the blood flow when needed e.g. during
exercises
- This increases pressure and can cause the plaque to
rupture, causing acute occlusion
of the artery by clot.
- The consequences are possibly life threatening (stroke/heart attack).
RISK FACTORS:
- Smoking
- High blood pressure
- High cholesterol
- Diabetes
STATE THE COMMON SITES WITHIN THE ARTERIAL SYSTEM FOR ATHEROSCLEROTIC
PLAQUE DEVELOPMENT
ARTERIAL COMMON SITES FOR PLAQUE –
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Coronary arteries - left anterior descending artery
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Renal arteries
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Bifurcation (division into 2 branches) of carotid arteries
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Branching sections of peripheral arteries
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Ischaemia is an inadequate blood supply to an organ, muscle or tissue, causing a shortage of oxygen and glucose needed for cellular metabolism to keep a tissue alive. If left untreated, it can result in tissue death. It is caused by embolism (most frequent), thrombosis of a pre-existing atherosclerotic artery, or trauma. Infarction is dying tissue or tissue death (necrosis) due to inadequate blood supply (ischaemia), usually caused by thrombus or embolus. (result of prolonged ischaemia) Identify various body sites ischaemia may occur and possible subsequent. Heart e. g. angina -> cardiac arrest and heart attack. Small and large intestine e. g. bowel obstruction. Poikilothermia (adaption of the limb to the environmental temperature, most often cool) It is a build up of cholesterol plaque (low density lipoprotein cholesterol) in the walls (intimal and medial layer) of arteries, causing obstruction of blood flow. It is the major cause of coronary artery disease.
