CHAPTER 27: INTRODUCTION TO CARDIOVASCULAR PATHOLOGIES
There are a number of terms that are commonly used to describe the pathogenesis and clinical signs and symptoms of cardiovascular pathologies. These terms must be clearly defined to achieve a full understanding of cardiovascular conditions.
Definitions:
Ischemia
The term ischemia is used to describe the reduced flow of ________________ to an organ or tissue. Ischemia can be caused by the blockage of a blood vessel, insufficient blood volume or constriction of a blood vessel.
Hypoxia
The term hypoxia is used to describe the insufficient delivery of ________________ to the body or to a tissue or organ. Hypoxia can be caused by ischemia, reduced oxygen content, low atmospheric pressure, anemia or erythrocytopenia.
Thrombus
Thrombus is commonly referred to as a “________________ ”. This describes an aggregation of platelets and fibrin as well as other solid blood constituents that forms in an _____________ blood vessel. The thrombus partially or fully obstructs the lumen of the blood vessel causing ischemia and hypoxia of the tissues supplied by the affected vessel. Thrombi can be caused by insufficient fluid in the blood, ____________________of the blood or the over production of platelets or fibrin.
Embolus
An embolus is a mass inside a blood vessel. An embolus can be composed of a solid, a liquid or a gas, and can ________________ through the larger blood vessels. Emboli become stuck in the smaller vessels causing obstruction or rupture of the vessel. This causes ischemia, hypoxia and necrosis of the tissue supplied by the affected vessel.
Infarct
An infarct describes an area of _____________________ following ischemia and hypoxia. Generally, infarct is used to describe the necrosis of heart tissue during a heart attack but is also used to describe the ischemic necrosis of other organs such as the kidneys and liver.
Occlusion
Occlusion is the term used to describe the ______________________ of the lumen of a blood vessel. Occlusion can occur through vascular constriction, thrombus or embolus formation, or through external pressure on the vessel wall.
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