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Unit 19: Biology Part 2 Page 54 of 137
Coronary Circulation Figure 33 – The coronary
arteries branch off of the aorta
The heart is an organ, and like all and provide oxygen to the
organs, it needs oxygen. The heart.
process of providing the heart
muscle with oxygen is called Once the heart muscle receives the
coronary circulation. As we said oxygen it needs, the oxygen-poor
before, during systemic circulation, blood returns to the heart pump in
blood leaves the aorta and the cardiac vein.
branches out into many smaller
arteries. One set of arteries are Diseases of the Cardiovascular
called the coronary arteries. These System
arteries take blood to the heart
muscle and provide it with the The cardiovascular system is
oxygen it needs. This seems essential for life. If one or more
strange, because we have learned parts of the system are not
that arteries always go away from working properly, the result can be
the heart. To understand this, it’s serious illness or death. Three
helpful to think of the heart as two common diseases of the
different things – a pump that cardiovascular system are
sends blood everywhere it needs to hypertension, coronary heart
go and an organ that needs disease and stroke.
oxygen. Arteries always go away
from the pump, but they Hypertension
sometimes provide oxygen to the As we learned earlier, blood in
organ. arteries is under pressure, and this
pressure is referred to as blood
pressure. If you have ever had
your blood pressure taken, the
doctor or nurse probably used a
tool called a
sphygmomanometer, like one of
the ones shown below.
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