to the body again in a never ending circle.
So in summary then what we have talked about
so far in this introductory talk is the definition
of the cardiovascular system. It is the blood
circulating organ system, that transports
nutrients, gases, hormones, and blood cells
throughout the body. It has a number of components
including the pumping part, the heart. It has
blood vessels and lymphatic vessels. Lymphatics
are used for draining any excess fluid that
escapes from the capillaries and finally we
have talked very briefly about the physiology.
The highest pressure is right above the aortic
valve when the left ventricle squeezes and
then the pressure falls progressively, particularly
falling at the resistance vessels the arterioles.
Eventually there is low pressure as the blood
passes through the very thin walled capillaries
giving off its oxygen and taking on waste
products such as carbon dioxide and eventually
working into small veins and larger veins
and returning to the heart to repeat the cycle