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Cardiovascular System Notes: Blood Vessels. Interesting Cardiovascular System Fact. The human body has 60,000 miles of blood vessels – long enough to go almost 3 times around the Earth!. NOTES – THE CARDIOVASCULAR SYSTEM (A.K.A. THE CIRCULATORY SYSTEM). 3 main parts. heart. blood.
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Cardiovascular System Notes: Blood Vessels
Interesting Cardiovascular System Fact The human body has 60,000 miles of blood vessels – long enough to go almost 3 times around the Earth!
NOTES – THE CARDIOVASCULAR SYSTEM (A.K.A. THE CIRCULATORY SYSTEM) • 3 main parts • heart • blood • blood vessels
Blood Vessels • ARTERIES • take blood away from the heart
3 layers 1. TUNICA EXTERNA: outside layer – made up of connective tissue
3 layers 2. TUNICA MEDIA: middle layer – made up of smooth muscle
3 layers 3. TUNICA INTIMA: inner layer – made up of endothelial cells (endothelium)
VEINS • bring blood to the heart • same 3 layers as arteries except the muscular layer is much smaller • also contain valves
Capillaries (photomicrograph of alveolar capillaries) • Function: the exchange of materials between the blood and the body’s cells • EX: oxygen, nutrients, waste • these are microscopic in size