Blood Vessels – Arteries, veins, and capillaries
Arteries
~Carry blood AWAY from the heart
~Largest is the AORTA
~Where PULSE is felt
~Thickest of blood vessels – contain smooth muscle which allow them to
expand and contract
~Usually carry oxygenated blood to body
Exception: pulmonary arteries carry deoxygenated blood to lungs
~Pulse is the wave of blood passing through the arteries for every beat your
heart makes. Average adult pulse is 72 beats per minute.
Blood pressure is measured in your arteries.
Typical blood pressure: 120 highest (pulse)
80 lowest (rest)
Low blood pressure:
100
60
High blood pressure 180
100
Veins
~Carry blood back to heart
~Thinner and darker than arteries
~Valves make sure blood flows forward
~Carry de-oxygenated blood
Exception: pulmonary veins carry oxygen back from lungs
~IV = intravenous (in the vein)
~Under less pressure than arteries
~Varicose veins – swollen with blood to the point where the valves are pulled
apart
Capillaries
~Connect arteries and veins
~Microscopic
~Enough capillaries to wrap around the earth twice
~Where food and oxygen/wastes and carbon dioxide are exchanged between
the blood and the cells
~Diffusion and osmosis occur in capillaries