CardiovascularSystem

==**Just like the other systems of the body, the cardiovascular system is essential to survival. Many parts of the system work together to circulate blood about the body. You will learn about parts of the system, such as the arteries, veins, and capillaries.**==


 * 2 main parts:**

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 * heart- PUMPS!
 * blood vessels- channel and deliver

They have 3 layers: Arteries are tough and thick-walled and are covered by elastic fibers. The main artery is called the dorsal aorta, which arises from the heart to pump blood. Arteries also absorb the pressure of a heartbeat and slow down blood.
 * Arteries:**
 * Outer- tissue
 * Middle- muscle
 * Inner- epithelial

Though veins are not as strong as arteries, they still play a primary function of receiving blood. They also have the same layers as arteries.
 * Veins:**
 * receive from capillaries after exchange of carbon dioxide and oxygen
 * transport waste-rich blood to lungs

These are the most fragile and thin.
 * Capillaries:**
 * connects arterioles and venules
 * where exchange of carbon dioxide and oxygen occur
 * involved in body's release of excess heat

Superior and Inferior Venae Cavae > Right Atrium > Right Ventricle > Pulmonary Trunk > Left and Right Pulmonary Artery > Lungs > Left and Right Pulmonary Vein > Left Atrium > Left Ventricle > Aorta > Body Cells > Venae Cavae
 * Circulation:**

People with a more optimistic attitude suffer less strokes and heart attacks and have a 55% less chance of suffering cardiovascular diseases. (BE HAPPY!)

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