Circulatory

=**Circulatory System** =
 * moves substances to and from cells, where they are needed to produced, responding to changing demands.
 * the heart is the central organ that pumps the blood through the body
 * consists of heart, blood, and blood vessels.


 * What is the function of the heart?**
 * The heart works as a pump that pushes blood to the organs, tissues and cells of the body.


 * Heart Vocabulary-**
 * **Pulmonary Artery-** takes blood to the lungs to receive oxygen
 * **Vena Cavas-** brings blood from head and body back to the heart
 * **Right Artium-** receives de-oxygenated blood from the body
 * **Right Ventricle-** pumps blood up the pulmonary artery to the lungs.
 * **Aorta**- carries the blood to the head and the body
 * **Pulmonary Veins**- takes blood from the lungs back to the heart
 * **Left Atrium**-receives blood from the lungs, freshly oxygenated
 * **Left Ventricle-** pumps blood up the aorta to the body


 * Pathway of Blood Through the Heart-**
 * 1) Blood enters the heart from the body (de-oxygenated)
 * 2) Through the Vena Cavas
 * 3) Into the Right Atrium
 * 4) To the Right Ventricle
 * 5) Through the Pulmonary Artery
 * 6) To the lungs (picks up oxygen and drops of CO2)
 * 7) Back in the Pulmonary Veins (from the lungs)
 * 8) Into the Left Atrium
 * 9) To the Left Ventricle
 * 10) Through the Aorta (to the body, drops of oxygen to body cells and picks up CO2


 * Other Important Vocabulary**-
 * **Arteries-** blood vessels that carry blood away from the heart
 * **Veins-** blood vessels that carry blood back to the heart and contain valves to keep blood flowing in one direction
 * **Capillaries-** are small blood vessels that can be only seen with a microscope and carry blood to each body cell
 * **Plasma-** liquid part of blood that cells float in and is mostly water with dissolved substances
 * **Red Blood Cells-** transport oxygen
 * **White Blood Cells-** are part of the immune system and fight diseases
 * **Platelets-** form blood clots so a cut can stop bleeding