Describe how blood is pumped and circulated through the body. include the roles of the four chambers of the heart, the major blood vessels leading in and out of the heart and lungs, and the arteries, capillaries, and veins found in the body.

Blood is pumped out of our body but pressure; which is what we call a "blood pressure".

Blood will enter our heart from after being circulated through the body to re-oxygenate through the superior and inferior vena cava and dumps the floor into the right atrium. Blood passes through the tricuspid valve and enters the right ventricle. From the right ventricle it passes into the pulmonary valve.

From the pulmonary valve is goes through the pulmonary artery (which is the only artery to carry deoxygenated blood) and goes into the lungs for diffusion (oxygen/carbon dioxide exchange) to re-oxygenate the blood and get rid of the carbon dioxide from the blood and out through the lungs.

After the blood passed through the capillaries via the lungs; it goes through the pulmonary vein (the only vein to carry oxygenated blood) and returns back into the heart at the left atrium.

Blood will pass from the left atrium through the bicuspid valve (mitral valve) and into the left ventricle. After the left ventricle, the blood is ready to circulate into the body and will pump out through the aorta.

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.