• Climate is patterns of weather conditions in a large area over a long period time.
• The sun sends out heat and light energy.
• Some travels through the atmosphere where it is absorbed by the lands and the oceans.
• The atmosphere is a layer of gases that surrounds the Earth. It protects Earth from the sun's harmful radiation and keeps the planet warm enough for life to exist.
• Gases in the atmosphere known as greenhouse gases trap some of the heat energy so that it is not too hot during the day and not too cold during the night.
• Greenhouse gases... (More)

• The heart is the pump of the circulatory system.
• It is made of cardiac muscle which does not tire.
• Cardiac muscle receives its own blood supply through the coronary arteries and veins.
• The septum divides the heart into right and left sides.
• The heart has four chambers; right atrium, right ventricle, left atrium, left ventricle.

Blood Flow Through the Heart

1. The blood flows into the vena cava into the right atrium. It is deoxygenated blood.
2. The valves open and allow the blood flow into the right ventricle. The valves close.
3. The right ventricle contracts, valves open and blood is pushed... (More)