2. Circulatory System - the system of blood, vessels, and heart concerned with circulation of body fluids. Plasma - the watery part of blood cell that carries nutrients wastes, and blood cells. Red Blood Cell - the kind of blood cell that carries oxygen to other body cells. White Blood Cells - the kind of blood cell that fights germs. Platelet - a tiny part of a cell that helps stop bleeding. Artery - the kind of blood vessel that carries blood away from the heart. Capillary - a tiny blood vessel with thin walls through which oxygen, nutrients, and wastes past Vein- the kind of blood vessel that carries blood back to the heart. veins. Ventricle - one of two spaces in the bottom part of the heart that pump blood out of the heart. Atrium - one of two spaces in the top part of the heart that receive blood from

3.  The circulatory system is made of a network of flexible tubes that carry blood to all parts of the body. The major parts of the circulatory system includes the heart, lungs, arteries, and veins. Have you ever heard the sound of a heart beating? Click here to hear what your heart sounds like to your doctor. With each beat, the heart pumps blood that delivers life-sustaining oxygen and nutrients to your body's 300 trillion cells. Visit Amazing Heart Facts to learn more nifty facts about the heart and circulatory system.

4.  One of the most interesting facts of circulatory system is how it functions. The heart pumps blood, which is sent to the four chambers of the heart. The heart has two ventricles and two atria. The left ventricle pumps oxygenated blood to the other organs of the body; on the other hand, the right ventricle pumps the blood to the lungs. The heart has four valves which control the flow of the blood. The right atrium contains blood that is low in oxygen. When the valve opens, this blood is pumped into the right ventricle, similarly another valve opens to pour the blood into the pulmonary artery which carries the blood to the lungs for oxygen. The left atrium brings oxygenated blood into the left ventricle via another valve and into the aorta, which then sends the blood to the other body parts. Take a look at some other circulatory system facts by reading how does the circulatory system work.

5.  The left side of the heart contains oxygenated blood whereas the right side has de- oxygenated blood.  One drop of blood has about 5 million red blood cells and 12 thousand white blood cells.  The heartbeats about 30 million times in 365 days.  10 million blood cells die in the human body every second, the same quantity is produced at the same time.  Blood circulates the entire body in 20 seconds.  An average heart pumps about 450 gallons of blood everyday.  One of the surprising circulatory system facts is that the heartbeat is the sound of the valves opening and closing.  An average adult's body has about 5 liters of blood in it and a baby's body has about 1 liter of blood in it.  A human heart is a muscle which is the size of a clenched fist.  Blood cells die in every 4 months.  The plasma in the blood is made in the liver.  One of the amazing facts of circulatory system is that the heart continues to beat even when it is taken out of the body!  Read on:

6.  plasma red/white blood c cells arteries

7.  capillaries veins  ve atruim atrium atruims atrium ventricle