The human cardiovascular system is made up of the heart, arteries, veins and capillaries. The heart has two sides, the left and the right side. Oxygen rich blood travels from the left side of your heart out the aorta to various parts in the human body. Once the oxygen is depleted from the blood, it travels to the right side of the heart, which pushes it via the pulmonary artery to the lungs where the blood becomes oxygenated again and then returns to the left side of the heart where the process begins anew. Arteries carry oxygenated blood away from the heart and to different parts of the body. Veins are similar to arteries, but they are smaller and weaker. Once oxygen has been removed from the blood, veins carry the blood back to the heart. Capillaries are weaker than veins and deliver oxygen to the body's cells and carry the blood that has been depleted of oxygen and has had carbon dioxide added, back to the veins.
There are approximately 5 liters (5.3 quarts) of blood circulating through the adult human body. In an average 3-year-old child, there are approximately 2 pints of blood. The blood travels via arteries, veins and capillaries. The capillaries are so narrow that blood cells must travel through them in single file.
Length of It All
If all the veins, arteries and capillaries were strung together, they could circle the globe two and half times. There are more than 60,000 miles of blood vessels in an adult body.
The sound of a heartbeat is really the sound of the heart valves closing as blood is pushed through the heart chambers. An average heart beats about 30 million times in a year. An average adult heart pumps about 4,000 gallons of blood a day. A heart at rest contracts and relaxes about 70 times per minute.
Chocolate can actually improve cardiovascular health. According to the Northwest Health Sciences University, chocolate contains cocoa which has antioxidants that help protect the cardiovascular system. The antioxidants help lower blood pressure and help reduce deaths related to cardiovascular disease. A 4-5 gram (less than an ounce) serving per day is enough to gain the benefits from the antioxidants found in cocoa.
Optimism Helps Hearts
Having an optimistic attitude about life and life's circumstances can lead to a healthier cardiovascular system according to the Northwest Health Sciences University. People who have an optimistic attitude as opposed to a pessimistic attitude suffer fewer strokes and heart attacks and have a 55 percent less chance of suffering cardiovascular diseases.