The Cardiovascular System
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The cardiovascular system transports nutrients, gases, hormones, and cellular waste products throughout the body. Blood vessels are classified into 3 categories. Veins transport blood to the body and arteries transport blood from the heart throughout the body. Capillaries are tiny blood vessels one tenth the size of a human hair.
The heart is arguably the most important organ of the human body. Pumping over 10 million gallons of blood a year and beating 100,000 times a day, the heart begins to pump only after four weeks after fertilization of the human embryo. The fist-sized organ is divided into four major parts: the left & right atria, and the left & right ventricles.
Blood is comprised of 3 major parts. 10% of blood is liquid plasma. including nutrients and hormones. Platelets are responsible for blood coagulation. The other part, blood cells, is further divided into 2 categories: red blood cells carry O2 and CO2 throughout the body and contain the protein hemoglobin. White blood cells are a part of the lymphatic system and counter pathogens during infection.
Problems can arrise in the cardiovascular system when cholesterol (fat-like substance that is made by the body and is found naturally in animal), especially (LDL) Low-density lipoprotein, clogs up arteries and actuate heart disease. Heart disease is responsible for the most # of deaths in America. A heart attack occurs when the supply of blood to an area of heart muscle is blocked, usually by a clot in a coronary artery.
To prevent such diseases, eat a diet low in cholesterol. Abstain from smoking and engage actively in physical activity. The occasional stroll in the park or sports-game can help lower cholesterol levels and increase one's overall health.