Study helps explain why exercise guards against heart disease

Regular exercise protects the cardiovascular system by reducing risk factors such as cholesterol and blood pressure. "But we believe there are certain risk factors for cardiovascular disease that are not fully understood," ...

Medical research

Glowing cholesterol helps scientists fight heart disease

A newly developed technique that shows artery clogging fat-and-protein complexes in live fish gave investigators from Carnegie, Johns Hopkins University, and the Mayo Clinic a glimpse of how to study heart disease in action. ...

Diseases, Conditions, Syndromes

Connective tissue disease increases risk for cardiovascular problems

A study based on medical records from more than a quarter million adult patients found that African-American patients with connective tissue diseases such as lupus or rheumatoid arthritis were twice as likely as white patients ...

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Circulatory system

The circulatory system is an organ system that passes nutrients (such as amino acids and electrolytes), gases, hormones, blood cells, nitrogen waste products, etc. to and from cells in the body to help fight diseases and help stabilize body temperature and pH to maintain homeostasis. This system may be seen strictly as a blood distribution network, but some consider the circulatory system as composed of the cardiovascular system, which distributes blood, and the lymphatic system, which distributes lymph. While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. The most primitive animal phyla lack circulatory system. The lymphatic system, on the other hand, is an open system.

The main components of the human circulatory system are the heart, the blood, and the blood vessels. The circulatory system includes: the pulmonary circulation, a "loop" through the lungs where blood is oxygenated; and the systemic circulation, a "loop" through the rest of the body to provide oxygenated blood. An average adult contains five to six quarts (roughly 4.7 to 5.7 liters) of blood, which consists of plasma, red blood cells, white blood cells, and platelets. Also, the digestive system works with the circulatory system to provide the nutrients the system needs to keep the heart pumping.

Two types of fluids move through the circulatory system: blood and lymph. The blood, heart, and blood vessels form the cardiovascular system. The lymph, lymph nodes, and lymph vessels form the lymphatic system. The cardiovascular system and the lymphatic system collectively make up the circulatory system.

This text uses material from Wikipedia, licensed under CC BY-SA