The Cardiovascular System: The Circulatory System

The cardiovascular system, also known as the circulatory system, is composed of the heart, blood vessels, and blood. The term cardiovascular refers to the heart (cardio-) and blood vessels (vascular). The term circulatory refers to the circulation of the blood. The heart is a muscular pump and its regular contractions send blood into tough, elastic tubes called arteries, which branch into smaller vessels and convey oxygen-rich blood through the body. The arteries eventually divide into tiny capillaries, which have such thin walls, that oxygen, nutrients, minerals, and other substances pass through to surrounding cells and tissues. Waste substances flow from the tissues and cells into the blood for disposal. The capillaries join and enlarge to create tubes that eventually become veins, which take blood back to the heart. Vessels carrying oxygenated blood (usually arteries) are shown in red and those carrying deoxygenated blood (usually veins) are blue.
The cardiac muscle of the heart wall depends on a constant flow of blood supply by the coronary arteries. Coronary arteries are blood vessels that arise from the base of the aorta and bring freshly oxygenated blood to the heart muscle. If this supply is restricted, then oxygen and nutrients can’t reach the muscles and the result could be a form of coronary artery disease (CAD). It can also be known as coronary heart diseases (CHD). This form of partial or complete block can be caused by fatty deposits, blood clots, or both. Overall, the extent of the symptoms of coronary artery disease depends on the location, severity, and how fast the disease will start from the limited blood supply.