The Cardiovascular System
The Cardiovascular System (also called circulatory system) circulates the blood around the body in order to supply all parts with required nutrients and oxygen and to remove waste products such as carbon dioxide.[1]
Blood and Blood Vessels
Blood consists of white blood cells, red blood cells, platelets and liquid plasma. Plasma accounts for about 50% of the total blood content and contains mainly water which has glucose, enzymes and other proteins, hormones and waste products dissolved in it. Oxygen and carbon dioxide are also present in the blood and are carried by the red blood cells.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title
Within the human body, blood is carried in blood vessels which can differ in size and makeup.
Arteries
innitiate from the heart and carry blood to organs and tissues where oyxgen and nutrients are need. Therefore, they carry blood which is rich in these components. The arteries pump blood by narrowing as the heart relaxes, so that the exerted force pushed the blood forward. Thick walls, muscular (see cardiac muscle), and elastic layers ensure that the strain due to the blood flow and the contraction of the heart does not damage the walls, which on average are only 1mm thick.
Veins
Capillaries
Heart Structure
Coronary Heart Disease
References
- ↑ Parker S. (2007) The Human Body Book, 1st edition, London: Dorling Kindersley Limited.