The cardiovascular system includes the heart and blood vessels and is one of the most important systems in the body. By pumping blood throughout your body, the cardiovascular system delivers oxygen where it's needed and carries wastes away for disposal. In children, a properly functioning cardiovascular system ensures good health.
Function
Your child's cardiovascular system is her body's lifeline, and it encompasses her heart and circulatory system. This system delivers blood to your child's tissues throughout her body. Every heartbeat sends blood, oxygen and nutrients throughout her body. The circulatory system is composed of the heart and blood vessels, including arteries, veins and capillaries. Your child's body has two circulatory systems: his pulmonary circulation and systemic circulation. These systems work together to send blood from the heart to all the other parts of her body and back again.
Heart
The heart is the main organ in the cardiovascular system, and its main function is to pump blood throughout your child's body. Your child's heart will beat an average of 80 to 160 times per minute during his first year of life and will beat an average of 70 to 110 times per minute by the time he is 10. Your child's body tells his heart when to pump more or less blood depending on his needs. When he sleeps, his heart pumps less often due to a lower amount of oxygen needed by his body when he rests. When your child is active or scared, his heart pumps faster to get more oxygen throughout his body. Your child's heart has four chambers that are surrounded by thick, muscular walls. His heart is located between his lungs and on the left side of his chest cavity. The bottom part of his heart is divided into two chambers that pump blood out of his heart, referred to as his right and left ventricles, and the inter-ventricular septum divides these ventricles.
Function of Arteries
Arteries are blood vessels that carry blood away from the heart, and they contract to keep your child's blood moving away from her heart and through her body. Oxygenated blood is pumped from her heart into her aorta during the systemic circulation. Two coronary arteries branch off the aorta and divide into smaller arteries that provide oxygen and nourishment to the muscles of your child's heart. Her pulmonary artery carries poorly oxygenated blood from the right ventricle and divides into right and left branches. The blood then travels to her lungs, where her blood is oxygenated.
Veins and Capillaries
Veins are vessels that carry blood back to your child's heart, and they contain valves that prevent blood from flowing backward. Veins have three layers, just as the arteries do, but they are thinner and less flexible. The superior and inferior vena cava are your child's two largest veins and are located above and below his heart. Tiny capillaries connect his arteries and veins, and their function is to deliver nutrients to the cells, as well as remove waste products from his body.
Considerations
Waste and carbon dioxide are carried out of your child's body via her vascular system, but when this waste is not expelled properly, toxicity can occur within her body. Hormones are produced by your child's endocrine system, and these hormones are transported through her blood. Your child's hormones transfer information and instructions from one set of cells to another, so if her circulatory system is not functioning properly, the messages can be disrupted and all body systems are at risk of failure.
