The growth and development of the heart and blood vessels

Rheumatic fever is most likely to damage the cardiovascular system in children. That's why you need to know about the structure and operation of the heart.
Heart — A hollow organ, which consists mainly of muscle tissue. It is located in the left side of the chest cavity. Heart shape — pear. The base of the heart facing up, the top down and a few left.
Position of the heart in the chest of the child varies according to age.
A newborn baby and the first year of life heart is the lateral position. On the second and third year of life heart gradually acquires a twisted position. Changing the position of the heart is associated with a gradual transition of the child from the horizontal (lying down) position to a vertical.
Heart child, as an adult, has four chambers. The upper part of the heart forms the right and left atrium, the bottom — the ventricles. Muscular septum divides heart into two parts: the right includes the right atrium and right ventricle, the left — the same name the atrium and ventricle.
The wall of the heart consists of three layers, or shells. The inner shell, or endocardium lining the heart cavity and forms a valve regulating the flow of blood.
Average shell — is a muscle of the heart, reducing that promotes blood. Outer sheath — the pericardium — covers the heart muscle and forms the so-called heart bag.
In infants and young children are relatively large atrium, the right cavity more left. Later (usually 10-11 years) ventricles grow more strongly than the atria.
Newborn heart weight is 20 — 25 grams, and the volume of the cavities 20 — 22 cubic centimeters. For the whole period of childhood weight and volume of the cavities continually increasing, and this increase is amplified in the first 3 years of life and then in adolescence (12-16 years). At 16 heart weight reaches 240 grams, and the volume of 250 cubic centimeters, ie, increased 10 — 12 times.
Blood supply to the heart is coronary arteries. The arteries of the heart surround it like a crown and are therefore called coronary, and the distance that the blood through the arteries, capillaries and veins of the heart — coronary circulation.
The arteries of the heart, like all others, subject to the influence of the nerves.
Children coronary circulation is abundant and dense network of blood vessels, mainly small arteries, which ensures an adequate supply of blood to the heart and creates favorable conditions for the functioning of the cardiovascular system in children.
Vessels, arteries, veins, capillaries, the small child developed quite well. Capacity of blood vessels in children is two times more than the venous, in adults as they both have the same capacity vessels.
Growth and development of blood vessels in children mostly completed at 12 years of age.

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