The circulatory system carries venous blood from the right heart through the pulmonary artery to the lungs, in the pulmonary capillaries, carbon dioxide is expelled out and the blood receives oxygen to become arterial blood, following the pulmonary vein to the left heart, then the left heart. start a similar cycle through the great cycle
The cardiovascular system includes the heart and blood vessels, plays a very important role in the body, has a life nature. Undertake the following functions:
Provide oxygen and nutrients to the organization, and at the same time carry the substances that need to be eliminated to the organs responsible for excretion.
Fluid communication: transporting hormones, enzymes to organs, communicating between organs.
Regulate body temperature: the source of hot blood warms the organs and is responsible for removing heat from the body.
In the above functions, the task of providing oxygen and glucose for energy metabolism is the most important task.
Figure: Blood circulation in the body.
Brain cells lack energy even for a few seconds, have stopped working, if lack of energy for more than 5 minutes, it will be damaged hard to recover.
The heart acts as a pump, sucking and pushing blood into two circulations: microcirculation and minor circulation (Figure).
The great circulation (systemic circulation) carries arterial blood rich in oxygen and nutrients from the left heart to the aorta, which continues to divide into smaller arteries to the organs. In the organization, the arterioles connect with the capillary network, nutrients and gases will exchange through the thin walls of the capillaries, nutrients are supplied to the organization. The deoxygenated blood then enters the venules, is carried away from the tissue, to concentrate in the great veins, to the right heart.
The pulmonary circulation (pulmonary circulation) carries venous blood from the right heart through the pulmonary artery to the lungs, in the pulmonary capillaries, carbon dioxide is expelled out and the blood receives oxygen to become arterial blood, following the pulmonary vein to the lungs. left heart, then begins a similar cycle through the microcirculation.
Thus the heart is the main engine of circulation, the heart sucks and pushes blood into the arteries. Arteries and veins carry blood to the tissues and from the tissues to the heart. Capillaries are the site of metabolism between blood and tissues.