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In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. [1] [2] It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and Latin vascula meaning vessels).
LVEF is an indicator of the effectiveness of pumping into the systemic circulation. The EF of the right heart, or right ventricular ejection fraction (RVEF), is a measure of the efficiency of pumping into the pulmonary circulation. A heart which cannot pump sufficient blood to meet the body's requirements (i.e., heart failure) will often, but ...
In the systemic circulation the return is of deoxygenated blood from the organs and tissues of the body, and in the pulmonary circulation the pulmonary veins return oxygenated blood from the lungs to the heart. Almost 70% of the blood in the body is in the veins, and almost 75% of this blood is in the small veins and venules. [7]
Therefore its circulation is of major importance not only to its own tissues but to the entire body and even the level of consciousness of the brain from moment to moment. Interruptions of coronary circulation quickly cause heart attacks ( myocardial infarctions ), in which the heart muscle is damaged by oxygen starvation .
Because blood vessels are not rigid tubes, classic hydrodynamics and fluids mechanics based on the use of classical viscometers are not capable of explaining haemodynamics. [ 2 ] The study of the blood flow is called hemodynamics, and the study of the properties of the blood flow is called hemorheology .
The short distance is important because the capillary diffusion rate decreases when the diffusion distance increases. Then, because of its large number (10-14 million capillaries), there is an incredible amount of surface area for exchange. However, this only has 5% of the total blood volume (250 ml 5000 ml).
Arterial compliance is an important cardiovascular risk factor. Compliance diminishes with age and menopause. Arterial compliance is measured by ultrasound as a pressure (carotid artery) and volume (outflow into aorta) relationship. [5] Compliance, in simple terms, is the degree to which a container experiences pressure or force without disruption.
However, because of allosteric effects on the hemoglobin molecule, the binding of CO 2 decreases the amount of oxygen that is bound for a given partial pressure of oxygen. The decreased binding to carbon dioxide in the blood due to increased oxygen levels is known as the Haldane effect , and is important in the transport of carbon dioxide from ...