Perfusion
Perfusion is the essential process of delivering fluids, particularly oxygenated blood, from the circulatory system to tissues and organs. This process is critical for maintaining health in both humans and animals, as it facilitates the supply of oxygen and nutrients necessary for various bodily functions. Effective perfusion occurs during the heart's systolic phase when blood is pushed through arteries to the tissues, while the heart itself is perfused during diastole when blood fills its chambers. Poor perfusion can lead to ischemia, where blood supply is inadequate, potentially resulting in serious health issues such as cardiovascular disease.
Historically, the understanding of perfusion has evolved, particularly through the work of Danish physiologist August Krogh, who explored how blood flow is regulated in smaller vessels called capillaries. In surgical settings, perfusion can be artificially managed by trained professionals known as perfusionists, who use specialized machines like the heart-lung machine to maintain blood circulation during operations. Various types of artificial perfusion techniques exist, including extracorporeal circulation and extracorporeal membrane oxygenation, which support patients whose natural perfusion is compromised. Overall, the concept of perfusion is vital in both physiological contexts and medical interventions.
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Perfusion
Perfusion is the process of fluid passage from the circulatory or lymphatic system to tissues or organs. Perfusion is often referenced when discussing blood flow and the effectiveness of blood passage through the circulatory system to blood vessels in tissue. Good perfusion is important to overall health in humans and animals. Getting sufficient blood supply to tissues and organs is paramount to achieving many bodily processes that promote overall health. When perfusion is poor, it can cause a condition known as ischemia, which is when blood supply has difficulty reaching a tissue or organ. Poor perfusion can lead to a number of health problems such as cardiovascular disease among other conditions. During some types of major surgery, perfusion must be conducted mechanically by professionals known as perfusionists.
Overview
The study and understanding of perfusion dates back to the early twentieth century when Danish physiologist August Krogh won the Nobel Prize "for his discovery of the capillary motor regulating mechanism." Krogh developed ways to more precisely measure blood oxygen levels and described how the oxygen supply to muscles was regulated by the body. Previous knowledge held that the body's rate of blood flow increased during exertion, but Krogh showed that oxygen flow was regulated as smaller blood vessels opened called capillaries. This showed that blood passage to muscles and organs were adaptable as these tiny blood vessels opened and closed.
The word perfusion derives from the French "perfuse," which means to "pour over or through." In the human body, perfusion is the delivery of oxygenated blood to the tissues and organs. Perfusion occurs during the ordinary circulatory cycle, specifically in tandem with the heart's beating. When the heart beats, it beats in two cycles. The first cycle is referred to as systole, which is when the heart's chamber contract and force blood through the arteries. The second cycle is called diastole, which is when the heart's chambers relax and fill up with blood. Perfusion occurs when the heart is in systole, when the oxygenated blood is pushed into the arteries and is then carried to the tissues, where the oxygen is removed. The deoxygenated blood is returned to the heart by the veins, passing through the lungs to be re-oxygenated. Perfusion of the heart itself occurs during diastole, however, since this is when blood is pulled into the cardiac tissue. When perfusion does not take place as normal, it is referred to as malperfusion.
Perfusion is performed artificially during major surgeries such as open heart surgery. Health professionals known as perfusionists use mechanical blood pumps to push blood through the tissues while the heart undergoes the surgery. Several types of artificial perfusion exist for usage during major surgery on an organ that contributes to blood circulation. Extra-corporeal circulation (ECC) is when the blood is continuously pumped through plastic tubing to replace the circulatory function of the organ that is failing. A form of ECC is cardiopulmonary bypass, commonly known as a heart-lung machine, which takes over the job of the heart and lungs during surgery. Blood pumps, oxygenators, and hemodialysis are a few mechanisms used for artificial perfusion. Other types of artificial perfusion include extracorporeal membrane oxygenation, which is a life-support system used to improve cardiac and respiratory function in individuals whose bodies are unable to perform perfusion properly.
Bibliography
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