![blood circulation of hydrophobic amino acids blood circulation of hydrophobic amino acids](https://ars.els-cdn.com/content/image/3-s2.0-B9780323661621000020-f02-01-9780323661621.jpg)
The aorta arches and gives branches supplying the upper part of the body after passing through the aortic opening of the diaphragm at the level of thoracic ten vertebra, it enters the abdomen. The first part of the systemic circulation is the aorta, a massive and thick-walled artery. Oxygenated blood enters the systemic circulation when leaving the left ventricle, through the aortic semilunar valve. The other component of the circulatory system, the lymphatic system, is open. In contrast, oxygen and nutrients diffuse across the blood vessel layers and enter interstitial fluid, which carries oxygen and nutrients to the target cells, and carbon dioxide and wastes in the opposite direction. The cardiovascular systems of humans are closed, meaning that the blood never leaves the network of blood vessels. Also, the digestive system works with the circulatory system to provide the nutrients the system needs to keep the heart pumping. Blood consists of plasma, red blood cells, white blood cells, and platelets. An average adult contains five to six quarts (roughly 4.7 to 5.7 liters) of blood, accounting for approximately 7% of their total body weight. The systemic circulation can also be seen to function in two parts – a macrocirculation and a microcirculation. It includes the pulmonary circulation, a "loop" through the lungs where blood is oxygenated and the systemic circulation, a "loop" through the rest of the body to provide oxygenated blood. The essential components of the human cardiovascular system are the heart, blood and blood vessels. Vascular surgeons focus on other parts of the circulatory system. Cardiologists are medical professionals which specialise in the heart, and cardiothoracic surgeons specialise in operating on the heart and its surrounding areas. This includes cardiovascular disease, affecting the cardiovascular system, and lymphatic disease affecting the lymphatic system.
![blood circulation of hydrophobic amino acids blood circulation of hydrophobic amino acids](https://www.aimspress.com/aimspress-data/aimsmoles/2020/3/PIC/molsci-07-03-011-g003.jpg)
Many diseases affect the circulatory system. The more primitive, diploblastic animal phyla lack circulatory systems. The lymphatic system, in contrast, is an open system providing an accessory route for excess interstitial fluid to be returned to the blood. While humans and other vertebrates have a closed cardiovascular system (which means that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. The circulatory system of the blood has two components, a systemic circulation and a pulmonary circulation. The lymph, lymph nodes, and lymph vessels form the lymphatic system, which returns filtered blood plasma from the interstitial fluid (between cells) as lymph. The cardiovascular (from Latin words meaning "heart" and "vessel") system comprises the blood, heart, and blood vessels. Lymph is essentially recycled excess blood plasma after it has been filtered from the interstitial fluid (between cells) and returned to the lymphatic system. Blood is a fluid consisting of plasma, red blood cells, white blood cells, and platelets that is circulated by the heart through the vertebrate vascular system, carrying oxygen and nutrients to and waste materials away from all body tissues. The passage of lymph takes much longer than that of blood. The circulatory system includes the lymphatic system, which circulates lymph. The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.