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• The circulatory system is one of the most important systems in the human body, transporting the needed blood and nutrients throughout the body.
• The circulatory system consists of the heart, blood, and blood vessels.
• The circulatory system is a transport system of the body, responsible for the distribution of blood and other nutrients throughout the body.
• The circulatory system is made up of heart, blood, and blood vessels.
• There are three types of blood vessels in the body: veins, arteries, and capillaries, which carry oxygenated and deoxygenated blood.
• The blood is the liquid part that is constantly flowing throughout the body, composed of a liquid part called plasma and the solid parts of formed components which are the red blood cells, white blood cells, and platelets.
• The red blood cells, also known as erythrocytes, transport gases to and from the cells.
• The white blood cells, or leukocytes, play a vital role in the body's immune system, fighting bad bacteria, viruses, and others that cause infection.
• The last formed components of blood are the platelets or thrombocytes, which are the smallest of formed components of blood that help in blood clotting.
• The blood vessels are the vast networks of small tubes that carry blood throughout the body, with arteries carrying oxygen-rich blood away from the heart, veins carrying deoxygenated blood back to the heart, and capillaries serving as a connection between arteries and veins.
• The circulatory system has two types of circulation: the pulmonary circulation, which is the movement of deoxygenated blood from the heart and into the lungs, and the systemic circulation, which is the movement of oxygenated blood from the heart to the different parts of the body.
• The heart, known as the pumping organ of the body, keeps the blood moving throughout the body and has four chambers: the left and right atrium which are responsible for receiving used blood coming from all parts of the body, and the left and right ventricles which are the pumping chambers.
• Between the atrium and ventricles of the heart are valves, which allow blood to flow in one direction.
• Oxygen-poor blood enters the heart through two large veins, the inferior and superior vena cava, emptying blood from the body into the right atrium of the heart.
• As the atrium contracts, blood flows from the right atrium into the right ventricle through the open tricuspid valve.
• When the ventricle is full, the tricuspid valve shuts, preventing blood from flowing backward into the atria while the ventricle contracts.
• As the ventricle contracts, oxygen-rich blood leaves the heart through the pulmonic valve into the pulmonary artery into the lungs where it is oxygenated.
• Oxygen-poor blood enters the heart through the pulmonary vein, emptying oxygen-rich blood from the lungs into the left atrium of the heart.
• As the atrium contracts, blood flows from the left atrium into the left ventricle through the open mitral valve.
• When the ventricle is full, the mitral valve shuts, preventing blood from flowing backward into the atria while the ventricle contracts.
• As the ventricle contracts, oxygen-rich blood leaves the heart through the aortic valve into the aorta to the arteries and eventually into the veins to complete the blood circulation in the body.
• The circulatory system is a good example of how body systems interact with each other to keep the body alive, with each organ of the system working together to circulate blood throughout the body.