 This is the first video in a series on the cardiovascular physiology of the heart. In this video, I will describe the major functions of the cardiovascular system. Transport is the major function of the cardiovascular system. And so all of the other functions of the cardiovascular system can be related to the major function of transport. For example, the blood transports erythrocytes that are also known as red blood cells. And this is a mechanism to transport oxygen. Oxygen is transported inside of the erythrocytes and oxygen is being transported from the lungs to tissues throughout the body that use that oxygen as a nutrient necessary for aerobic cellular respiration. Aerobic cellular respiration produces carbon dioxide as a waste product that is then transported in the blood to the lungs where the lungs can remove carbon dioxide from the body. Platelets, also known as thrombocytes, are cell fragments that work to help stop bleeding in the mechanism of hemostasis. Lucocytes, also known as white blood cells, are transported in the blood around the body and help to defend against infection. Hormones are chemical messages secreted by endocrine glands into the blood and the blood then transports hormones around the body to bring the hormones to the target cells that are responding to the hormones. The blood transports nutrients from the intestines as we absorb nutrients from our food. Nutrients are transported in the blood around the body to deliver those nutrients to cells that can use them and as cells produce waste, this waste can be transported in the blood to organs that can help remove waste from the body. For example, the kidneys can help to remove waste from the body and produce urine to eliminate that waste as we excrete the urine out of the body. Heat is another thing transported by the blood. So the mechanism maintaining body temperature, the thermoregulation mechanism, involves regulating blood flow. If we have increased blood flow to the skin, that will help to cool the body down as heat is radiated away from the blood. Whereas redirecting blood flow deep away from the skin will help to reduce this heat loss helping to increase the body temperature.