Emerald Robinson: Hi! I'm Emerald Robinson and in this What is? video, well look at the human bodies delivery network, the cardiovascular system. The cardio vascular system is the organ system that can consist of the heart, the blood, and the vessels that carry the blood throughout the body.
The primary function of this system is to deliver oxygen and nutrients to cells and then carry waste products away from them. Blood is made up of a watery straw colored fluid called plasma. And there are three types of cells that float in it. Donut shaped red blood cells transport carbon-dioxide and oxygen. They also give red its red color. White blood cells or leukocytes fight infection and platelets stop bleeding after an injury by clubbing together or clotting.
Blood flows through the body through three main kinds of vessels. Arteries carry blood away from the heart and have sturdy walls to withstand its pumping pressure. Veins carry blood back to the heart and have valves to prevent blood from flowing backwards. And capillaries function by allowing that a fusion of materials through their thin walls either into or out of the blood stream.
The heart is the muscular four chambered pump that pushes the blood through the vessels. Oxygen pour blood returning from its trip through the body enters the hearts right atrium, passes through a valve into the right ventricle and travels to the lungs to pick up oxygen.
Oxygen aid the blood returns to the heart filling the left atrium first then, the thick wall that left ventricle. From there, it's pumped to the rest of the body through a large artery called the aorta. The cardiovascular system also performs the lesser known function of helping to regulate our body temperature. When we are warm, the blood vessels, right under the surface of our skin become more open or dilate, releasing heat to the air. When we are cold, the vessels become more closed, keeping more heat inside our bodies.