The Heart

The Way Your Body Works

Structure

The cardiac muscle contracts and relaxes at average about 70 to 80 times per minute. As it contracts it also pushes your blood through chambers and vessels. The heart weighs about 11 ounces and stays the size of your fist as you grow. The heart will be located in the chest behind the breastbone between the lungs. It can be found in a chamber called the pericardial cavity surrounded by the rib cage. The atrias are separate from each other just like the ventricles. Your heart is shaped like an upside down pear and is primarily a shell. There is two atrias and ventricles also there is four cavities which are open spaces in the heart. You can find your atrias at the top of the heart and ventricles at the bottom of it. The septum a wall separates the left side from the right. You can feel your heart better on the left side of your chest because the left ventricle contracts more forcefully. The mitral value connects the left atrium and ventricle and the tricuspid value connects the right atrium and ventricle. The largest vessel is the aorta which sends nutrient-rich blood away from the heart. The pulmonary artery connects the heart and lungs. The two largest veins are the vena cava its name means heart`s veins. They carry blood into the heart. The superior vena cava is located at the top of the heart while the inferior is located below the superior.

Blood

Blood travels through your veins giving you essential elements and removing harmful waste. It transports oxygen from the lungs to body tissues and carbon dioxide from body tissue to the lungs. It will transport nourishment from digestion and hormones from glands throughout the body. It will also send disease fighting substances to body tissues and waste to kidneys. Blood is alive containing cells. Red and white cells clean and nourish our body. The blood cells also require nourishment. Vitamins and minerals keep our body healthy by feeding our blood with nutrients. Our cells also have a life cycle. 55% of our blood is plasma which is a straw colored clear liquid. they carry solid cells and platelets which when you get a wound will clot the blood and stop you from bleeding. Blood is constantly being made so it can be replaced.There are four types of blood and our blood has RH factors meaning our blood is not the same. Blood vessels are hollow tubes for carrying blood. The three types of vessels are arteries,veins, and capillaries. An artery carries blood away from your heart, the capillaries connect the arteries to veins, and the veins carry blood back to the heart. An adult`s vessels would be close to 100,000 miles long.
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Pulse

We measure pulse by touching an artery. The rhythmic contraction of the artery is near the surface of our skin while the heart is deeply protected. That is why we use arteries instead of the heart, to get a more accurate pulse.