The Heart
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The Heart by Sarah Bigam Did
you know?
Where the Blood GoesBlood is carried through your body in a certain way. The right ventricle beats. This forces blood into a large artery that carries the blood to the lungs. The red cells in the blood take oxygen from the air breathed into the lungs. From the lungs, blood is carried back to the heart through the veins. The blood then enters the left auricle. It passes through a valve into the left ventricle. The left ventricle beats. This forces blood into another large artery. This artery divides into smaller and smaller arteries. The smallest arteries are called capillary arteries. From the capillary arteries, blood carries food and oxygen to body cells. The blood also removes carbon dioxide and other wastes from the cells. The tiny capillary arteries connect with tiny capillary veins. These veins connect with larger and larger veins as they lead nearer to the heart. Blood is carried to a large vein that leads to the right auricle of the heart. From the right auricle, blood passes through a valve into the right ventricle. The blood has now made one complete trip through your body. This is repeated more than 1,000 times every day of your life.
The human heart is a muscle about the size of a fist. Its job is to pump blood around the body at the rate of 10 litres a minute. The heart beats around 3 billion times in an average person's lifetime. Can you fill in the missing labels?
Sarah recommends you check out the Heart Site at the Franklin Institute: http://www.fi.edu/biosci/heart.html My Heart shared by Sean Ritter My heart is a strong pump that moves blood through my body. It hangs in the center of my chest and is about the size of my fist. My heart works all the time, even when I am sleeping. It pumps blood that is full of oxygen and food through tubes called arteries. This fresh blood travels to all my cells and feeds them. My blood also cleans my cells. My cells give the blood carbon dioxide and other things they can't use. Then, my blood moves back to the heart through tubes called veins. My heart pumps this used blood to my lungs. My lungs take out the carbon dioxide and put in new, fresh oxygen. Then, my blood goes back to my heart to work again. It takes about one minute for my heart to circulate blood around my body and back again. This is called circulation. I can hear my heart working all the time. The beating sound my heart makes is caused by the opening and closing of the valves inside my heart. These valves are like doors. They let blood in and out of the heart. So, when I hear or feel my heart beating, I know my blood is circling all around my body. My heart moves the blood to clean and feed my cells.
Words You Should Know by Sarah Bigam arteries:
tubes that carry blood away from the heart to other parts of the body. blood vessels: tubes that carry blood to all parts of your body circulation: movement of blood through the body in a certain pattern plasma: the light yellow liquid part of blood platelets: round-shaped cells in the blood to stop bleeding from open cuts tissue: a group of the same kinds of cells that work together to do a certain job urine: fluid waste material released by the kidneys valve: a flap between chambers of the heart that opens to let blood pass through, then closes to stop blood from flowing backward veins: tubes that carry blood from parts of the body back to the heart ventricles: the lower left and right chambers of the heart
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