The heart of an amphibian, such as a frog, has three chambers, one ventricle and two atria. Blood from the ventricle travels to the lungs and skin where it is oxygenated and also to the body. In the ventricle deoxygenated and oxygenated blood are mixed before being pumped out of the heart. This is a very inefficient method when compared to the mammalian heart. Amphibians, however, have lower metabolisms hence they require less. Requiring less oxygen puts less demands on the heart to deliver blood of high oxygen concentration. So a heart with three chambers is ideal for the needs of amphibians who could also absorb oxygen through their skin when moist. Mammals and birds, however, have a higher metabolic rate so must have a way of delivering more oxygen per litre of blood to the body than amphibians.
Every second of every day something incredible happens inside your body. One of your body\’s organs, the HEART, works day and night to constantly pump blood into your lungs where it loads up on oxygen, and then pumps blood out to the rest of your body where it delivers nutrients and oxygen and removes waste products. If this finely tuned engine stopped you\’d be dead in minutes! Let\’s investigate the heart\’s, and, uncover what they do and how they work! Where is your heart? Your heart is in the center of your chest. Your heart is not right under your skin but lies behind your breastbone, inside your ribcage and between your lungs.
Take a closer look its. How big is your heart? The heart is about the size of your fist. When you were a baby it was the size of your baby fist. What does the heart look like? The heart is a muscle, just like the other muscles in your body!! It weighs about a pound, or less than half a kilogram. What are the heart\’s chambers? The heart has four chambers, which you can think of as rooms of the heart. There are two ( A in the picture) and two ( V in the picture). The atria receive blood from the body and the lungs, and the ventricles pump blood back out, first to the lungs and then to the body. Read more about, then. What does the heart do? This muscle, which beats at about 70 times a minute, pumps blood in a one-way path around your body through blood vessels. The heart and the vessels together are called the. The stop blood from flowing the wrong way. The heart pumps thousands of liters of blood through your body every day. Blood is pumped out of the heart in two directions. First it sends blood without any oxygen from the right ventricle to the lungs to get oxygen. After the oxygen-filled blood comes back to the heart to the left atrium it is pumped from the left ventricle to all the other parts of the body. After delivering its oxygen, the blood returns to the heart to the right atrium to start the process of getting oxygen all over again.
Watch your through the heart. What do the valves do? Between the chambers there are valves which stop blood from flowing the wrong way. The valves open and close and help to move blood through the heart to the right place at the right time. When the valves open, blood surges into the chambers. The valves close, the heart contracts, and the blood flows out. as blood flows through the heart. For another view, watch this. The human heart beats over two and a half billion times in a lifetime. The heart\’s rate when you are a baby is about 120 beats per minute. As you grow, your heart rate slows. A seven year old child\’s heart beats about 90 times per minute. By the age of 18, the heart rate is about 70 beats per minute. Listen to the of a heart at rest and after exercising. During exercise, more oxygen and nutrients are needed by the muscles, so blood must be delivered faster than when the body is resting. To meet these demands, the heartbeat increases. You can find your heartbeat. There are places on your body where you can feel your pulse, the beat of blood as it rushes through your veins and arteries. Your wrist is a good place to try. Continue your tour by visiting and. Are all hearts the same? Did you know that all hearts are not the same? A mammal heart is different from a fish heart, for example, even though both mammals and fish are vertebrates.
Birds and mammals (humans are mammals) have a 4-chambered heart that separates oxygen-rich and oxygen-depleted blood. Fish have a 2-chambered heart. Amphibians have a 3-chambered heart with two atria and one ventricle. Some reptiles have a partial separation of the ventricle but others have a 4-chambered heart. Who knows about the heart? A Cardiologist is the special doctor who knows about the heart and circulatory system, and about its functions and diseases. Read about the. While there have been many medical breakthroughs in treatments of heart disease, including surgery and transplants, a large number of people still die from heart-related illnesses each year. Watch an. About 610,000 people die of heart disease in the United States each year. The average age for a first heart attack is about 65 for men and 72 for women. About 735,000 people in the U. S. have heart attacks (myocardial infarctions) each year. Of those, about 120,000 die. Learn about. What can you do to keep a healthy heart? Those who are at a higher risk of suffering a heart attack or stroke (brain attack) are theose who are overweight, are smokers, have high cholesterol, high blood pressure (hypertension), or diabetes. Follow these to have a healthy heart for the rest of your life.