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Unit 1 – Cells and Cell SystemsGrade 8 ScienceStudent Copy1.8 – The Heart8-1-11Describe the structure and function of the heart and the path of blood to and from the heart through its four chambers.Key Vocabulary: atria, ventricles, septum, valves, aorta, pulmonary artery, pulmonary veins, superior vena cava, inferior vena cava.Read p. 79 - 87Amazing Heart FactsHold out your hand and make a fist. If you’re a kid, your heart is about the same size as your __________, and if you’re and adult, it’s about the same size as ____________ fists.Your heart beats about _____________________ times in one day and about _______________________ times in a year. During an average lifetime, the human heart will beat more than ________________________ times.Give a tennis ball a good, hard squeeze. You’re using about the same amount of _______________ your heart uses to pump blood out to the body. Even at rest, the muscles of the heart work hard---twice as hard as the _____________ muscles of a person sprinting.The heart weighs between ______ and _______ ounces (200 to 425 grams) More about the Heart Your heart is an organ made of ______________ muscleYour heart has ________ cavities called ___________________The two _____________ chambers are called the right and left _________________The two _________________ chambers are the right and left ________________________Blood flows into the heart through the _______________ and then out through the ___________________91440027559000Blood Vessels8-1-12 Compare and contrast the structure and function of arteries, veins, and capillaries.Blood vessels are the passage way in the ________________________ system. There are 3 main types of blood vessels:Arteries - carry blood ___________________ the heartVeins - carry blood ___________________ the heartCapillaries - the ______________________ blood vessel - connects _________________ to ______________ - where gas, nutrient/waste _______________________ occursBlood is carried from your heart to the rest of your body through a complex network of __________________ and ___________________. Blood is returned to your heart through _______________.The process of blood flow within your body is called _______________________. ______________________ carry oxygen-rich blood (blood carrying lots of oxygen) _________________ from your heart. The exception to this are the pulmonary arteries which carries oxygen poor blood away from your heart to your lungs.__________________________carry oxygen-poor blood (blood carrying little oxygen) _________________ to your heart. The exception to this are the pulmonary veins which carries oxygen-rich blood back to your heart from your lungs.________________________connect arteries and veins. They are tiny tubes that exchange _______________, _____________________ and ________________ between ____________________ and body _______________. Arteries, Veins & CapillariesArteriesCapillariesVeinsBlood DirectionMuscle LayerSemilunar ValvesPressureOxygen Concentration(Typically)The arteries have "pulse" which means that the blood moves in ____________, according to when the heart _____________. When the blood enters capillaries, it moves smoothly, and so it carries this flow on to the veins.Looking at the image from above, you can see that they have different _________ ________________. The capillary wall is only 1 cell thick - this is to allow substances to _______________ across it (ie. to give ________________ to cells and retrieve the ___________ from cells). One of the reasons the blood is at higher pressure in the arteries is that there is a ___________ muscle layer and this creates a __________ hole for the blood to pass through. The thick muscle layer is there to withstand the ____________ pressure. In the veins, the _______________ stop the blood from flowing ______________________, as it is traveling at a very _________ pressure and is often moving against _________________. The __________________ of the muscles also helps the blood in the veins to be pushed up.left16383000This image shows how veins have valves which stop the blood from flowing backwards. They are needed as there is so little pressure in them. The Cardiovascular SystemYour heart and circulatory system make up your _____________________ system. Your heart works as a _____________ that pushes blood to the ______________, ______________, and ______________ of your body. Blood delivers _________________ and ________________ to every cell and removes the _______________ _______________ and ____________ ________________ made by those cells. Blood is carried from your heart to the rest of your body through a complex network of __________________________ and ___________________. Blood is returned to your heart through _________________.Order of FlowSuperior Vena Cava (Blood coming from the upper portion of the body)orcenter21907500Inferior Vena Cava (Blood coming from the lower half of the body)center38544500Right Atriumcenter21018500Tricuspid Valvecenter19113500Right Ventriclecenter21272500Pulmonary Valvecenter21399500Pulmonary Arterycenter18669000Capillaries in your lungs (Gas exchange occurs CO2 => O2)center18732500Pulmonary Veincenter17907000Left Atriumcenter20891500Mitral Valvecenter19113500Left Ventriclecenter20193000Aortic Valvecenter18415000Aortacenter26162000Arteries297180020574000Capillaries (Gas exchange occurs O2 => CO2)Veins ................
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