--- title: The heart and blood — a lesson of Mova's school · trees and pragmatics description: «The heart and blood», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Put your hand flat on your chest and you feel it: thump, thump, your heart, a muscle about the size of your fist that never stops working from before --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / The heart and blood # The heart and blood Lesson 65 of the biology course of Mova's primary school: 18 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/65-the-heart-and-blood/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/0/) — Put your hand flat on your chest and you feel it: thump, thump, your heart, a muscle about the size of your fist that never stops working from before you are born. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/1/) — Each beat squeezes blood out through tubes called arteries to every part of you, then the blood comes back through veins, round and round in a loop, carrying oxygen and food and taking waste away. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/2/) — Through a doctor's stethoscope the beat sounds like «lub-dub»: that is not the muscle squeezing but little doors, the valves, snapping shut so the blood can only go one way. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/3/) — Blood is always red, bright red with oxygen and dark red without, even though veins look blue through your skin. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/4/) — The heart grows stronger with exercise like any muscle, and it looks nothing like the heart on a Valentine's card. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/5/) — The heart is a muscle about the size of your fist, in the middle of the chest tipped a little to the left, and it beats about 100,000 times a day. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/6/) — The lub-dub sound is the heart's valves snapping shut: «lub» when the valves between the upper and lower chambers close, «dub» when the valves at the exits close. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/7/) — The pulse is the stretch of an artery each time the heart pumps; you can feel it on the wrist or neck, and it gets faster when you run, because working muscles need more oxygen; a fright makes it faster too, as the body gets ready to run. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/8/) — Blood is a yellowish liquid called plasma carrying red cells, white cells and platelets; a drop the size of a pinhead holds about 5 million red blood cells. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/9/) — Red blood cells carry oxygen using iron-rich haemoglobin, white cells fight germs, and platelets help stop bleeding. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/10/) — Blood is always red: bright red with oxygen and darker red after giving it away; veins only look blue because of how light passes through skin. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/11/) — The heart pumps blood out through arteries, into tiny capillaries and back through veins; its right side pumps blood to the lungs and its left side pumps it to the rest of the body. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/12/) — In 1628 William Harvey showed that the same blood goes round and round the body, when many people still believed blood was made fresh in the liver and used up; but the heart pumps more blood in an hour than food could ever make. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/13/) — When you cut yourself, platelets stick together at the cut and threads of a protein called fibrin form a net that traps blood cells into a clot, which dries into a scab. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/14/) — An adult has about 5 litres of blood, and healthy adults can give about half a litre at a blood donation to help people after accidents, operations and some illnesses. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/15/) — A giraffe's heart weighs about 11 kg and pumps at about twice the pressure of ours to push blood some 2 metres up its neck to the brain, and special blood vessels in its neck stop it fainting when it lifts its head after drinking. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/16/) — The heart gets stronger with exercise and then pumps more blood with each beat, so fit people often have a slower heartbeat at rest. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/65-the-heart-and-blood/17/) — A real heart is shaped more like a rounded cone with big tubes coming out of the top; the Valentine heart is only a drawing. - ← previous: [Cells, bones and muscles](https://md.mova.elamur.ai/free/en/corpora/school/biology/64-cells-bones-and-muscles/) - next →: [Lungs and breathing](https://md.mova.elamur.ai/free/en/corpora/school/biology/66-lungs-and-breathing/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)