Your body你的身体
Heart and blood 心脏和血液
Circulatory system 循环系统
All parts of your body need nutrients营养物(from food)and oxygen氧气.Your circulatory system (循环系统)takes nutrients营养物and oxygen氧气 to where they are needed.It also carries waste(废物) away.
Your circulatory system includes your heart, blood vessels血管 and blood.
☞Your heart (心脏)is a strong muscle. It pumps blood around your body. It beats about 70 times every minutes.
☞Your blood(血液) is mainly water. Nutrients dissolve溶解 in the water. Blood also includes 包括 red blood cell 血红细胞 to carry oxygen 氧气.
☞Blood travels through tubes(管) called blood vessels血管.
Blood vessels
There are different types of blood vessel, including arteries (动脉)and veins(静脉).
☞Arteries(动脉) carry blood aways from your heart to all other parts of your body.
☞Veins(静脉) return blood to the heart.
One artery(动脉)joins your heart to your brain. It carries blood that is rich in oxygen(氧气)and nutrients(营养物). Your brain removes the oxygen and nutrients that it needs. It replace(替代)them with waste (废物)substances(物质). The blood takes this waste away.
