Your body你的身體

Heart and blood 心臟和血液

Circulatory system 循環(huán)系統(tǒng)

All parts of your body need nutrients營(yíng)養(yǎng)物(from food)and oxygen氧氣.Your circulatory system (循環(huán)系統(tǒng))takes nutrients營(yíng)養(yǎng)物and oxygen氧氣 to where they are needed.It also carries waste(廢物) away.

Your circulatory system includes your heart, blood vessels血管 and blood.

?Your heart (心臟)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 血紅細(xì)胞 to carry oxygen 氧氣.

?Blood travels through tubes(管) called blood vessels血管.

Blood vessels

There are different types of blood vessel, including arteries (動(dòng)脈)and veins(靜脈).

?Arteries(動(dòng)脈) carry blood aways from your heart to all other parts of your body.

?Veins(靜脈) return blood to the heart.

One artery(動(dòng)脈)joins your heart to your brain. It carries blood that is rich in oxygen(氧氣)and nutrients(營(yíng)養(yǎng)物). Your brain removes the oxygen and nutrients that it needs. It replace(替代)them with waste (廢物)substances(物質(zhì)). The blood takes this waste away.