第3课

第三课

lesson three

心脏和血管

Heart and blood vessels

l 1.长胶管儿，玻璃漏斗，秒表等 。

Long rubber tube, glass funnel, stopwatch, etc.

2.测一测我们的脉搏 。

Take our pulse.

我们的记录

Our records

同一个人不同状态，静坐运动，轻微运动，剧烈运动，脉搏跳动次数 （1分钟 ）

Different states of the same person, sedentary exercise, light exercise, strenuous exercise, pulse beat times (1 minute)

（1）脉搏的跳动是由什么引起的 ？

What is the cause of pulse beating?

资料卡

index card for files

人在情绪激动 、从事体力劳动或参加体育运动时 ，心跳会明显加快 。若人体某一器官发生病变 ，也常会使心跳发生快慢 、强弱的变化 。不同年龄的人 ，心跳会有不同  少年儿童在正常情况下 ，每分钟心跳60~100次 。

When people are emotional, engaged in physical labor or participate in sports, their heartbeat will be significantly accelerated. If a certain organ of the human body has pathological changes, it often makes the heart beat fast, slow and strong. People of different ages have different heartbeat. Under normal circumstances, children's heartbeat is 60 ~ 100 times per minute.

3.找一找我们的心脏和血管 。

Look for our heart and blood vessels.

（1）血管在我们身体的……

Blood vessels in our bodies

     血管在于胸腔左侧 。它的形状像一个倒置的梨 ，上大下小 ，大小和自己的拳头差不多 。心脏的内部有4个腔 ，分别为左心房、右心房、左心室、右心室。

The blood vessel is on the left side of the chest. It's shaped like an inverted pear, big at the top and small at the bottom, about the size of its own fist. There are four chambers in the heart: left atrium, right atrium, left ventricle and right ventricle.

     血管是血液在全身循环时所经过的管状构造 ，遍布人的全身 。血管分为动脉，静脉和毛血细管 。

Blood vessels are the tubular structures through which blood circulates throughout the body. The blood vessels are divided into arteries, veins and capillaries.

（2）心脏总是在有规律的收缩和舒张 。收缩时， 心脏把血液压入动脉 ；舒张时 ，血液从静脉流回心脏 。心脏不停的收缩和舒张 ，从而推动全身的血液不停地流动 。先找每收缩和舒张一次 ，我们就感觉到心跳一次 。

The heart always contracts and relaxes regularly. During contraction, the heart presses blood into the arteries; During diastole, blood flows from the vein back to the heart. The heart constantly contracts and relaxes, thus impels the whole body's blood to flow unceasingly. First look for every contraction and relaxation, we feel a heartbeat.

     血液把消化器官吸收的养料和呼吸器官收缩的氧气运送到全身各处 ，又把全身各处产生的二氧化碳等废物运走 ，交给呼吸器官 、排泄器官排出体外 。

Blood transports the nutrients absorbed by digestive organs and oxygen contracted by respiratory organs to all parts of the body, and transports the carbon dioxide and other wastes produced throughout the body to respiratory organs and excretion organs to be discharged from the body.

l 4.怎样保护我们的心脏和血管 ？

How to protect our heart and blood vessels?

①高血压，心脏病，动脉硬化是常见的心血管疾病 。

Hypertension, heart disease and arteriosclerosis are common cardiovascular diseases.

②科学饮食，少吃高脂肪，高蛋固醇的食品 。

Scientific diet, eat less high fat, high egg sterol food.

③经常参加体育锻炼可以增强心脏的功能 。

Regular physical exercise can enhance the function of the heart.

④不吸烟，不饮酒 。

No smoking, no drinking.

l 制作一个简易听诊器 。

Make a simple stethoscope.

（1）我来试一试。

Let me have a try.

5.测一测不同年龄，不同性别的人的心跳 。你有什么发现 ？

Measure the heartbeat of people of different ages and genders. What do you find?