Instructional design of "What happens when you exercise (1)"

(1) scientific concept:

Human body needs oxygen to exercise, exchange gas in the lungs, absorb oxygen and excrete carbon dioxide.

2. The more people exercise, the more oxygen they consume, so it is necessary to speed up the breathing in the lungs to inhale more oxygen.

(2) Process and method: 1. Reasonable data analysis.

2. Combined with the experimental phenomena and related data, the reasons for the accelerated breathing times were analyzed.

(3) Emotion, attitude and values: 1. Willing to communicate with classmates, able to cooperate to complete experimental activities. 2. Recognize the necessity of patiently and meticulously completing measurement activities.

Second, the focus and difficulty of teaching

Teaching emphasis: verify the change of gas before and after breathing by experience and experiment.

Third, teaching preparation.

1. Student preparation: marker or watercolor pen, pencil box;

2. Teacher preparation

Hand out before class: paper used to record the number of breaths.

Midway distribution 1: information about respiratory organs.

Midway delivery 2: fresh-keeping bag.

Distribution 3: (1) Water tank, straw and lighter halfway. One for each table; (2) Gas cylinders, wool slideways and bamboo sticks. 2 copies of each form;

Teacher's materials: courseware, a bottle of "carbon dioxide" (labeled), clock (standby)

Five, talk before class:

The teacher demonstrated the habit of blowing air in the sink. Q: What do you see on the water? (Bubbles), is there any way to blow in the water without seeing bubbles on the water? (Or ask: Is there any way to put these bubbles together? ) → The teacher demonstrates the specific operation of "draining water to get gas".

Intention: enliven the atmosphere, narrow the distance between teachers and students, and pave the way for the method of "draining water to get gas"

Attention: cultivate students' observation ability and get a preliminary understanding of the collection method of drainage gas.

teaching process

First, measure the heartbeat and breathing times before and after exercise.

Teacher: Do children like sports?

Teacher: What sports do you like?

Teacher: How do you feel after exercise? (Understand students' original cognitive level)

(Show topic: What happens when you exercise? )

Teacher: It's cold today, too. The teacher decided to let everyone move together. But before practice, the teacher should assign a task:

Read the record sheet on page 69 first, understand? What does this form let us do?

measure

(1) guidance

Teacher: How should we measure it? If we keep breathing, how can we count as one?

Preppie: Inhale to Exhale (please demonstrate)

Teacher: You should also be careful not to deliberately control your breathing when measuring, and the measuring time should be the same, so you should record it in time.

Teacher: How to measure the heartbeat?

Health preset: feel the pulse on your hand and feel your heartbeat.

Teacher: Let's feel the heartbeat together.

(Students touch their heartbeat and pulse)

Teacher: Tell me about the heartbeat you feel.

Teacher: We learned how to measure breathing and heartbeat, but both should be recorded in one minute. Is there any good way to make our measurement data more accurate?

(2) measurement

Teacher: The teacher has a better way. Do you want to know? The teacher thinks that two students measure their breathing for a group of students who ask to go first, and the students on the right measure the heartbeat of the students on the left. After one minute, let the students on the left do a squat for one minute, and then measure their heartbeat and breathing according to the original method! what do you think?

Teacher: Let's go! Students look at the clock on the big screen and freely measure the number of breaths before and after exercise and record them. Teachers participate together.

Courseware prompt: (time with small clock)

First measure the number of breaths and heartbeats in one minute when you are calm. (Be careful not to intentionally control it and record it. )

Exercise in the same place for one minute, please pay attention to safety! Ask the students to do a squat exercise.

After exercise, stand and measure the breathing and heartbeat after one minute and record it in time. (Measure and record when the time is up)

Finally, what do you find by comparing these two data?

Children's heart beats 80-90 times per minute, while adults are flat? 70-80 times per minute. 8 ~ 14 years old breathes 20 ~ 16 times per minute, which is close to that of adults. )

(3) Discussion

The teacher immediately draws three sheets of recording paper and shows them in turn. )

Teacher: What do you find by comparing the data of these two? ?

Health: After exercise, you will breathe faster and your heart will beat faster.

Teacher: If you agree with their group, please raise your hand! (blackboard writing: breathing will accelerate after exercise)

Design intention: Let students draw the conclusion that breathing and heartbeat will accelerate after exercise through personal experience and data comparison, and question why it will accelerate.

Second, the experiment explores why breathing will accelerate.

1. Discussion

Teacher: We breathe all the time. With the increase of exercise, the number of breaths per minute will also increase. What is the relationship between exercise and breathing? Have some discussion in the group.

Tour guidance of student discussants

Health report

Objective: To pay attention to students' thoughts and arouse their mutual doubts. It is best to guide students to think of breathing, so that we can get substances beneficial to our health from the air.

2. Student experience: Breathing the same bag of air repeatedly.

Teacher: What is this substance? Are the gases we breathe in and out the same?

Health: It's different.

Teacher: Is it really different? Come and experience it. Fill the bag with air, insert a straw in the bag, and tie the bag mouth tightly with a rubber band. Breathe the air in the bag repeatedly. How does it feel? Think about what this means. Note: Stop the experiment as long as there is obvious feeling. (big screen prompt)

Students report after experiencing activities.

Teacher: How do you feel? What does this mean?

Health preset: stuffy, hot and breathing gas are different.

Teacher (summary): It seems that the gas has really changed from inhalation to exhalation.

Design intention: Let students know that exhaled gas is different from inhaled gas through personal experience.

Concern: Do students feel that there is a difference between the air we breathe in and the air we breathe out?

3. Experiment: Observe the combustion of flame in two gases.

Teacher: Why are you bored and have difficulty breathing?

Health preset: insufficient oxygen.

Teacher: It's a pity that those are just human feelings. I wish I could see the different characteristics of this gas with my own eyes! Do we have any good ideas? Can other experiments be used to prove it? )

Let the students talk about their ideas first.

Teacher: The teacher thought of a good way to try it with lit matches.

Teacher: If you want to test them, you must collect them first. How do you collect them?

(Students answer, the teacher reminds us that the inhaled air is the air around us, which can be collected directly, and the exhaled air can be collected by drainage before class and demonstrated.)

Teacher: After collection, use two lighted matches to go deep into the bottle respectively, and pay attention to the same time. Observe what happens (the teacher guides and demonstrates, especially how to light and extinguish matches)

Student action teacher patrol

Teacher: What phenomenon have you observed?

Teacher: What does this mean?

Objective: To make students understand that inhaled gas supports combustion, while exhaled gas does not support combustion.

4. Learning materials: gas composition comparison table before and after breathing (oxygen decreases and carbon dioxide increases when breathing) (courseware display)

Teacher: Then let's see what we breathe out and breathe in. Let's look at the research data of scientists!

Teacher: Look at the pictures in turn. What kinds of gases are there? What kind of gas has changed? Which gas hasn't changed? How did it change?

Teacher: From these changes, we can know that "human breathing is actually exchanging gas, absorbing oxygen and expelling carbon dioxide from the body." (Courseware shows that breathing is actually a process of gas exchange) Which organs will this gas pass through when it enters the body? In which organ of the human body is gas exchanged? )

Teacher: Actually, the outside air enters the trachea through the nasal cavity, and then reaches the bronchi and lungs through the trachea for gas exchange. Then the exchanged gas passes through the bronchus, trachea and nasal cavity to the air (let the students take a deep breath, feel and point)! (Courseware shows respiratory organ diagram)

Teacher: Students can also see the diaphragm structure in the picture, which also plays a great role in breathing. It can make the chest expand and contract while better completing the breathing action!

Teacher: If we enlarge the alveoli, we will magically find alveoli. In fact, alveoli are the real gas exchange places. That is to say, the outside air enters the trachea through the nasal cavity, reaches the bronchus through the trachea, and exchanges gas with the lungs in the alveoli, and then the exchanged gas completes a gas exchange with the air through the bronchus, trachea and nasal cavity!

Three. Summary and expansion

1. Summary

Teacher: Today we learned about exercise and breathing. Did you get anything?

Teacher: Breathing will accelerate after exercise; Exercise requires a lot of oxygen, so breathing will be accelerated; Regular exercise will exercise our respiratory organs, improve our breathing ability and get more oxygen. So regular exercise is good for your health.

2 expansion

Teacher: Do you want to know whether your breathing ability is strong or weak? We can test everyone's "vital capacity" (vital capacity refers to the total amount of gas exhaled after trying to inhale once. The amount of vital capacity reflects our breathing ability.

Suggestions for extracurricular activities: (1) Make a self-made vital capacity measuring device to measure your current vital capacity and compare it with the students of a tennis team in a school. What is the difference? (or, after a month of exercise, measure your vital capacity again. (2) Compare a classmate who loves sports with a classmate who doesn't love sports, and measure how long it takes them to return to their original breathing times in a calm state after jumping 1 minute. What's the difference between comparison and comparison? See if we can explain this phenomenon.