DON'T TAKE MY BREATH AWAY

DON'T TAKE MY BREATH AWAY!

Knight Foundation Summer Institute

Liane D'Alessandro, Haverford College

Introduction:

This lesson is designed to encourage students to think about their life -- i.e., to notice what happens to their bodies as they go about their daily activities and then to ask questions about why and how they occur. The lesson is based on sports; most students can relate to some sort of physical activity whether it be roller blading, playing basketball, running, jumping rope, walking, dancing, or the like. Specifically, for this lesson, questions generated by the students about what happens to their bodies while they play sports will help them to understand the respiratory system. What is the respiratory system? It is a group of structures in the body that work together to bring oxygen into the body. But why do our bodies need oxygen ? Our bodies use oxygen to make energy so that we can play all those fun sports. But what does oxygen have to do with energy? Well, once the oxygen enters the body through the nose or mouth, it travels to the lungs and eventually to the bloodstream. Once in the bloodstream, the heart pumps the oxygen-rich blood to all the cells in our body. In the cells, a series of chemical reactions occur to produce the energy. One of the most important reactants in these chemical reactions is oxygen. When oxygen reacts with other compounds, such as the food we eat, energy can be produced. This series of chemical reactions also produces carbon dioxide. But the body has no use for the carbon dioxide, so it leaves the cell and enters the bloodstream. The heart pumps the carbon dioxide back to the lungs where it is exhaled.

So the first step is to get the students curious about the respiratory system by connecting it with playing sports. Perhaps one way to get them interested is first to have a discussion about sports in general. For example, the teacher could start off by asking the students what sports they like to play. This could then lead to a discussion about who their favorite athletes are and why. Next, the discussion could lead to why certain athletes are better than others; that is, how do athletes stay in shape? Maybe at this point, some students could share experiences of what it's like to be in shape or out of shape. For example, maybe the students recognize that they breathe really heavily while playing sports, either when they are out of shape, or when they get tired. The teacher may then ask them if they have ever tried to play a sport without breathing. (Don't encourage them to do this though.) Why can't someone play sports without breathing? Why does breathing get heavy when you are out of shape or when you are tired? These are all questions that the class could generate during the discussion. And perhaps they will come up with even more questions about the respiratory system that they want to have answered. Activity #1 below is one way to help the children relate sports to the respiratory system, that is, they will begin to see how delivering oxygen to the muscles is a necessary component of playing sports.

Objectives for Activity #1:

To learn how to find one's pulse rate and breathing rate

To determine how pulse rates and breathing rates change under various conditions

To begin to generate questions about the respiratory system

Vocabulary for Activity #1:

(resting) pulse rate

(resting) breathing rate

Materials for Activity #1:

timer with second hand

appropriate clothing for jumping jacks (or any physical activity the students would prefer)

pencil and paper to record observations

Procedure for Activity #1:

Teach the students how to take their pulse by first having them locate their pulse. There are two main ways to do this. One is to take the index and middle fingers and to find the pulse in the neck. (Turn head sideways and place fingers in front of the part that sticks out; then turn head back to the front). The next way is to locate the pulse in the wrist. (Slide the same two fingers down the side of the thumb until the pulse is felt in the wrist). Once each student has located the pulse, explain that they will count the number of beats they feel for 10 seconds and then multiply this number by "6" to get their heart rate for one minute. The easiest way to do this may be to have the teacher say, "Go!" and ten seconds later, "Stop!". During this time the students would count their own pulses.

After each student has determined how to take their pulse rate, teach them how to take their breathing rate for one minute (counting the number of breaths they take normally in 20 seconds and multiplying by "3"). Again the teacher should keep track of time while the students count.

Have students record their pulse rate and breathing rate in their notebooks after sitting down for a while. This is their "resting pulse rate" and "resting breathing rate".

The next step is to have the students determine how their pulse and breathing rates can change. Ask them to think of what they can do to increase their pulse and breathing rates. For example, you may ask them how would their pulse rate would change after ten minutes of running around on the playground. Encourage the students to come up with their own physical activity (maybe pushups, sit-ups, jumping jacks, etc.) that they can do in the classroom to alter their pulse and breathing rate. Have them perform this activity (as long as its reasonable) and to record their new pulse rates and breathing rates.

After performing this warm-up, hold a class discussion about what physical activities the student chose and how the rates changed as a result of the activity. Let this be a time for the students to generate further questions such as, "Why does the pulse rate and breathing rate change in that particular way?" To relate it to sports, during periods of exercise, our bodies need more energy and since our bodies use oxygen to make energy, more oxygen must be taken in during exercise. Therefore, we inhale more frequently. The heart, then, begins to pump faster to deliver the increased amount of oxygen to the cells. This causes the pulse rate to increase. As the cells use this oxygen to produce energy, more carbon dioxide is also produced. Therefore, we exhale more. But for the students to understand that explanation, they may be curious how we breathe and where that oxygen goes once we breathe it. Hopefully by the "end" of their questioning (in reality, the questioning never really ends), the students would have a better understanding of not only the respiratory system in general but also how it relates to their own lives. The following activity (adapted from The Philadelphia Inquirer ) allows the students to create a model of the chest cavity to simulate the way humans breathe.

Objectives for Activity #2:

To build a model of the human chest cavity

To identify some of the major structures of the respiratory system

To explain what role these structures play in enabling humans to breathe

To explain why air is able to enter the lungs

Vocabulary for Activity #2:

trachea

bronchi

lungs

diaphragm

chest cavity

Materials for Activity #2:

for each student:

(1) large clear, soft plastic cup (16 oz. size works well)
(2) flex straws
(2) small balloons
(1) large balloon (9-inch diameter)
paper and pencil to record observations

for class to share:

few pairs of scissors
few rolls of tape (masking, duct, or mailing tape would be best as opposed to scotch tape)

Procedure for Activity #2:

All of these steps can be performed individually except step #4 which may require assistance from a partner. See picture on next page for further illustration of this procedure.

Turn the cup upside down and carefully make a hole in the center of the "top" with the scissors. The hole should be just large enough to f~t two straws in snugly.

Fit the neck of one small balloon over the flex end of each straw. Wrap the tape around the balloon and straw in such a way to prevent any air from escaping.

Stick the two straws up through the hole in the cup so that the balloons are completely contained inside the cup. Place tape over the hole made with the scissors to prevent air from escaping. Bend the straws to form a "Y". Wrap tape around the ends of the two straws that are sticking out of top of the hole. The straws represent the trachea while the entire cup represents the chest cavity.

Next, cut the neck off of the large balloon. Carefully stretch the balloon over the open end of the cup. Hold it in place while a partner wraps tape around it to secure it on the cup. Be sure no air can escape. This balloon represents the diaphragm, the thin muscle between the abdominal and chest cavities.

Press up and down on the large balloon. Watch what happens to the small balloons which represent the lungs. Record what happens in a notebook. Can you explain why this is happening?

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Assessments:

Ask the students to choose any aspect of the respiratory system that they would be interested in researching. They could then present the information they find to the class in any format they choose -- collage, written report, poster, newspaper article etc. Some of the students' research may also lead to a letter to city officials about certain city conditions (for example, air pollution). Some possible topics for the project are "Exercise and Breathing", "The Effect of Smoking on The Respiratory System", "Asthma", "Respiratory Diseases" (e.g. Bronchitis), "The Effects of Air Pollution on the Respiratory System", "Meditation". Another project could be for the students to do a survey of people's pulse rates at different points during the day. The students should also note the people's lifestyles. They could then draw conclusions as to what factors of a person's lifestyle affect their pulse rates (e.g. does that person exercise? smoke? live in the city? Live in the country? etc.)

Ask students to write a story from the point of view of an oxygen molecule as it is breathed in from the atmosphere and travels to our muscle cells.

Extensions:

One interesting project that not only reviews specific skills within this lesson but also incorporates some graphing skills is to have the students create a graph of their pulse rate over the year. They would test it at the same time each day or each week. The students should also note any special circumstances about that day. For example, were they sick? did they recently start exercising? did they only sleep a couple of hours the night before? etc. . . Or the students could all agree to start a daily routine of exercising and see if their pulse rate decreases over the year. Either way, the students would use a graph to understand how certain lifestyle practices affect the pulse rate.

Another experiment related to this one is measuring the students' lung capacities. (See experiment in this booklet.)

"The Egg-citing Egg-speriment" has a good demonstration of diffusion in Warm-Up #1 and Warm-Up #2. Diffusion is how oxygen and carbon dioxide are able to move from the cells to the bloodstream and vice versa.

In addition, this lesson would work well within an entire unit on the human body. Therefore, the students could see how the bodily systems interrelate. In that case, the first assessment given above could be enlarged to include a final project on any aspect of the human body that the students are interested in researching. Spending time on the human body is beneficial because it is something that every student can relate to.

Finally, there are some great CD-ROM's pertaining to the human body. These contain very exciting graphics and interesting facts for the students to explore. Some examples are The Ultimate Human Body by Dorling and Kindersley Multimedia and Body Works 5.0 by Softkey International Inc.

Philadelphia Science Content Standards:

SCIENCE CONTENT STANDARD #1: NATURE OF SCIENCE

Activity #1 of this lesson satisfies Benchmark 1 for grades 5-8 because it allows students to "design, modify, and conduct an investigation through testing, revising, and occasionally discarding ideas, all of which lead to a better understanding of how things work." It also satisfies Benchmark 3 which asks the students to "collect and summarize data from an experiment and interpret the results in terms of the data."

SCIENCE CONTENT STANDARD #4: HUMAN ORGANISM

This lesson covers Benchmark 1 for grades $-8 which states that students should "illustrate how human beings like other animals, have body systems for obtaining and providing energy." Furthermore, Benchmark 2 asks students to "compare and contrast systems for the digestion respiration, and reproduction of various animals." This lesson would satisfy the benchmark partially by exposing students to how the human respiratory system works. Finally, Benchmark 4 states that students should be able to "demonstrate how organs and organ systems work together (e.g., lungs and circulatory system work together to distribute oxygen)." Activity #1 (measuring pulse and breathing rates) satisfies this benchmark.

SCIENCE CONTENT STANDARD #6: BRIDGES TO THE MATHEMATICAL AND TECHNOLOGICAL WORLD

If the CD-ROM's mentioned in the "Extensions" section are used, then students will gain an appreciation for the advances in technology. This would satisfy Benchmark 1 which states that students should "understand that multimedia communication devices are ways to communicate information to others".

SCIENCE CONTENT STANDARD #7: HISTORICAL PERSPECTIVES

If the students chose to do a project on air pollution as part of their assessment, then they would be able to "describe how technology influences our quality of life" (Benchmark 2 for grades 5-8).

Cross-references:

Activity #1 reviews multiplication when the students have to find their pulse and breathing rates. Furthermore, the final assessment project and the "Extensions" section could incorporate a wide-variety of skills depending on what is chosen. Some examples are researching, writing, graphing, and interacting with peers.