Lesson 3 of 3 Grade Level: 5-8 Subject: Science, Mathematics Prep Time: 10 20 minutes Activity Duration: One class period (50 minutes) Materials Category: General Classroom Science 4a National Education Standards Mathematics 3b Technology ISTE ITEA Geography Objective: Recording and analyzing data, using the scientific method to investigate a problem, and multiplying whole numbers. Materials: Watch or clock with a second hand Pillows and a chair to create an inclined plane Data sheet Calculator (optional) Related Links: NASA Site used for the derivation of Lesson Plan The Orbitson s Upside-Down Jumping Jacks http://k12unix.larc.nasa.gov/mars/zone3/jumpingjacks.html
Teacher Sheets Pre-Lesson Instructions Using a calculator is optional. If whole number multiplication is a skill that students need to practice do not let them use calculators. Explanation of a hypothesis might be necessary. Background Information Activity 1 Cardiac output is the amount of blood (in milliliters) pumped by the heart in one minute. Cardiac output helps determine the health of the heart and cardiovascular system. On Earth and in space, different conditions can change cardiac output. If a person is exercising, the body requires more oxygen to fuel the muscles. Therefore, the heart pumps harder, so that the blood flow to the muscles can increase and the needed oxygen can be provided more quickly by the blood. Cardiac output is the product of the stroke volume and the heart rate. Cardiac output = stroke volume x heart rate (ml/min) = (ml/beat) x (beats/min) Stroke volume is the amount of blood pushed through the heart during each heartbeat. It is measured in milliliters per beat, and normally remains at about 75 ml/beat. Heart rate defines how fast the heart is beating. It is measured by taking one's pulse, and is measured in beats per minute. Activity 2 The heart, lungs, and blood vessels function differently in space than they do on Earth. All astronauts experience a headward shift of body fluids known as the "Puffy-Head, Bird-Legs" syndrome. In zero gravity the blood and other body fluids move from the feet, legs, and lower trunk to the upper body and the head (toward the central circulation around the heart). This results in a feeling of fullness and puffiness in the face, and legs that look skinnier. To simulate this fluid shift, a student's body will need to be in a head-down tilt position. In this position, the stroke volume increases from about 75 ml/beat to about 90 ml/beat. This is due to a rush of fluids to the upper part of the body and then the heart has more
blood to force out with each beat. To compensate for this increase in stroke volume (to keep cardiac output relatively stable), the subject's heart rate decreases. When students do this experiment, they will probably have lower heart rates, however they need to use 90 ml/beat for the stroke value in determining cardiac output. In the head-down tilt position, the student's head should be below the horizontal and their legs should be above the horizontal. One way to create this situation is to bring pillows to the classroom. Have a student lie down on them with his legs pointing upward supported by a chair. (Make sure they dress appropriately!) Place only one pillow under the head and 3 or 4 pillows under the back. Depending on your resources you could also use a board tilted at an angle or a weight bench. (Student's could also do this standing on their heads, but make sure you use appropriate safety precautions.) Guidelines 1. Read and discuss the article. 2. Go over procedure. If needed give students time to learn how to find and count their own pulse. 3. Have all the students complete activity 1 and stop. Discuss activity 1 (make sure to include background material from above in discussion). 4. Have all students complete activity 2. Again make sure to include background information from above in preparation and discussion of activity 2. 5. Clean up and discuss the overall experiment. Discussion / Wrap-up 1. Discuss again why in the first activity the stroke volume was 75 ml/stroke and in the second activity the stroke volume was 90 ml/stroke. Extensions Lesson two from this article relates heart rate to exercise and body movement
Student Sheets Objective Recording and analyzing data, using the scientific method to investigate a problem, and multiplying whole numbers. Materials Watch or clock with a second hand Pillows and a chair to create an inclined plane Data sheet Procedure Follow all directions on the next sheets as well as following all instructions from your teacher. A hypothesis is your prediction of what will happen when you conduct an experiment that is intended to answer a question. Before each activity you will be asked to write your hypothesis. Remember that this is an educated prediction and does not have to be the correct response. Simply explain your answer to the question. Cardiac Output is how much blood your body pumps in one minute. Think about when your body might need to have more blood flowing (remember blood carries oxygen to your brain and muscles). Your body uses oxygen for movement and for other biological functions (digestion, etc.) as well.
Worksheet Name: Problem 1: How are cardiac output and exercise related? Hypothesis: 1.Sitting in a chair, take your resting heart rate. (Take pulse for 10 seconds, then multiply by 6.) 2.Record resting heart rate in data chart. 3.Calculate resting cardiac output by multiplying stroke volume times heart rate. Use 75 ml/beat for stroke volume. (Cardiac output = stroke volume x heart rate) 4.Record resting cardiac output. 5.Stand and do 25 jumping jacks. 6.Take your heart rate immediately after exercise. Record data. 7.Calculate your cardiac output after exercise. Record data. 10 Second Pulse Count Heart Rate (beats/min) Stroke Volume (ml/beat) Cardiac Output (ml/min) Sitting x 6 = x 75 = Exercise x 6 = x 75 = Conclusions: 1.What happened to your heart rate immediately after exercising? Why do you think this happened? 2.What happens to cardiac output after exercising? Why?
Problem 2: How does being in space affect cardiac output during periods of exercise? Hypothesis: 1.Lying in a head-down tilt position, take your resting heart rate. Record data. 2.Calculate resting cardiac output by multiplying stroke volume times heart rate. Use 90 ml/beat for stroke volume. (Cardiac output = stroke volume x heart rate) 3.Record resting cardiac output. 4.Still in the head-down tilt, do 25 jumping jacks. 5.Take your heart rate immediately after exercising. Record data. 6.Calculate your cardiac output after exercise. Record data. 10 Second Pulse Count Heart Rate (beats/min) Stroke Volume (ml/beat) Cardiac Output (ml/min) Head-down x 6 = x 90 = Head-down Exercise x 6 = x 90 = Conclusions: 1.How is your exercising heart rate when you were standing different from your exercising heart rate in the head-down tilt position? 2.How is your exercising cardiac output when you were standing different from you exercising cardiac output in the head-down tilt position? 3.Describe how your head and body felt while you were in the head-down tilt position.