Content Area: Life Science. Process Skills: Observing - look and feel the heart; Classifying - the heart belongs to circulatory system; Interpreting data - graph the average rate and determine where they place on the graph.
Instruct students to lay their hand (palm side up) on their desk and have students count how many times they can open and close their hand for one minute. Their hands should start getting tired after about 45 seconds. The students might start to wonder what they are doing... be sure they record how many times they opened and closed their hand. Don't stop! Let's see if we can keep going a little longer. Ask students what is their hand doing? (opening and closing). What part of the body might your hand represent? Which system of the body might use the heart?
- "The Beat Goes On" worksheet (see bottom of file)
- Seconds timer (stopwatch)
- Beef hearts cut in two
- Diagram of the heart from science textbook
- Dish pan for each heart
- Sharp knife to cut hearts in two
To find pulse rate:
Place index and middle fingers on your wrist or neck. (Do not use your thumb). Hold fingers in place until you feel the steady beating of your pulse. When the teacher says 'go,' have students count the beats for six seconds. Multiply this count by 10 to find the number of beats per second.
First, the students should take their resting pulse rate. Then have them jog in place for one minute and take another pulse rate to compare the resting pulse rate and the active pulse rate.
Divide class into cooperative groups of four by numbering off 1-4. Now, assign all roles to a number. 1 - Starters, 2 - Getters, 3 - Readers, 4 - Recorders.
Get several animal hearts from a butcher and wash them before students handle them. Cut each heart in half lengthwise, exposing as many chambers as possible. Getters will come to supply table and get one heart for their group. The Starters will point to the part of the heart the teacher is identifying and make sure that everyone sees it. The Readers will point out on the diagram which part the teacher is identifying. They will be able to observe the heart chambers, the difference between the upper and lower chambers, the openings through which blood had flowed, the muscular composition of the heart and blood vessels on the exterior of the heart. The students will identify the chambers using the diagram and the functions of each chamber. The Recorder will record the observations made by the group.
The teacher writes observation questions on the blackboard:
- What did you see inside the heart? (Different chambers and muscles)
- How did the heart feel when you touched it? (Smooth and rubbery)
- How do the different regions of the heart compare? (More muscle around the lower chambers)
The students will compare their heart rates and use the beef heart to show the route the blood flows through the heart. They will average the heart rates among their group.
Introduce lesson with hand activity and focusing questions.
Find the resting and active pulse rate.
Divide the class into cooperative groups and assign roles.
Go over safety rules.
Safety Rules: No sharp items left out during exploration. Make sure all students wash their hands immediately after exploration. Check with students about feelings toward handling the heart. If someone does not want to touch it, they can just observe. Wash hearts prior to handling.
- Listen to all instructions.
- Walk to and from supply table.
- The heart stays on the table at all times.
- Wash hands immediately after experiment, & use soap and water.
- Share with everyone in your group.
- If an accident occurs, one student will be directed togo for the nurse, if needed.
- Getters will go to the supply table and get a heart for their group. The Starters will point to the part of the heart the teacher identifies. The Reader points to the part on the diagram.
- The teacher writes observation questions on the blackboard while the students are exploring the heart.
- The Recorders record the observations of the group.
- The Getters return the heart to the supply table.
- Everyone washes their hands using soap and water. The group compares heart rate with other members of their group. They discuss the flow of the blood through the heart. The teacher then disposes of the hearts in a plastic bag and closes it. The Recorder makes sure everyones name is on the observation paper and turns it into the teacher. The teacher asks what they have discovered and leads into explanation. Graph the average resting and active heart rates on the board.
- What did you find out?
- How many hearts do we have?
- Do you think the heart plays an important role in the circulatory system? Why?
- Does everyone agree?
- What are some things we can do to make sure we keep our hearts healthy? (Exercise and diet.)
Graph the average heart rates of each group on the board.
Calculate the average for the class. Let students determine where they fall in comparison to the average. List similarities of the beef heart to the human heart.
Each student will record for one week what they eat and the exercises they do in their journal.
At school, they will determine if they are doing what it takes to keep their heart healthy. They will write an agreement from their self to their heart to be more aware of their habits and write down some changes or modifications they want to make.
The students worked cooperatively in their groups and were actively involved. The students participated in discussion. The group observation report was turned in.
- Circulatory system
- The group of organs that carries nutrients, oxygen, and other substances to all cells of the body.
- Heart rate
- the rate at which the heart pumps blood through the heart.
- Upper right chamber
- collects blood from the body.
- Lower right chamber
- Pumps blood to the lungs.
- Upper left chamber
- receives blood form the lungs.
- Lower right chamber
- pushes blood to the rest of the body.
Teacher Content Background
The Heart - The two halves of the heart are separated by a membrane called the septum. This wall prevents the flow of blood between the two atria or the two ventricles.
The heart pumps blood in two phases. In the systolic phase, the ventricles contract, pumping blood into the arteries. In the diastolic phase, or second phase, the ventricles relax and blood flows into them from the atria. These two phases of the heartbeat are measured when the blood pressure is taken.
The valves within the heart are one-way valves. This means that blood can flow into the heart but not back into the arteries or ventricles.
The heart is a hollow muscle. It is about the size of your fist. It is located slightly to the left of the center of your chest. The hollow inside is divided into four sections. These sections are called chambers. Two chambers are on the left and right side. Each side has an upper and lower chamber. The right upper receives blood from the body. The right lower pumps blood to the lungs. The left upper receives blood from the lungs. The left lower pumps blood to the rest of the body.
Integration with Other Subject Areas:
- Math - Students will calculate how many times your heart beats per minute. Hour? Day? Year?
- Health - Students will keep a record of heart rate for a period of two weeks to find their average. They will also create a healthy diet plan.
- History - Students will research the first heart transplant.
- Language Arts - Students will write a letter to their heart and tell what they will do to keep it healthy.
- Art - Students will create a poster with a message relating to the heart.
The Beat Goes On Worksheet
My Resting Heart Rate
(when I'm calm and relaxed)
_______ beats in 6 seconds x 10 = ______ beats per minute
My Active Heart Rate
(after I've jogged in place for 1 minute)
______ beats in 6 seconds x 10 = ______ beats per minute