LESSON 4: The Circulatory System

LESSON: The Circulatory System

SOURCE: The Incredible Human Body By: Esther Weiner/Scholastic ISBN#: 0-590-59928-3.

HEALTH STANDARDS:

Students will:

comprehend concepts related to health promotion and disease prevention. (1)
demonstrate the ability to access valid health information and health-promoting products and services. (2)
demonstrate the ability to use interpersonal communication skills to enhance health. (5)
demonstrate the ability to use goal-setting and decision-making skills that enhance health.(6)

OBJECTIVES:

Students will:

measure their heart rate and compare it with adults’ heart rates.
calculate the number of heartbeats in one day and if they lived to be 75 years old.
define the circulatory system.
identify the parts of the circulatory system.
construct an informational book on the circulatory system.
observe how exercise changes their pulse and breathing rates.

MATERIALS:

VOCABULARY:

PROCEDURES:

Introduction:

Write these riddles on the board: What travels thousands of miles every day? What muscle never rests and is inside your chest? What system goes ‘round and ‘round your body?
Have the students construct the circulatory system booklet.

Activity 1:

Have students make a fist and place it on their chest slightly to the left. Ask: What muscle pumps all day and night to send blood on a long journey to every section of the body? (the heart) Inform them that their heart is the same size a s their fist.

Ask: What size do you think your heart will be when you become an adult? (adult fist size) To help students get an idea of how hard the heart works, distribute a few tennis balls and have students take turns squeezing one of the balls wi th one had 70 times a minute.

Ask: Where can you feel your heart beat? (On your chest, near your heart; some students may know that you can also feel the heart beat at different pulse points.) Explain that blood travels (circulates) from the heart to all parts of yo ur body through tubes called blood vessels. Blood vessels that carry blood away from your heart are called arteries. Arteries have strong, elastic walls that can stretch so the heart can push or pump blood into them. Usually, arteries are buried deep i n your skin where you cannot see or feel them.

Ask: "Why do arteries need to be deep inside the body?" (This protects them from getting cut.)

Invite the students to look at the underside of their tongue in a mirror. Have them identify the structures they see. Then explain that the thicker pink lines are arteries, the blue lines are veins, and the very red thin lines are smaller blood vessels.

Ask: "Where else can you see blood through your skin? (eyelids, wrists, forearms, back of hands)

Inform students that there are a few places where arteries come near the surface of the skin. Have students guess where these places are. (on the wrist and neck) When students take their pulse, they can feel what happens when the h eart pumps blood into an artery. The artery expands slightly to let the wave of high-pressured blood pass through. Then it returns to normal. This expansion is what we recognize as a pulse.

Invite the students to do the activity on the handout to compare their pulse rates with that of two adults.
Do the first part of this activity/handout in class. Time students as they take their pulses for 15 seconds. This will help them know what to do when they measure the pulse of adults or friends at home.

Activity 2:

Ask students: "Did you know that when you exercise, your heart gets a good workout too? Inform them that athletes’ hearts get so strong that they can push more blood with every beat. That means they can get more oxygen with fewer bea ts per minute. Runners and swimmers can have resting heart rates as low as 35-40 beats a minute.

With a friend timing you, take your resting pulse for 15 seconds and calculate what it is for one minute. Record the results on the chart.
Count the number of times you breathe in for 15 seconds and calculate what it is for one minute. Record your results.
Do jumping jacks for 2 minutes. Now take your pulse and calculate what it is for one minute. Calculate your breathing rate too. Record the numbers.

Conclusion:

Ask the students: "How does your body get more oxygen when you exercise?"" Have them write their answer on their worksheet.
Instruct the students to complete the pulse rate handout at home.
Ask the students to explain why they think adults’ heart rates are higher or lower than theirs are.
Have the students calculate how many times their heart beats in one day. Challenge: how many times would your heart beat if you lived to be 75 years old. Have the students write in their journals how they calculated their answers.

EVALUATION:

Students will be able to define and state the parts of the circulatory system with 100% accuracy.
Students will have a fully constructed circulatory system information booklet. They will place this booklet in their human body folder.
Students will have two handouts completed in their entirety. (Feel the Beat! and A Heart and Lung Exercise) They will place these handouts in their human body folder.
Students will have a journal entry describing how many times their heart will beat in a day and in 75 years. The students will place this entry in their human body folder.
Students will complete a self-evaluation form.