Fourth Grade - Science - Lesson 24 - Circulatory System
 

Objectives

Identify the heart as the strongest muscle in the body.

Calculate how many times a heart beats daily.

Locate pulse and measure heart rate.

Predict how exercise will affect heart rate.

Compile and compare heart rate data from classmates.
 

Materials

Picture of heart from Suggested Books

Picture of the structure of the heart for transparency (attached)

A bell or whistle

Heart rate worksheet (attached)
 

Suggested Books

Cole, Joanna. The Magic School Bus Inside the Human Body. New York: Scholastic, 1989.

Gardner, Robert. Science Projects About the Human Body. Hillside, NJ: Enslow, 1993. This contains several activities concerning pulse and the heart, including how to make a pulse amplifier.

Morgan, Sally. The Human Body. New York: Kingfisher, 1996.

Parker, Steve. Brain Surgery for Beginners and Other Major Operations for Minors. Brookfield, CT: Millbrook, 1995. Page 33 has a good illustration of a heart showing the interior chambers and the veins and arteries leading to it.

Simon, Seymour. The Heart Our Circulatory System. New York: Morrow, 1996. The computer enhanced photos in this book are remarkable. In addition to the photo of the heart itself, the micrographs of red and white blood cells and of single blood cells passing through minute capillaries are truly astounding.
 

Teacher's Note

Prepare a bulletin board or poster entitled Amazing Blood and Guts Facts for posting amazing facts about the heart and circulatory system as well as the respiratory system studied in next month's lessons. Announce an amazing fact by ringing a bell, blowing a whistle or some other fanfare. Have them written out on colored paper for a student to read aloud and then post. Encourage students to discover additional facts.
 

Procedure

Ask: What is the strongest muscle in the body? (Accept all answers.) Tell the students that the strongest muscle in their bodies works every second of the day, seven days a week from the moment they are born and for their whole lives. Tell the students that the heart is the strongest muscle in the body. Ask: Is the heart a voluntary or involuntary muscle? (involuntary because it works whether you want it to or not) Ask: What is the heart's job? (to pump blood through the body)

Ask the students to make a fist. Tell them that their hearts are about as big as their fists. Ask: Where is the heart located? (in the middle of the chest) Show the students a picture of the heart from Suggested Books. The cover picture from The Heart by Seymour Simon is a computer enhanced photo that shows the heart in relation to the lungs. Point out that the heart is tilted a bit to the left. Ask the students to put their hands over their hearts and see if they can feel them pumping. Ask: What bones protect the heart and lungs? (ribs)

Show the students the transparency of the heart. Point out that a real heart is shaped a bit like the heart we see at Valentine's Day. It has two halves, a right half and a left half. Remind them that they have to imagine themselves standing behind the diagram to get the left and right straight. Each half is a pump with tubes for blood going in and out. Point out that each of the pumps has two hollow areas or chambers. The bottom floor is called a ventricle and the top floor is called an atrium. Ask a student to come up and point to the right atrium. Have another student point to the left ventricle. Tell them that the ventricles are the strongest parts of the heart. Ask: How many chambers in the heart? (four) Tell the students that between the atrium and ventricle there are valves that open and close. They can imagine them as trapdoors between the floors.

Tell the students that blood comes from the body into the right atrium and fills it up. When the atrium is filled, the valve opens and blood pours down into the right ventricle. The ventricle squeezes and pumps the blood out to the lungs to pick up oxygen. Meanwhile, blood freshened with oxygen is coming back from the lungs into the left atrium. When it is full, the valve or trapdoor opens and the oxygen-rich blood flows into the left ventricle. The left ventricle is the mightiest chamber of all. The left ventricle squeezes tight and pumps the good blood out of the heart and all over the body, from brain to big toe.

Suggest that the students put another set of muscles to the test to see if they are as strong as the heart. Have the students stand up and divide them into three groups. Tell them that the heart pumps once every second--as long as it takes to say "one-chimpanzee." Have one group try deep-knee bends, one a second. Have another group reach for the sky, once a second and have the third group touch toes, once a second. After a minute, ask: Are your muscles getting tired? Can you imagine leg muscles or arm muscles working this hard 24 hours a day? Ask again: So which muscle is the strongest muscle in the body? (heart)

Ring a bell and announce an Amazing Blood and Guts Fact. On the board, bulletin board or poster described in Teacher's Note, have a student post the fact and read it aloud: The heart is the strongest muscle in the body. Ask: How often does a heart beat? (once a second) Ask: How many times does a heart beat in a day? Do we have enough information to figure it out? (yes) How many seconds are there in a minute? (60) Ask: How many times does a heart beat in a minute? (60) Write 60 times a minute on the board. Ask: How many minutes are there in an hour? (60) Write 60 times x 60 minutes =. Have a student volunteer work the problem on the board or have the students multiply at their seats. Write 3,600 times an hour on the board. Ask: How many hours in a day? (24) Write 3,600 times x 24 hours =. Solve this multiplication problem on the board and write: The heart beats 86,400 times in one day. Ring the amazing facts bell and post this fact.

Tell the students that each time the heart pumps, the stretchy tubes that carry the blood swell a little and then shrink. We call this a pulse. Write this word on the board. Tell the students that there are places where they can feel a pulse. Show the students four pulse points: at the temple, the inside of the elbow, the throat (either side of the adam's apple) and at the wrist. Point out that one must use fingers to feel pulse since the thumb has a pulse, too. Ask the students to find the pulse point at their wrists. If they have trouble feeling it, tell them to slowly move their fingers toward the outside of their wrists until they feel tiny throbs. Each throb is a wave of blood coming from the heart. We also call this heart rate. When the students have found a pulse, tell them you want them to count the number of waves or throbs in 30 seconds. You will keep the time, but they should begin counting silently when you say "go." After 30 seconds say "stop" and have the students write down their pulse counts. Tell them that this is their heart rate while they are sitting.

Divide the class into groups of five and choose a recorder for each group. Give each recorder a group data sheet (attached). Have each recorder go to the members of the group, record his or her name on the group worksheet and fill in the first column under heart rate--sitting for each group member with the number they just counted. When the recorders are finished, ask: Do you think you can make your heart beat faster, your heart rate increase? How? (running, jumping--exercise) Have the students test their theory. Have them hop on one leg 20 times or do arm circles for less than a minute, then immediately count pulse for 30 seconds (you can keep time) and write down the number. Have recorders write after hopping or arm circles at the top of the second column and record results for each member of their groups. Have each group look at their data and answer the questions on the sheet.

Suggest that the students come up with an amazing blood and guts fact for the bulletin board--There are ____ heart beats in our classroom in 30 seconds. Help the students compile the data to fill in the blank, ring the bell and post it on the bulletin board as an amazing fact. Tell the students you have two more amazing facts. (Ring bell and have a student read aloud and post): The heart is so powerful that it takes only a minute for blood to go from the heart all the way around the body and back to the heart. Another amazing heart fact (ring bell): Every day the heart pumps 2,500 gallons--nearly 20 tons--as it recycles blood through a person's body. Point out that the heart is truly the strongest muscle in the body.
 

Possible Homework

Remind the students that they know the number of heart beats in the class in 30 seconds. They also know the number of students in the class plus teacher. Ask: With that information, can they figure out the average heart rate of a student sitting in the class? What is the average heart rate per minute?
 

Fourth Grade - Science - Lesson 24 - Circulatory System
 

Heart Rate Worksheet
 
 
Name of student subject  Heart beats per minute: Sitting
 
 

 


 
 

 


 
 

 


 
 

 


 
 

 

1. Does a person's heart rate change after exercise? How?
 

2. Do you think a person's heart rate would increase or decrease if they went to sleep? What makes you think so?
 

3. Does your data show a difference in the heart rate of boys and girls?
 

Fourth Grade - Science - Lesson 25 - Circulatory System

Objectives
Observe veins and capillaries in wrists and eyes.
Analyze data from an animal heart rate chart.
Observe the color, size and texture of heart tissue (cow's or sheep's heart) and examine its blood vessels (optional).

Materials
Picture of the circulatory system from Suggested Books
Heart transparency from last lesson
Animal heart rate chart for each student (attached)
Cow or sheep's heart (optional) see Teacher Note

Suggested Books
Auraham, Regina. The Circulatory System. New York: Chelsea House, 1989.
Elting, Mary. The Human Body. New York: Macmillan, 1986.
Gardner, Robert. Science Projects About the Human Body. Hillside, NJ: Enslow, 1993. Animal heart rate chart is from this book. It also includes other activities concerning heart rate.
Parker, Steve. Blood. New York: Copper Beech Books, 1997. A brand new and highly-illustrated book about the circulatory system.
_____. Brain Surgery for Beginners and Other Major Operations for Minors. Brookfield, CT: Millbrook, 1995. On page 31 is an illustration of the circulatory system and an illustration of the how blood flows through arteries, to arterioles, to capillaries, then to venioles and to veins.
Royston, Angela. The Human Body and How It Works. New York: Random House, 1990.
_____. What's Inside My Body? New York: Dorling Kindersley, 1991.
Rustean, Jean. The Human Body. New York: Dorling Kindersley, 1993.
Silverstein, Alvin. The Circulatory System. New York: Twenty First Century Books, 1994.

Web site

http://www.sln.fi.edu/biosci/heart

Franklin Institute Science Museum is Philadelphia has a famous giant heart through which visitors can walk. Their web site offers audio of a heartbeat as well as an animated trip down a coronary artery, pictures of blood cells and many links to other heart-related information.

Teacher Note
If you choose to do the optional activity, a cow or sheep's heart can be obtained (with advanced notice) from the meat department of a supermarket. Tell the butcher what you plan to use the heart for so the larger vessels leading into the heart can be preserved. Having an actual heart in the classroom to observe and touch may not be for the squeamish, but the experience can make an enormous difference in the students' awareness of the reality of internal tissues and organs.

Procedure
Remind the students that last lesson they learned amazing facts about the strongest muscle in the body. What is the strongest muscle? (heart) Ask: What does the heart do? (pumps blood through the body) Tell the students that today they are going to follow a road map to see how the blood travels, where it goes and what it does. The road or network of tubes blood travels through is called the circulatory system. Write this on the board. Ask: Why do you think it is called a circulatory system? (because the blood circles from the heart, around the body and then back to the heart)

Show the students pictures of the circulatory system from Suggested Books and point out its pumping station--the heart. Tell them that this is all of the circulatory system the illustrator could show because a lot of it is so tiny that it is invisible. The tubes that blood travels through get so small that only a single blood cell can pass through them. Point out that the picture of the circulatory system looks like a road map with roads branching off every which way into dead ends. Ask: But why can't there be dead ends in the circulatory system? (because it is a circle)

Tell them that the tubes blood travels through are called blood vessels. Ring the bell and tell them that it is time for an amazing-blood-and-guts fact: There are 60,000 miles of blood vessels in the body, enough to stretch more than two times around the Earth. Have a student read aloud and post this fact. Tell the students that if they turn to a neighbor and look closely into the white parts of their neighbors' eyes, they will see very tiny blood vessels that make up an inch or so of their neighbors' 60,000 miles of blood vessels.

Show the students the heart transparency from the last lesson. Tell them that the blood vessels nearest the heart, the ones bringing blood and taking it away, are the biggest and thickest ones. We might call them the blood's main highways. Every time the heart pumps, blood surges through these highways. Ask: Why do you think these are the biggest, thickest blood vessels? (They carry the most blood traffic at a time. The powerful surges from the heart's pump would tear thinner blood vessels.) Point out the aorta and pulmonary arteries that carry blood from the heart to the rest of the body. Tell them that the main highways that carry blood from the heart to the body are called arteries. Write this word on the board. Remind them that the pulse they felt in their wrists was from an artery stretching and swelling to handle the surge or wave of blood coming through it each time the heart pumped. Point out the upper and lower cavae and the pulmonary veins on the transparency. Tell the students that the blood vessels that bring oxygen-poor blood back to the heart are called veins. Write this word on the board.

Again, show the students the picture of the circulatory system from Suggested Books. Ask: What colors did the illustrator use to show the blood vessels? (red and blue) Tell them that red indicates an artery carrying oxygen-rich blood from the heart. Blue indicates a vein carrying oxygen-poor blood from the body back to the heart to be refreshed by the lungs. Ask the students to look at their wrists. Ask: Can you see blood vessels? Can you identify any veins? What makes you think they are veins? (They look blue.)

Tell the students that while arteries and veins are main blood highways, the smaller roads that branch off them are called arterioles and venules. Tell the students that blood travels through arteries and veins and through arterioles and venules, but where blood makes its pick-ups and deliveries is in the tiny, eensy trails and pathways that branch off these arterioles and venules. These are called capillaries. Tell the students that the blood vessels they see in their neighbors' eyes are big capillaries. If available, show the students the photo in The Heart by Seymour Simon taken by an electron scanning microscope of red blood cells passing through the capillaries of an eye's retina. Tell the students that the walls of capillaries are only one cell thick. Through holes in the capillary walls, something in blood leaks out to the surrounding body tissues and something leaks back in to the capillaries. Ask: What do you think leaks out of capillaries; what do you think the oxygen-rich blood is delivering to the body tissues? (oxygen)

Ask: What else do the body's cells need to live? (food) Tell the students that the blood delivers oxygen and nutrition from digested food to the cells in the body. Ask: What do you think leaks into the capillaries; what is the blood picking up that the cells need to get rid of? (waste) Tell the students that the blood picks up carbon dioxide and other wastes that would poison body cells if they were not taken away. So blood travels many miles through the circulatory system to make deliveries and to make pick ups from body tissues. The blood drops off oxygen and food and picks up garbage and takes it away. Ring the bell and announce another amazing-blood-and-guts fact: Over 62 gallons of the liquid part of blood leaks in and out of capillaries in a person's body every minute. Ask a student to read aloud and post the fact.

Ask the students to think about these questions for the next lesson: What exactly is in blood? Why is blood red?

Remind the students about last lesson's homework assignment. Ask: What is the average heart rate of a student in our classroom? Write this figure on the board (It will be between 60 and 100 beats per minute.) Distribute the animal heart rate chart to each student. Ask the students to find the average human heart rate on the chart. Ask: Is this close to our classroom average? How does it compare? If there is a difference, what might explain the difference? (Accept all answers.) Tell the students that the heart rate of young people is usually faster than the heart rate of grown ups. Ask: What is the heart rate of an elephant? Of a mouse? Does the size of a mammal seem to have an effect on its heart rate? (Larger mammals have slower heart rates.) Is the same true of birds? (no) How did you come to that conclusion? (An ostrich's heart rate is faster than that of a sparrow, a smaller animal.) Which animal on the chart has the slowest heart rate? (whale) Compare the heart rates of the bat when it is active and when it is hibernating. What advantage might there be for a hibernating bat to have a much slower heart rate? (conserve energy) What animal on the chart has the fastest heart rate? (hummingbird) How many beats per minute does a hummingbird's heart beat? (1,200 times) Ring the bell to announce another amazing-blood-and-guts fact and post: The hummingbird's heart beats 1,200 times per minute.

Optional Activity
Show the students a cow or calf's heart (see Teacher Note). Have the students identify arteries or veins leading into or away from the heart. If they are not squeamish about touching the heart, ask them to describe the color and texture of heart tissue and the blood vessel tissue. Point out the thickness of the blood vessel walls that must handle the surges of blood through them as the heart pumps. Have them look or carefully feel inside the blood vessels for valves. Ask: How does the size of a cow's heart compare with the size of a human heart? How do cows and humans compare in body size? If students touch the heart, be sure to have them wash their hands.

Fourth Grade - Science - Lesson 25 - Circulatory System
 
 



Animal Heart Rates

ANIMAL HEART RATE* ANIMAL HEART RATE*
MAMMALS
mouse 376
bat 660 seal 80
bat (hibernating) 30 shrew 800
camel 28 white rat 300
cat 200
BIRDS
cow 50 crow 380
elephant 30 hummingbird 1200
giraffe 66 mallard 320
goat 81 ostrich 65
grey whale 9 robin 570
hedgehog 250 sparrow 50
human 70 starling 390
lion 40 turkey 93

 

Table 1: The heart rates of various animals.
 

*Heart rate of animal at rest (beats per minute)
 

Fourth Grade - Science - Lesson 26 - Circulatory System

Objectives
Describe what blood does as it travels through the body.
Identify the ingredients in blood and describe the job of each.

Materials
Apron or chef's hat
Large glass or clear plastic bowl, mixing spoon
One pitcher of water, colored pale yellow with food coloring
One pitcher of water colored red
Cup of water colored orange
One teaspoon of milk
1/4 cup measure and a teaspoon
Pictures of red blood cells, white blood cells and platelets from Suggested Books

Suggested Books
Burgess, Jan. The Heart and Blood. Englewood Cliffs, NJ: Silver Burdett, 1988.
Cole, Joanna. The Magic School Bus Inside the Human Body. New York: Scholastic, 1989. There are plenty pictures of red blood cells in this book but the white blood cells look more like fried eggs than the spiky balls they resemble in electron microscopy.
Parker, Steve. Brain Surgery for Beginners and Other Major Operations for Minors. Brookfield, CT: Millbrook, 1995. Page 33 has a good illustration of a heart.
Simon, Seymour. The Heart Our Circulatory System. New York: Morrow, 1996. Contains excellent scanning electronic micrographs of red and white blood cells and platelets.
Stein. Sara. The Body Book. New York: Workman, 1992.
Ward, Brian. The Heart and Blood. New York: Franklin Watts, 1982.
Zim, Herbert. Blood. New York: Morrow, 1968. In addition to a section on blood-eating animals with pictures of each, there is a good section on how, in the development from sea dwelling to land dwelling creatures, sea water has evolved into blood.

Procedure
Ask: Why do you need blood? Why do you need it to move through your body? (Blood delivers oxygen and food to the body's tissues and picks up waste.) Remind the students of the questions you asked them to think about last lesson: What exactly is in blood? Why is blood red?

Tell the students that before you tackle those questions you would like them to brainstorm and come up with a list of blood-eating animals. The list might include: vampire bat, mosquito, tick, flea, leech, horse fly...and human. Explain that some people like to eat blood sausage and blood puddings. Put on the apron or chef's hat and tell the students that for today's lesson you have transformed yourself. You are no longer (your name) but are now (ring the bell) Julia Wild, star of the most popular cooking show on the Mosquito Coast--the show every mosquito loves--Julia Wild's Mosquito Kitchen! Say: Today I will need members of the studio audience to help me with a very special recipe, one handed down to me from by grandmother. Do I have any volunteers from the studio audience? When the volunteers come forward, tell them that they will be helping you make Blood Soup. Tell them that to make blood soup, one must start with an essential ingredient called plasma. Write on the board: Recipe for Blood Soup and underneath that one pitcher of plasma. Tell the students that plasma is mostly water with small amounts of salt and other minerals such as calcium. Have a volunteer describe what plasma looks like (pale yellow) and pour it into the mixing bowl. Tell the students that plasma is like the stock of the soup. It is the liquid part of blood in which other ingredients float. It carries nutrients from digested food and leaks out of capillaries to feed a body's tissues. Plasma also has antibodies in it that fight contagious diseases.

Tell the students that the second ingredient in blood soup is what makes blood look red--red blood cells. Tell them that because red blood cells are so tiny, you have a blow-up picture to share with the audience. Show the students a picture of red blood cells from Suggested Books. (Seymour Simon's book contains a scanning electron micrograph of red blood cells traveling through a blood vessel.) Ask: What shape are red blood cells? (round, flat like a doughnut or bagel with no hole in it) Tell the students that there are more than 25 trillion red blood cells in a human body, more red blood cells than there are stars in our galaxy. Ring the bell to announce another amazing-blood-and-guts fact. Have a student post it. Tell them that red blood cells have a secret ingredient that makes them red. It is called hemoglobin. Write this word on the board. Tell them that hemoglobin is the part of the red blood cells that carries oxygen to the body's tissues and carries carbon dioxide back to the lungs so humans can breathe it out. Write one pitcher of red blood cells including hemoglobin on the board. Have a volunteer pour the red blood cells into the bowl and mix.

Say: Ah! I must tell all you mosquitoes at home--this is looking good! But there is still something missing--something very important. Write on the board 1 teaspoon white blood cells. Tell the students that these cells are bigger than red blood cells but still very tiny. Show the students a picture of white blood cells from Suggested Books. Ask: What shape are white blood cells? (round, fuzzy-looking balls or blobs) Tell the students that white blood cells have a special job in the blood. They attack invaders such as germs and destroy them. White blood cells are like a special forces team that fights disease. Have a student measure out 1 teaspoon of milk and pour it into the bowl. Tell the students that there is one other ingredient that some cooks leave out but blood soup would not be blood soup without it. Write on the board: 1/4 cup platelets. Show the students a picture of platelets from Suggested Books. Tell the students that platelets are what makes blood clot when a human gets a cut. Platelets rush to the cut and glue themselves together to clog up the leak. Have a volunteer pour in the platelets (orange water) and mix.

Say: Now Julia Wild has a challenge for the studio audience to see if they have been on their toes. Name an ingredient in blood and tell me what it does. (plasma-carries food to body's tissues, red blood cells-contain hemoglobin that makes blood red and carries oxygen to the body's tissues and takes away carbon dioxide for the lungs to breathe out, white blood cells-fight disease, platelets-clot the blood when there is a cut) When all four ingredients are named and their jobs described, say: We hope you mosquitoes in the studio audience and at home have enjoyed cooking with me today. This is your host, Julia Wild, saying good-bye and remember: keep buzzing and watch out for swatters.

Possible Homework
Ask the students to think about how the word heart is used in our everyday language. Have them make a list of words or phrases with heart in them such as heartbreak, heartless, heart-to-heart talk, take it to heart as well as names of books, movies, songs and T.V. shows with heart as part of their titles.
 

Fourth Grade - Science - Lesson 27 - Circulatory System

Objectives
Review where in the body blood cells are manufactured and observe bone marrow.
Compare information on food labels to determine which products are most healthy for heart and blood.
Create a menu and advertising for a Healthy Heart Breakfast Cafe.

Materials
Beef bone with marrow
Food Pyramid/Healthy Heart Tips handout (attached)
For groups of five students: empty cereal boxes, fruit juice cans, milk cartons, frozen waffle boxes, bread wrappers, canned fruit cans and other food labels, paper and crayons or colored pencils

Suggested Books
Burgess, Jan. The Heart and Blood. Englewood Cliffs, NJ: Silver Burdett, 1988. Contains a section on diet and exercise for a healthy heart.
Parker, Steve. Blood. New York: Copper Beech Books, 1997.
Showers, Paul. Hear Your Heart. New York: HarperTrophy, 1987. A Let's-Read-and-Find-Out Science book with tips on how to stay healthy.
Stein. Sara. The Body Book. New York: Workman, 1992. Although for middle schoolers, this book includes an easy-to-understand and well-written explanation of the liver's function.

Procedure
Ask: What gives blood its color? (red blood cells) Remind the students that red blood cells contain hemoglobin. Ask: What does hemoglobin do? (carries oxygen to the body's tissues and picks up carbon dioxide to take away) Tell the students that red blood cells live about four months before they die and have to be replaced. Remind the students that in studying bones and the skeletal system in third grade, they learned where red blood cells are made. Ask: Does anyone remember where in the body red blood cells are manufactured? (inside large bones in the bone marrow) Show the students a beef bone and the spongy interior marrow where blood cells are made. Ring the bell to announce an amazing-blood-and-guts fact: Every second the human body makes 8 million red blood cells in bone marrow. Have a student read and post the fact. Tell the students that white blood cells and platelets are also made in the bone marrow.

Tell the students that while 8 million red blood cells are produced every second, another 8 million a second die. Ask: What do you think happens to all those red blood cells after they die? Where do the dead cells go? (Accept all answers.) Tell the students that dead blood cells and the waste from the other body cells float in the blood. Ask: What might happen if all the cells dying each second and all the wastes flowing back into the capillaries built up in the blood? (They might poison the body.) Tell the students that the body has a special recycling center for blood. It is called the liver. Show the students a picture of the position of the liver in the body from Suggested Books. Tell them that blood flows into the liver to be cleaned up. The liver breaks down dead cells and reuses their parts to make other things the body needs. What cannot be recycled, such as the red color in red blood cells, is disposed of in the intestines.

Show the students a picture of the circulatory system from Suggested Books and review with them the pathway blood takes as it circulates through the body: heart--to lungs--to heart again--pumped through arteries--to smaller arterioles--to even smaller capillaries--to venioles--flows into veins--back to heart and lungs. Tell the students that at one time people did not know much about the heart's job. They did not know that the heart was a pump or that blood circled the body. The first person to write down this idea was an Arab doctor named Al-Nafis who lived in the 13th century. Not many people came to know of his idea though. Nearly three centuries later, in the 1600s, an English doctor named William Harvey worked out the idea on his own and published his findings. Many of the doctors of the time disagreed with Dr. Harvey's idea. They thought arteries were filled with air and questioned how blood and air could fill the same space. Dr. Harvey's career was almost ruined. A few years later the newly-invented microscope was used to investigate his idea. With microscopes people could see blood flowing through the the capillaries in the tail of a live fish. After that, doctors believed Dr. Harvey's idea of circulation and he became the doctor to the King of England.

Tell the students that today doctors know a lot more about the heart and blood and the circulatory system. They know there are things we can do to keep our hearts and circulatory systems healthy. Write exercise on the board. Ask: Why do you think exercise would be important for a healthy heart? What happens to your heart rate when you exercise? (Exercising makes the heart beat faster. Because the heart is a muscle, working out makes it stronger.) Write healthy heart foods on the board. Tell the students that doctors and nutrition experts say that to have a healthy heart you need to eat a variety of foods from all the food groups. Distribute the food pyramid and healthy heart tips. Ask: What are the food groups in the food pyramid? (breads, cereal rice and pasta; vegetables; fruits; milk, yogurt, cheese; meat, poultry, fish, beans, eggs and nuts; at the top of the pyramid--fats, oils, sweets) Point out that eating foods with iron and vitamin C is one of the Eating for a Healthy Heart tips. Tell the students that iron is what lets hemoglobin in the blood hold on to oxygen. Vitamin C helps the body get iron from foods. Point out that a diet high in fat is bad news for the heart. Ask the students to name some foods high in fat (bacon, french fries, cheeseburgers, whole milk, fried chicken). Tell the students that a diet high in fat can cause something called plaque to build up on the inside of blood vessels. Ask: What do you think might happen to the heart if arteries got clogged up with plaque? (Blood and oxygen could not get through. Without oxygen the heart cells would die.) Tell the students that when oxygen-rich blood cannot get to the heart, a person has a heart attack. Blockages in the arteries in other places causes strokes.

Divide the students into groups of five and distribute food containers and labels. Ask them to imagine that they are restaurateurs (restaurant owners) who are opening up a new restaurant called The Healthy Heart Breakfast Cafe. Suggest they consult Healthy Heart Tips sheet, food pyramid and food labels to create a breakfast menu for the new restaurant. Also ask them to create a poster, sign, newspaper ad or jingle to advertise their restaurant and persuade people to come in for breakfast.

Possible Speaker
Invite a cardiologist, internist or other health professional to discuss prevention of heart disease.
 

Fourth Grade - Science - Lesson 27 - Circulatory System

Alphabet of Low-Fat Foods

Apple, apple juice
Asparagus
Banana
Beans
Beets
Broccoli
Cabbage
Cauliflower
Cherries
Chickpeas
Cocoa made with skim milk
Collard greens
Corn
Crab
Cranberries
Cucumbers
Dates
Egg whites
Figs
Greens
Grapefruit
Lettuce
Mango
Melon
Milk, skim
Mushrooms
Noodles
Oatmeal
Onion
Orange, orange juice
Peach
Pear
Plum
Raisins
Rice
Spaghetti
Squash
Sweet Potato
Tomato
Tuna
Turkey
Turnip
Wheat cereal
 

Fourth Grade - Science - Lesson 28 - Dr. Charles Drew
 

Objective

Write a letter to the Medical Hall of Fame explaining why Dr. Charles Drew should be inducted.
 

Materials

Photo of Dr. Charles Drew from Suggested Books
 

Suggested Books

Altman, Susan. Extraordinary Black Americans. Chicago: Children's Press, 1989. Highlights Drew's research into plasma and standardization of blood collection and processing for the Blood for Britain project. Includes a good photo of Dr. Drew.

Green, Richard ed. A Salute to Black Scientists and Inventors. Chicago: Empak Publishing, 1993. The page on Dr. Drew in this booklet can be read to the class if the lines concerning discrimination at the hospital after his accident are eliminated. This statement has been proven to be erroneous.

Jackson, Garnet. Charles Drew, Doctor. Chicago: Modern Curriculum, 1994.

Peters, Margaret. The Ebony Book of Black Achievement. Chicago: Johnson Publishing, 1974. While this book perpetrates the myth that Drew bled to death after being refused admittance to a white hospital, the description of Drew's leadership in the plasma project is accurate.

Shapiro, Miles. Charles Drew: Founder of the Blood Bank. Austin, TX: Steck-Vaughn, 1996.

Yount, Lisa. Black Scientists. New York: Facts on File, 1991. Contains a thoughtful and highly readable account of Drew's life with photographs.
 

Teacher Note

As noted in the Suggested Books, some sources contain misinformation concerning the circumstances of Dr. Drew's death.
 

Procedure

Tell the students that an important life-saving discovery scientists have made is how to replace a person's blood if he or she is badly injured. Providing a person with blood from another person is called a transfusion. Write this word on the board and point out that trans means across and fusion means combine. Tell them that when transfusions were first tried, they were not usually successful. The patients often died. That was because scientists did not know that all blood was not the same. Then in 1900 a doctor named Karl Landsteiner in Austria looked closely at many blood samples. He found a certain molecule on the surfaces of all the red blood cells in some samples. He called the molecule Molecule A. Blood with that molecule he called Type A blood. Other blood samples had another special molecule on the surface of the red blood cells which he called Molecule B. Blood with that molecule he called Type B blood. Samples with both molecules he called Type AB. Samples that had no special molecules at all he called Type O blood. Write Type A, Type B, Type AB and Type O on the board. Tell the students that these are the four main types of blood. Landsteiner found that if he mixed Type A and Type B blood together, the blood cells clumped up and clotted. This was why the transfusions were not working. Landsteiner showed that the blood type of the person giving blood and the blood type of the person receiving it had to be compatible. He received a Nobel Prize for his work.

Tell the students that a problem with blood transfusions used to be that blood could not be stored for very long before it went bad. If there was not a fresh supply of a patient's blood type or a blood donor with a matching blood type standing by in an emergency, the patient was not able to have a transfusion and would die. Show the students a photo of Charles Drew from Suggested Books. Read an account of his life to the class or tell them that this African-American doctor and surgeon, Dr. Charles Richard Drew, decided to tackle the problem of how to make blood for transfusions available to the largest number of people. He studied the chemistry of fresh blood and how it changed over time. With a colleague, he opened a blood collection center--a blood bank--at the hospital where he worked and learned how to preserve blood as long as possible. Other doctors had suggested that blood plasma would stay fresh longer than whole blood. Ask: Can plasma without red blood cells in it carry oxygen? (no) A plasma transfusion cannot provide oxygen-carrying blood, but it can keep the blood vessels filled with fluid and keep the patient from dying of shock. Dr. Drew studied this idea and found it was true. The plasma could be separated from the rest of the blood and then dried into a powder for later use. Tell the students that there was an urgent reason for Dr. Drew's research into blood supplies during this time. World War II had broken out and German planes were bombing Britain. There were many, many injured people there and a very small blood supply for transfusions. Dr. Drew was asked to head up the Blood for Britain program--to collect, process and ship blood plasma to Britain to care for the wounded. It was an enormous job, one that required not only a blood expert but also a leader who could organize people. Dr. Drew quickly set up safe procedures for collecting blood and removing plasma from it at blood centers around the country. He also opened a central laboratory to test the quality of the plasma before it was shipped to Britain. Seventeen thousand pints of plasma were shipped to Britain and used to save lives until the British could set up their own blood bank.

When it looked like the U.S. would enter the war, the army asked Dr. Drew and the American Red Cross to set up a national blood bank for American soldiers who would be fighting in the war because they would need huge amounts of blood plasma. Dr. Drew took on this even bigger job and in a very short time organized the American Red Cross national blood collection program. In 1941, the Red Cross made a policy to keep the blood from white people and black people separate. Dr. Drew could not live with this policy. He resigned his job. He called a press conference and told reporters, "The blood of individual human beings may differ by groupings [types], but there is absolutely no scientific basis to indicate any difference according to race." Dr. Drew became a teaching doctor at Howard University and taught many young black surgeons. The blood bank he organized for the American Red Cross became a model for the present-day Red Cross's volunteer blood donation program. Thanks to Dr. Drew, millions of lives have been saved.

Have the students write a letter to the Medical Hall of Fame explaining why Dr. Charles Richard Drew should be inducted.

Possible Speaker

Invite a representative from the American Red Cross to speak to the class about their blood donor program and how blood is processed and preserved.
 
 



Bibliography


 










Reference
Allison, Linda. Blood and Guts: A Working Guide to Your Own Insides. Boston: Little Brown, 1995. (0-316-03443-6)
Altman, Susan. Extraordinary Black Americans. Chicago: Children's Press, 1989. (0-516-00581-2)
Auraham, Regina. The Circulatory System. New York: Chelsea House, 1989. (0-791-00013-3)
Burgess, Jan. The Heart and Blood. Englewood Cliffs, NJ: Silver Burdett, 1988. (0-382-09700-9)
Cole, Joanna. The Magic School Bus Inside the Human Body. New York: Scholastic, 1989. (0-590-41427-5)
Elting, Mary. The Human Body. New York: Macmillan, 1986. (0-020-43080-9)
Gardner, Robert. Science Projects About the Human Body. Hillside, NJ: Enslow, 1993. (0-894-90443-4)
Jackson, Garnet. Charles Drew, Doctor. Chicago: Modern Curriculum, 1994. (0-813-65238-3)
Markle, Sandra. Outside and Inside You. New York: Bradbury, 1991. (0-027-62311-4)
Morgan, Sally. The Human Body. New York: Kingfisher, 1996. (0-753-45031-3)
Parker, Steve. Brain Surgery for Beginners and Other Major Operations for Minors. Brookfield, CT: Millbrook, 1995. (1-562-94604-8)
________. Blood. New York: Copper Beech Books, 1997. (0-761-30611-0)
Peters, Margaret. The Ebony Book of Black Achievement. Chicago: Johnson Publishing, 1974. (0-874-85040-1)
Royston, Angela. The Human Body and How It Works. New York: Random House, 1990. (0-679-80860-4)
________. What's Inside My Body? New York: Dorling Kindersley, 1991. (1-879431-07-6)
Rustean, Jean. The Human Body. New York: Dorling Kindersley, 1993. (1-564-58249-3) Shapiro, Miles. Charles Drew: Founder of the Blood Bank. Austin, TX: Steck-Vaughn, 1996. (0-817-24403-4)
Showers, Paul. A Drop of Blood. New York: Scholastic, 1989. (0-064-45090-2)
________. Hear Your Heart. New York: HarperTrophy, 1987. (0-064-45007-4)
Silverstein, Alvin. The Circulatory System. New York: Twenty-First Century Books, 1994. (0-805-02833-1)
*Simon, Seymour. The Heart: Our Circulatory System. New York: Morrow, 1996. (0-688-11408-3)
Stein. Sara. The Body Book. New York: Workman, 1992. (0-894-80805-2)
Ward, Brian. The Heart and Blood. New York: Franklin Watts, 1982. (0-531-04357-6)
Yount, Lisa. Black Scientists. New York: Facts on File, 1991. (0-816-02549-5)
Zim, Herbert. Blood. New York: Morrow, 1968.

* Required or highly recommended