NameSunday, March 10

Date

Circulatory SystemBy Sharon Fabian

Blood circulates through your body all the time through a complicated system of large and small pathways. Yourheart pumps day and night to transport the blood on its nonstop journey. This is your circulatory system, and it is inconstant motion for a very good reason. Your circulatory system is like the freight train that delivers essentialsupplies to wherever they are needed in your body.

As blood travels to all parts of your body, it delivers food and oxygen to your cells. It removes carbon dioxide andother waste materials. Along the way, it also helps to regulate your body temperature.

The center of your circulatory system is your heart. It is a hollow muscle with two side-by-side pumps. When youare resting, your heart pumps about 70 times each minute. When you are exercising, it pumps even more. Thepump on the right side sends a supply of blood to your lungs. The pump on the left side sends blood to all otherparts of your body.

Another part of the system is blood vessels, the rubbery tubes that carry the blood from place to place. The threetypes of blood vessels are arteries, veins, and capillaries. Arteries carry blood from the heart; the main one is theaorta. Veins carry blood to the heart; the two main ones are called the vena cava. Capillaries are very tiny bloodvessels that connect arteries to veins.

The third part of the circulatory system is the blood itself. Blood is made up of a liquid called plasma and threetypes of particles called red cells, white cells, and platelets. An average sized adult has about 5 quarts of blood inhis body. A child who weighs 80 pounds has about 2 1/2 quarts of blood.

The circulatory system does its job by working together with other body systems. It works with your respiratorysystem to deliver oxygen. After your lungs take in a good breath of air, the oxygen passes into your blood stream.The blood travels to your heart, where it is pumped out the left side, through your aorta, to all parts of your body.Blood carries its supply of oxygen through your arteries, then through smaller capillaries, and finally delivers itthrough the capillary walls to wherever it is needed. Next, carbon dioxide, which you don't need, comes into thecapillaries, passing right through the capillary walls just like the oxygen did. It flows through little capillaries, thenthrough larger veins back to the heart through a main vein, the vena cava. The right side of your heart pumps thissupply of blood, with its cargo of carbon dioxide, to your lungs, and you breathe out. One journey is finished!

Your circulatory system works with your digestive system in much the same way that it works with yourrespiratory system. It carries digested food to everywhere it is needed. Food enters the blood stream the same waythat oxygen does, right through the wall! Digested food passes through the wall from your small intestine into yourcapillaries. Your blood stream carries it on a complete path through your body, with a stopover at your liver. Itdelivers the nutrients, the good parts of the food, to the right places, and carries the waste products on to otherplaces so they can be disposed of.

Blood helps regulate your temperature too. When the weather is hot, lots of blood flows to your skin where it canrelease heat from inside your body. In cold weather, less blood flows to your skin, to keep more of your heatinside.

Your heart, blood vessels, and blood make up a system that can do all kinds of useful things! In fact, they make upthe best transportation system ever invented -- your circulatory system.

NameSunday, March 10

Date

Circulatory System

Questions

1. The circulatory system ______.

A. digests foodB. includes all of the bonesC. carries blood throughout the bodyD. includes muscles and tendons

2. The circulatory system ______.

A. delivers suppliesB. removes wastesC. regulates temperatureD. all of the above

3. The parts of the circulatory system are ______.

A. heart, blood vessels, bloodB. blood vessels, blood, red cellsC. heart, muscles, bloodD. blood vessels, blood, oxygen

4. The liquid part of blood is ______.

A. plasmaB. plateletsC. red cellsD. white cells

5. Each system of the body can work independently, with no help from any other systems.

A. falseB. true

6. Arteries are ______.

A. blood vessels that carry blood to the heartB. parts of the respiratory systemC. the tiniest blood vesselsD. blood vessels that carry blood from the heart

7. The body needs a supply of ______.

A. oxygenB. nutrientsC. bothD. neither

8. If you are exercising outside on a hot day, your face gets red because ______.

A. less blood flows to your skinB. you are breathing slowerC. your heart pumps slowerD. more blood flows to your skin

NameMonday, March 11

Date

Red Blood CellsBy Jennifer Kenny

Red blood cells are one of the four main parts of blood. The other parts are white blood cells, platelets, andplasma. Did you know that there are about twenty-five trillion red blood cells in an adult's body?

Red blood cells are very tiny. One hundred twenty-five red blood cells placed end-to-end would only be onemillimeter long.

Red blood cells are shaped like a doughnut. They are round, but they look like their centers have been partiallyscooped out. Even though they are considered cells, they do not have a nucleus. They are soft and flexible so theycan pass through the capillaries. They can't move on their own, though. Instead, the flow of blood carries them.

Red blood cells are produced in bone marrow, the spongy part inside some of the bones. The mother cells in bonemarrow can make over one hundred million red blood cells each minute.

Red blood cells live for about four months. They become fragile as they get older and begin to lose their shape.When that happens, they are carried to the spleen or the liver where they are destroyed, but parts of them can berecycled into new blood cells.

What is the main job of the red blood cells? They transport oxygen from the lungs to every other part of the body.They also collect carbon dioxide from the body and take it back to the lungs. There is a special protein in red bloodcells called hemoglobin that helps them do this. Actually, each red blood cell contains over two hundred fiftymillion hemoglobin molecules. The hemoglobin makes the blood red. More importantly, though, the hemoglobincombines with the oxygen and carbon dioxide so it can be transported where it needs to go.

Red Blood Cells

Questions

1. The four main parts of blood are white blood cells, platelets, plasma, and ______.

A. oxygenB. red blood cellsC. bone marrow

2. There are about ______ red blood cells in an adult's body.

A. 25 trillionB. 125C. 100 million

3. Red blood cells do not have a nucleus.

A. FalseB. True

4. Red blood cells live for about 120 days.

A. TrueB. False

NameMonday, March 11

Date

5. ______ makes the blood red.

6. What is the main job of red blood cells?

A. carrying oxygen and carbon dioxideB. fighting diseaseC. clotting blood

7. What do you think would happen if the red blood cells weren't doing their job correctly?

Describe red blood cells to someone who has never heard of them.

NameTuesday, March 12

Date

Donating BloodBy Cindy Grigg

A blood bank is a place where blood is stored for emergency use. In theUnited States about every two seconds, someone needs blood. That's over43,000 people every DAY. Not long ago, people with a bad wound mighthave bled to death. Today, blood is donated by people. The donated blood isstored in blood banks to keep it safe for emergency use.

To donate blood, a person must be 17 years old and weigh at least 110pounds. Adults have about 10 pints of blood in their bodies. When blood isdonated, about one pint is taken. The process takes about 10 minutes. Withthe paperwork and recovery time afterwards, a person is usually in and out ofthe donation center in 45 minutes to one hour. January is National VolunteerBlood Donor Month.

One pint of blood can save up to three lives. A pint of blood can be separatedinto its different parts: red blood cells, plasma, and platelets. Donated bloodcan be given to a person as whole blood. Or each part can be given to threedifferent people.

Red blood cells contain iron, and they carry oxygen in the blood. Platelets help blood to clot. Platelets are neededby people with leukemia and other cancers or patients having surgery. Plasma is a mixture of water, proteins, andsalts. Plasma is needed to transport the other blood parts to all the body's cells. Plasma makes up more than half ofthe volume of blood.

Plasma can be frozen and used up to a year later. Red blood cells can be stored for 42 days. Platelets can only bestored for 5 days. The American Red Cross urges people to donate blood so that many lives can be saved.

Donating Blood

Questions

1. If 43,200 people need blood each day, how many people need a blood donation in a year?

2. To donate blood, a person must be ______.

A. 21 years oldB. 35 years oldC. 17 years oldD. 18 years old

3. What is the job of red blood cells?

A. Red blood cells contain iron and carry oxygen in the blood.B. Red blood cells help blood to clot.C. Red blood cells transport the other blood parts to all the body's cells.D. all of the above

NameTuesday, March 12

Date

4. Whole blood can be separated into ______ different parts.

A. twoB. tenC. threeD. five

5. Plasma ______.

A. is a mixture of water, proteins, and saltsB. makes up more than half of the volume of bloodC. can be frozen and used up to a year laterD. all of the above

6. The author's main purpose for writing this story was to ______.

A. persuadeB. informC. entertainD. express personal feelings

Do you know anyone who has received a blood donation? If so, ask this person how he or she feels about theperson who donated the blood. What would the person who received the blood like to say to the person whodonated it? If you don't know anyone who has received blood, write a dialog that you think might take placebetween these two people.

NameWednesday, March 13

Date

White Blood CellsBy Brandi Waters

Caption: Frog blood cells; the white blood cells are the round,dark ones in the center of the picture.

Red blood cells give your blood its red color. They carry oxygenfrom your lungs to all of the cells in your body. However, there ismore to your blood than just red blood cells. More than half of yourblood is made up of a liquid called plasma. It is mostly water, but it isvery important. Plasma helps your blood to flow. It allows your heartto pump your blood through your blood vessels. Red blood cells makeup most of the remaining part of your blood, but there are otherimportant blood components. One of these is white blood cells.

White blood cells may seem a little out of place in your blood.They have little in common with red blood cells. Their job has nothingto do with the heart or blood vessels. White blood cells are like soldiers. Their job is to protect you frominvaders. White blood cells fight germs that try to enter your body. Germs can get into your body through the airthat you breathe and through the things that you eat or drink. They can also get into your body through a cut onyour skin. White blood cells are always looking out for germs. If they find a germ (or many germs), they can callfor help and more white blood cells will come to help. If there is an accident and you have a cut, white bloodcells can also help to prevent germs from getting inside your body. They move quickly to the area that is hurt.They help keep the area clean, help your body to heal, and kill germs.

Normally, there are not very many white blood cells in your blood. If you need them, your body can makemore. If you get a small cut on your knee, you will need a few more white blood cells to help the cut heal and tokill germs. If you get sick with the flu, you will need a lot more white blood cells. After the threat has passed,some white blood cells can remember what the invader looked like. These white blood cells can react veryquickly if that type of germ ever returns. They can act so quickly that they can kill the germ before it can makeyou sick!

White Blood Cells

Questions

1. ______ makes up more than half of your blood.

A. White blood cellsB. Red blood cellsC. PlasmaD. Platelets

2. White blood cells ______.

A. carry oxygen to your cellsB. fight germsC. help your blood flowD. all of the above

NameWednesday, March 13

Date

3. What is the job of a white blood cell?

4. Your body makes more white blood cells ______.

A. when you have a cutB. when you get sickC. when you need themD. all of the above

5. What can some white blood cells do that protects you from getting sick from the same type of germ asecond time?

Doctors can count the number of white blood cells in your blood to help them find out what is wrong with apatient. What does it mean if a patient has a large number of white blood cells in their blood? What does itmean if there are a small number of white blood cells in their blood?

NameThursday, March 14

Date

The HeartBy Jennifer Kenny

The heart is the strong muscle which pumps blood throughout your body. It is a hollowmuscle, about the size and shape of a fist. It is actually made up of two separate pumps. It iscalled an involuntary muscle because it works without you ever having to think about itworking. Isn't that amazing? You'd never get anything done if you always had to think aboutmaking your heart beat!

The heart is located between the lungs and behind your rib cage. It is in a slanting positionin the center of the chest. The pericardium is a covering that keeps the heart from rubbingagainst your lungs and chest wall.

The heart has four chambers in it (right atrium, left atrium, right ventricle, and leftventricle). The muscular wall called the septum divides the two sides of the heart. Bloodcan't pass from one side to the other.

Each side of the heart has an upper chamber and a lower chamber. The upper chambers are called the atria. Theatria are holding chambers for blood entering the heart from the veins. The ventricles are the lower chambers. Theyact like pumps. The walls of the ventricles are thick.

During each heartbeat, the cardiac muscle squeezes hard, forcing blood into the pulmonary artery or aorta (themain artery). The right side of the heart pumps blood to the lungs. The left side of the heart pumps blood away tothe rest of the body.

Valves in the heart control the flow of blood through the heart. Therefore, the blood can go in only one direction.The valves are called the tricuspid valve, the mitral valve, and the semilunar valves.

Your heart continuously beats. For the average adult, the heart beats about seventy times a minute. That amountsto around forty million times a year. Isn't that hard to believe?

The Heart

Questions

1. The ______ is the strong muscle which pumps blood throughout your body.

2. The heart is actually made of ______ separate pumps.

A. 3B. 5C. 4D. 2

3. The heart is a voluntary muscle.

A. TrueB. False

NameThursday, March 14

Date

4. The ______ is a protective covering which keeps the heart from rubbing against your lungs and chest wall.

A. pericardiumB. septumC. valveD. chamber

5. The muscular wall called the ______ divides the two sides of the heart.

A. valveB. pericardiumC. chamberD. septum

6. The ______ are the lower chambers of the heart.

A. ventriclesB. atria

7. The ______ is the main artery.

8. On average, how many times a minute does the heart beat in an adult?

A. 70 timesB. 140 timesC. 4 timesD. 40,000 times

NameFriday, March 15

Date

Keeping Your Circulatory System HealthyBy Brandi Waters

It is important to keep your circulatory system working at its best. Yourheart pumps blood to every part of your body. It travels throughthousands of miles of blood vessels! Blood carries oxygen from yourlungs. If there is a problem with your blood, your heart, or your bloodvessels, your whole body can suffer. If you don't get enough oxygen toyour brain, you might not be able to think clearly. If your stomach isn'tgetting enough oxygen, it might be hard for you to digest your food. Ifthere is a problem with one of your blood vessels, blood could stopflowing to a part of your body. Without it, those cells could die.

What can you do to keep your circulatory system healthy? You canmake sure that you are getting plenty of exercise. When you exercise,you heart beats faster. This makes your heart stronger. Your heart is a muscle. Just like the muscles in your armsand legs, your heart gets bigger and stronger the more that you use it. Exercise also helps to keep your bloodvessels working properly. Go outside and play! Ride your bicycle. Go for a swim. Your body will thank you!

Eat healthy foods. They will keep your circulatory system healthy. Iron-rich foods like beans, whole-grain breadsand cereals, red meat, and green vegetables are good for your blood. Try to avoid fatty foods, especially fried foodsand foods that contain a type of fat called trans fat. Eating too much fat can cause fat to build up in your bloodvessels. This could cause a heart attack. Eating too much sugar can also be unhealthy. It causes inflammation, orswelling, inside your body, even in your blood vessels. One final thing that you can do to keep your circulatorysystem healthy is easy. Do not smoke. Smoking puts many dangerous chemicals in your body. It harms your bloodvessels and heart. It also puts unhealthy gases into your blood. Your cells will get less oxygen. Saying no tosmoking is the easiest way to do something good for your body.

Keeping Your Circulatory System Healthy

Questions

1. Which of the following is NOT a part of the circulatory system?

A. bloodB. blood vesselsC. stomachD. heart

2. Exercise helps to keep your heart healthy because ______.

A. your heart gets stronger when it beats fasterB. your heart pumps less blood when you exerciseC. you make new blood vessels when you exerciseD. all of the above

3. Beans and green vegetables are a good source of ______, which is good for your blood.

A. sodiumB. ironC. vitamin CD. oxygen

NameFriday, March 15

Date

4. Explain how a problem with your circulatory system could affect your brain.

5. What is one thing that you should not do in order to keep your circulatory system healthy?

Exercise is good for your heart. What is your favorite way to exercise? Explain what you like about it.

NameSaturday, March 16

Date

The HeartBy Brandi Waters

Many people think of love when they think about their hearts. They might say, "Ilove you from the bottom of my heart." Sometimes people complain of having abroken heart when they are sad. A person who does something mean might bedescribed as being heartless. Actually, your heart has nothing to do with yourfeelings. Your heart has a much more important job.

Your heart is a big muscle. It is about the same size as your fist. Like all muscles,your heart can "flex." It makes a squeezing motion when it flexes. Your heartdoes this over and over again. This is your heartbeat. Your heart beats to moveblood to all the parts of your body. This process is called circulation. It takes lessthan a minute to move blood to all of the cells in your body! Blood is pumped toyour lungs where it picks up oxygen from the air you breathe. Next, the blood ispumped from the heart to other parts of your body. The blood delivers oxygen toall your cells. It also carries away waste that your cells don't need. This waste iscarbon dioxide. Your heart keeps beating and carries the blood back to yourlungs. There, your blood exchanges carbon dioxide for oxygen. When youbreathe out, or exhale, the carbon dioxide is removed from your body.

Your heart carries oxygen to all the parts of your body. This is why your heart is so important. If your heart stopsbeating, your cells do not have oxygen. They stop working. Your body cannot survive for very long withoutoxygen. Your heart helps to keep you alive.

The Heart

Questions

1. Your heart ______.

A. is a muscleB. carries carbon dioxide to your cellsC. holds your emotionsD. all of the above

2. Your heart's job is to ______.

A. move blood to all the parts of your bodyB. help you breatheC. make you strongD. make heat to keep your body warm

3. Your heart and ______ work together to supply your body with oxygen and to remove carbon dioxide fromyour body.

A. brainB. fistC. stomachD. lungs

NameSaturday, March 16

Date

4. The process that moves ______ to every part of your body is called circulation.

5. How big is your heart?

Why do you think that people have associated the heart with feelings, especially feelings of love? Explain yourreasoning.