1. 1. THE CIRCULATORY SYSTEM Chapter 1
2. 2. Among the systems of the human body, the circulatory system is one of the most interesting but difficult to understand. Tracing the path of the blood from the heart to different parts of the body as it transports food nutrients and gases cannot be easily visualized.
3. 3. PARTS AND FUNCTIONS OF THE CIRCULATORY SYSTEM Lesson 1
4. 4. Everyday, your body needs food in order to stay strong and healthy. Through digestion, this food is broken down into simpler substances that our body cells use. Aside from food, your body also needs oxygen. You have learned that the digested food enters the cells. Oxygen leaves the blood and enters the cells too. Then, the oxygen combines with the digested food. This is called the burning of food. Burning of food gives us energy.
5. 5. As food burns, carbon dioxide and water are given off as waste products. These waste products pass out of the cells and go to the blood. But what body system eliminates these waste products from the body cells? What body system carries digested food and oxygen to the body cells? Where does the blood pass through? What keeps the blood flowing throughout the body?
6. 6. FINDING OUT: WHAT ARE THE MAIN PARTS AND FUNCTIONS OF THE CIRCULATORY SYSTEM? 1. What are the three main parts of the circulatory system? 2. Which is the pumping organ of the body? 3. Which are the pathways through which blood travels around the body? 4. What carried the materials to be transported to and from the body cells? 5. What do you think is the main function of the circulatory system?
7. 7. The circulatory system is the transport system of the body. It carries oxygen and water to all your body cells. It picks up carbon dioxide and other wastes that body cells make. It also carries these wastes to body organs that get rid of them. This system has three main parts namely the heart, the blood vessels and the blood.
8. 8. HEART The heart is connected to a series of tubes containing the blood. It is the most important and delicate organ of the circulatory system. The heart is the pump that circulates blood throughout the body. It is a muscle that contracts and relaxes about seventy times a minute. Each contraction and relaxation of the heart muscle is a heartbeat. You have more than 100,000 heartbeats everyday. Each day, your heart pumps about 13,000 quarts of blood.
9. 9. BLOOD VESSELS The blood vessels are the pathways or tubes in the body through which blood flows. The blood vessels are of three kinds. These are the arteries, veins and capillaries. The arteries carry blood away from the heart. The veins bring blood back to the heart. Capillaries carry blood rich in oxygen to the tissue and carry away waste products.
10. 10. BLOOD The blood is the carrier of food and gases that are transported to and from body cells. The blood travels continuously through a circular path from the heart and back to the heart, thus the name, circulatory system. The process by which food and gases are transported throughout the body is called circulation.
11. 11. WHAT HAPPENS AS BLOOD CIRCULATES? Part of the blood in the heart has just received a fresh store of oxygen from the lungs. This blood is pumped into the aorta. The aorta is the largest artery. Blood is carried from the aorta into a branched system of smaller arteries. From the arteries, it passes into the capillaries. Here the blood gives up oxygen and food materials which have been absorbed from the small intestine and liver to the tissues. Waste material, including carbon dioxide, then passes to the veins. It is returned to the heart by the large veins. The blood is then pumped from the heart through the large pulmonary artery to the lungs. In the lungs, carbon dioxide is given off and oxygen is received. The oxygen-rich blood is then returned to the heart through the pulmonary veins, and another cycle begins.
12. 12. REMEMBERING SCIENCE FACTS The main parts of the circulatory system are the heart, the blood vessels and the blood. The circulatory system is responsible for the distribution of food nutrients and oxygen, and the elimination of carbon dioxide and wastes from the different parts of the body.
13. 13. COMPLETE THE CROSSWORD PUZZLE
14. 14. THE HEART Lesson 2
15. 15. READ THE DIALOGUE Romalyn, do you know how big your heart is? Yes of course! It is as big as my clenched fist.
16. 16. You learned in the previous lesson that the heart is the pumping organ of the body. It is a hollow muscular organ that is protected by the rib and chest bone. But do you know where exactly it is located? What are its parts? What is its function?
17. 17. WHERE IS THE HEART LOCATED? Clench your fist. Locate your heart then place your clenched fist over it. Feel the beating of your heart. 1. Where is your heart located? 2. How big is your heart? 3. What did you feel when you placed your clenched fist over your heart? 4. Why is it beating?
18. 18. WHAT ARE THE CHAMBERS OF THE HEART AND WHAT IS THE FUNCTION OF EACH PART? 1. What are the upper chambers of the heart? 2. What is their function? 3. What are the lower chambers of the heart? 4. What is their function?
19. 19. The heart is the most important organ of the circulatory system. It is a hollow and strong muscular organ. It is about the size of the clenched fist. It is shaped like a pear. Have you seen or eaten a pear? The heart lies between the lungs. It is found only a little to the left of the center of the chest. It is a very delicate organ. Its average weight is 255 grams in women and 340 grams in men.
20. 20. The heart is divided into four chambers. The upper chambers are the right and left atria. The lower chambers are the right and left ventricles. The atria are thin walled chambers. The receive blood from the veins. They hold the blood until it can enter the ventricles. The ventricles are thick walled chambers. They pump blood out of the heart through arteries. They are responsible for helping to keep the blood moving in all parts of the body.
21. 21. A wall called a septum is located between the left and the right chambers of your heart. It prevents the mixing of blood in your heart. The right atrium receives carbon dioxide-rich blood or deoxygenated blood from the lungs while the left atrium receives oxygen-rich blood or deoxygenated blood from the lungs.
22. 22. There is an opening between the auricle and the corresponding ventricle on each side of the heart. These two openings are guarded by valves. A valve is a thin membranous tissue in a tube. It is a special one way opening. The valve between the right atrium and the right ventricle has three flaps. It is called the tricuspid valve. There are only two flaps in the valve between the left atrium and left ventricle. This is called the bicuspid valve. It is also known as mitral valve because with its two flaps it looks something like a bishops miter. The aortic and pulmonary valves, two other valves, guard the exits from the ventricle. The aortic valve is found at the beginning of the aorta. The pulmonary valve is located at the beginning of the pulmonary artery, which carries blood to the lungs. The valves between each atrium and ventricle prevent the backflow of the blood. Valves between the ventricles and the arteries also keep the blood from flowing backward.
23. 23. REMEMBERING SCIENCE FACTS The human heart consists of four chambers: the right atrium, left atrium, right ventricle and left ventricle. The atria are the receiving chambers of the heart. The ventricles are the pumping chambers of the heart. The septum is located between the right and left chambers. It prevents the mixing of blood in your heart. The valves between atrium and ventricle prevent the backflow of blood.
24. 24. COMPLETE THE WORD SEARCH AS A CLASS
25. 25. THE BEATING HEART Lesson 3
26. 26. Does the heart beat continuously? Why does it keep on beating? The heart is the most hardworking muscle in your body. Its main function is to pump blood throughout the body. It keeps on pumping blood even when you are at work, at rest or sleeping. It send blood through the blood vessels of your body by beating constantly, about 60-80 times every minute when you are at rest. The beating of the heart and the flow of blood are not easy to observe. However, there are some parts of the body where you can feel the arteries that carry your blood beating in time with your heart. This is called pulse. What are these areas where you can feel your pulse?
27. 27. WHERE DO YOU FIND YOUR PULSE? HOW DO YOU MEASURE IT? 1. Locate the areas in your body where you can feel the pulse. Start from your wrist. Do not use your thumb because you can feel a conflicting pulse there. 2. Press your index and middle fingers against your wrist near the base of your thumb and sit calmly for two minutes. 3. Then, count your pulse beat for one minute. Do this five times. 4. Find your average pulse by dividing your total pulse beat by five. Findings: 1. Where did you find your pulse? 2. What did you do to measure your pulse? 3. What is your average pulse rate?
28. 28. WHY DOES THE RATE OF THE HEARTBEAT CHANGE? 1. Take your pulse. 2. Dance for two minutes. 3. Take your pulse. 4. Rest for two minutes. 5. Take your pulse. Findings: 1. Did your heartbeat/pulse rate change? Why? 2. How did your heartbeat while dancing? 3. Compare your three pulse rates.
29. 29. You already know that the pulse can be found at the wrist. There are other areas in your body where the pulse can be found. Some of these spots are in the temple, in the neck, at the crook of the elbow, back of the knee, and front of the ankle. The throbbing inside these parts of the body is known as a pulse. Your heart and pulse beat at the same time. The beating of your heart sends the blood surging through the arteries. With every heartbeat, there is a high pressure surge through the arteries. These surges can be felt as a pulse at the wrist, temple and other areas where the arteries are near the surface of the skin.
30. 30. Do you know why we usually measure our pulse rate instead of our heart rate? We usually do this because it is easier and more convenient to take the pulse rate than the heart rate. The pulse rate can be measured by putting your index and middle fingers at your wrist or in the other areas where you can feel your pulse. With each heart beat, a pulse wave spreads all over the arterial system. The succession of waves can be felt as a series of taps if the finger is pressed lightly over any large artery. To count the number of heartbeats per minute, the physician generally presses on the radial artery, which passes through the wrist.
31. 31. The pulse rate varies greatly in individuals. Your pulse rate is about 90 times a minute. The average rate for adults who are relaxed mentally and physically is from 70 to 75 in women and from 65 to 70 in men. It is much higher in babies. The count usually slows down when you are asleep. The rate of the heartbeat and pulse beat changes. When you do strenuous activities such as dancing, running or working hard, your pulse rate may reach 200 per minute. Your pulse rate also speeds up when there is a strong emotion or you become greatly excited. Various bodily conditions such as surgical shock, fever and hemorrhage also cause marked increase in the pulse rate. When you do light activities such as sitting, lying or sleeping, the pulse rate slows down. These activities do not require much energy. You do not need much oxygen, thus, your heart beats slowly. You breathe slowly too. Do you know that an adults heart at rest pumps almost gallon of blood every minute or 2100 gallons each day?
32. 32. YOUR HEARTBEAT AND THE PACEMAKER Your nervous system regulates your hearts pumping rate. At the back of the right atrium is a control center called the pacemaker. The pacemaker is part of the heart. It is a small area of tissue which controls the heartbeat. It does this by sending out impulses. The impulses tell the heart how fast and how often to pump out blood. When you are at rest, the impulses signal the heart to contract at a slow pace. But when you are doing a strenuous activity such as exercising, your muscle cells send impulses to the brain. These impulses tell the brain needs more oxygen and nutrients. The brain sends this message to the heart by way of the pacemaker. The heartbeat speeds up, thus moving the blood through the body more rapidly. In this way, the pacemaker which automatically keeps the heart beating, slows down or speeds up according to the bodys needs.
33. 33. HEARTBEAT Heartbeat is the alternating contraction and relaxation of ventricles. It can be heard through a stethoscope because its soft sound is channeled through the tube of the stethoscope leading to the ear. When a physician puts a stethoscope to your chest, he/she can generally hear two sounds as the heart beats. The first is the lub sound. This sound is softer and lower in pitch. It lasts longer. The second sound is the dub sound. This sound is sharp and short. The two sounds occurs in quick succession and are followed by a slight pause. The physician listening to the stethoscope hears something like lub-dub, lub-dub, lub- dub.
34. 34. LUB-DUB The lub-dub sounds that you hear are the opening and closing of the valves in your heart. The valves allow the blood to flow only in one direction. When the ventricles contract, the valves open to allow the blood to flow from the heart. Thus, you hear a lub sound, when the ventricles relax. The valves close tightly to prevent the blood from flowing backwards. Thus, you hear a dub sound. Therefore, count each lub-dub as one beat. The heartbeat is not initiated by the action of nerves, but it is affected by two sets of nerves arising in the medulla oblongata, a part of the brain. These are the vagus nerves and the accelerator nerves. The vagus nerves act as brakes. They slow down the heart and reduce the strength of its beats. The accelerator nerves, on the other hand, speed up the heart and increase the strength of the heartbeats.
35. 35. Blood flows into the relaxed atria. The wave of contraction squeezes blood into ventricles. Blood is squeezed out the ventricles into the arteries. Blood starts to fill up the now relaxed atria again.
36. 36. REMEMBERING SCIENCE FACTS The pulse is found at the wrist, in the temple, in the neck, at the crook of the elbow, back of the knee and front of the ankle. The rate of the heartbeat/pulse changes. Pulse rate can be measured by putting the index and middle fingers at your wrist, neck and other areas where the pulse can be felt. Pulse rate varies from one person to another. Strenuous activities and strong emotions make your heart beat faster. Light activities make your heart beat slower. Heartbeat is the alternating contraction and relaxation of ventricles. The lub sound represents the opening of valves. The dub sound represents the closing of valves.
37. 37. TRUE OR FALSE? 1. The pulse is felt easily in any part of the body. 2. The blood pumps throughout the body. 3. The heart and pulse beat at the same time. 4. The pulse can be felt at the temple. 5. The pulse can be felt in areas where the arteries are near the skin.
38. 38. THE BLOOD VESSELS Lesson 4
39. 39. THE BLOOD VESSELS Your circulatory system is a closed system. This means that except when a part of the system is injured or opened, all of the blood remains trapped in the system. Your blood follows the same paths over and over again throughout your body. Your blood vessels are a group of tubes with different sizes that are the pathways through which blood flows and transports food to all parts of the body. Blood vessels are of three kinds. These are the arteries, the veins and the capillaries. Look at your inner wrist. What are those bluish lines that you see? These bluish lines are your blood vessels. How would you describe each blood vessel? What is the function of each blood vessel?
40. 40. WHAT ARE THE KINDS OF BLOOD VESSELS? WHAT IS THE FUNCTION OF EACH? 1. Look at your inner wrist and find the bluish lines. 2. Look at the figure of the circulatory system. 3. Identify the different blood vessels and label them. 1. What are the different kinds of blood vessels? 2. Which blood vessel carries the blood back to your heart? 3. Which blood vessel carries the blood away from the heart? 4. What are the tiny tubes called and what is their function?
41. 41. BLOOD FLOW Blood is transported to all parts of the body and back again through a system of tube-like vessels. These vessels are of three kinds: the arteries, veins and capillaries.
42. 42. ARTERIES The arteries carry blood containing oxygen or oxygenated blood from the heart to all parts of the body- to the brain and stomach. What is the color of the blood that comes from the heart? It is red because of the combination of the oxygen and the red blood cell. The arteries into which the ventricles pump blood are elastic and tough vessels. Their walls are made up of three coats. The inner coat consists of a delicate and thin cellular lining. The middle coat is made up of smooth muscle fibers and elastic connective tissue. The connective tissue of the outer core has nerves and small blood vessels. The elasticity and thickness of the artery make it resistant to high pressure. They also allow them to expand and contract. Every time the heart beats, arteries expand. Then they contract, helping to push the blood along.
43. 43. Arteries have different sizes. Those ones near the heart are bigger than the other arteries of the body. Arteries from the heart branch out, growing into smaller tubes called arterioles. Arterioles still branch into smaller tubes. These tiny tubes are the capillaries. You need a microscope to see them.
44. 44. CAPILLARIES The capillaries are the tiniest blood vessel. They are longer than all the arteries and veins joined together. The capillaries at the end of the arteries carry the digested food and oxygen. When the blood reaches the cells, the digested flood and oxygen leave the blood and enter the cells. At the same time, waste materials like carbon dioxide leave the cells and pass into the capillaries again. Thus, the actual exchange of materials between the blood and connective tissue fluid occurs in the capillaries.
45. 45. VEINS Capillaries lead into another kind of blood vessels called veins. The veins carry blood containing carbon dioxide from the cells back to your heart. This blood is sometimes called used blood or deoxygenated blood. Why do you think so? Veins are closer to the surface of your bodies than arteries. They are bluish in color. Our skin acts as a color filter. Thats why we see them as blue. Did you know that if all the blood vessels in your body were laid end to end they would stretch almost three times around the widest part of the earth?
46. 46. REMEMBERING SCIENCE FACTS The three kinds of blood vessels are the arteries, veins and capillaries. The arteries carry oxygen-rich blood to the different parts of the body. The veins carry blood containing carbon dioxide away from the heart. The capillaries are the smallest kind of blood vessels. They carry blood rich in oxygen to the body cells and carry away waste products.
47. 47. MATCH COLUMN A AND B A 1. Carry blood away from the heart 2. Carry blood back to the heart 3. Where the actual exchange of gases takes place 4. These are the smaller arteries 5. The blood passing through the arteries 6. Color of the blood coming through the heart 7. Waste material that leaves the cells of the body 8. Materials that are carried to the cells of the body 9. Acts as a color filter 10. Color of veins that are closer to the surface of the body B A. Arteries B. Arterioles C.Capillaries D. Veins E. Red F. Blue G.Skin H. Oxygenated blood I. Deoxygenated blood J. Carbon dioxide K. Digested flood and oxygen
48. 48. THE BLOOD Lesson 5
49. 49. THE BLOOD Blood is another part of the circulatory system. It is called the red river of life. It is called so because the blood supplies the body cells with the materials they need for nourishment and repair, and it eliminates wastes from the cells. In addition, the blood contains cells that fight disease and a substance that repairs bruises or cut parts of the body. The blood is pumped through the body by the heart. It carries digested food and oxygen to all body cells and takes away waste materials from them. Blood flows into your heart before each beat, then your heart squeezes it out to continue its journey.
50. 50. Did you know that your blood is a liquid tissue? It makes up 7 to 9% of your total body weight. An adult male has about five to eight liters of blood in his body. In females, there is a slightly lower volume- about four to five liters. The blood is composed of the plasma, the platelets, the white blood cells and the red blood cells. Blood appears to be a liquid. But it is really made up of two parts: the liquid part and the solid part. The liquid part is the plasma. The solid part is the platelets and blood cells.
51. 51. PLASMA Plasma is a clear yellow fluid that surrounds the platelets and tiny blood cells that make up your blood. Plasma is a solution of salts, water and chemicals. It is about 55% of the bloods volume. Plasma carries: Antibodies used by your body to fight disease-causing germs Digested food to the cells Wastes from the cells of your body to the lungs, kidneys and liver Sugar and hormones to all parts of the body The plasma also contains several different proteins, including Fibrinogen. Fibrinogen is a blood protein that plays an important role in blood clotting.
52. 52. PLATELETS Platelets are tiny discs that develop from cells produced in the bone marrow. They float in the plasma. The billions of platelets in the body help to make the blood clot. A clot is a soft solid mass that forms outside your skin when you have a cut or wound. It helps stop the bleeding. Do you know what happens when you have a cut? When an injury tears open a blood vessel, the platelets stick to the wall of the broken blood vessel. Fibrinogen gathers on the platelets and changes into a tangled network of fine threads. The platelets and fibrinogen together form a clot. The clot closes the vessel walls and stops bleeding.
53. 53. RED BLOOD CELLS OR CORPUSCLES Red blood cells or corpuscles are produced in the red marrow of bones. The word corpuscle is the Latin word for little body. RBCs contain hemoglobin, the red pigment of the blood. They carry oxygen and carbon dioxide. There are about 250 million red blood cells contained in a drop of blood.
54. 54. WHITE BLOOD CELLS White blood cells are the soldiers of the body. They serve as antibodies. They fight infections in your body. They attack and destroy disease carrying organisms that get into the bloodstream. There are about 500 red blood cells for every one white blood cell.
55. 55. BLOOD TYPES A healthy person has about five quarts of blood. When people meet an accident, they may lose blood and need it to save their lives or speed their recoveries. Other people need extra blood to make up for a deficiency or lack of a vital substance in their blood. This requires blood transfusion. Blood transfusion is the taking of blood from one person and putting it into the circulatory system of another person. A blood donor is the person who gives blood for another person to use.
56. 56. DONATING BLOOD Donating blood is not painful or difficult. It does not harm the donor because the donors blood supply is renewed. It is taken from a donor through a germ free needle inserted into a vein in the arm. The blood flows into a collection bag. Inside it, it is separated into white blood cells, red blood cells, platelets and plasma or blood serum. Blood serum is blood plasma without clotting agents.
57. 57. BLOOD TYPES Karl Landsteiner, a Nobel prize-winning scientist, discovered that there are four main types of human blood, which he classified as A, B, AB, and O. Knowing your blood type is important because in blood transfusion, a person with one kind of blood would become ill if he received another kind that did not agree with him. In addition, if blood that is transfused does not match the patients own blood, the new blood may cause the red blood cells to clump together. If these clumps pass through the brain or the heart, they may kill the patient.
58. 58. The table below shows the blood type, donor and receiver. Type O is known as a universal donor. A person with type O blood can donate moderate amounts of blood to people of any blood type. What is your blood type? To which types can you donate blood and receive blood? A Donates to Receives from A A, AB O, A B B, AB O, B AB AB O, A, B and AB O O, A, B, AB O
59. 59. REMEMBERING SCIENCE FACTS The blood is composed of the plasma, platelets, red blood cells and white blood cells. Plasma is the liquid part of the blood. It transports digested food to the cells and carries waste materials. Platelets help stop bleeding when you have a cut or wound. Red blood cells carry oxygen and carbon dioxide. White blood cells fight infections in your body. The different blood types are A, AB, B and O.
60. 60. IDENTIFY THE COMPONENTS OF THE HEART 1. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -soldiers of the body 2. _ _ _ _ _ -red river of life 3. _ _ _ _ _ _ -carries digested food and wastes 4. _ _ _ _ _ _ _ _ _ -help stop bleeding 5. _ _ _ _ _ _ _ _ _ _ _ _ _ -carry oxygen and carbon dioxide
61. 61. HOW BLOOD CIRCULATES Lesson 6
62. 62. HOW BLOOD CIRCULATES In the previous lesson, you learned that the heart pumps blood throughout the body. Its four chambers the right atrium, right ventricle, left atrium and left ventricle perform an important role in the distribution of blood. The blood in its trip carries food nutrients and oxygen which the body needs and picks up carbon dioxide that has to be eliminated from the body. The blood passes through the different blood vessels: the arteries, veins and capillaries. These blood vessels likewise have certain work to do in order for the blood to complete its trip. We will now trace the circulation of the blood throughout the body.
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