Science 2 part 2

IISCIENCE PART 2

Module 10 Musculo-Skeletal System What this module is about Are you amazed at the wonder of the work of the human machine? Get ready foranother trip to a more complex part of the body, your musculo-skeletal system. You often think of bones as those parts of the body that remain long after the softerorgans of a dead body have decomposed. However a living bone is quite different from theremains of a dead body. It is a living organ, richly supplied with blood. It requires oxygenand nourishment and it responds to the care you give. This module has 3 lessons, namely:  Lesson 1 – Skeletal System  Lesson 2 – Muscular System  Lesson 3 – Bones and Muscle Problems What you are expected to learn After going through this module, you are expected to: 1. Discuss the purpose of the skeletal system. 2. Describe some important parts and explain their functions. 3. Tell how bones are connected to the muscles. 4. Distinguish the different types of joints. 5. Locate places where this type of joint is found. 6. State and explain the functions of the muscular system. 7. Classify muscles according to types and functions. 8. Discuss the causes of some of the more common problems of the bones and muscles. 9. Explain ways of preventing the problems of the bones and muscles.

How to learn from this module1. Read and follow instructions carefully2. Answer the pre-test before you start the lesson.3. Take note and record points of clarification.4. Try to achieve at least a 75% level of proficiency in the tests.5. Work diligently and honestly.6. Answer the posttest thoroughly.What to do before (Pretest)Multiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. The main support system of the body is/are thea. blood c. musclesb. bones d. skin2. Which organs are protected by the rib cage?a. heart and lungs c. ovaries and testesb. brain and spinal cord d. small and large intestines3. If there were no bones, the muscles would drop to the ground. Which function of the bone is shown here? a. protects the heart and lungs b. provides leverage for movement of muscles c. forms a strong case for delicate organs d. provides anchor to which muscles are attached4. It is estimated that there are __________ bones in an adult.a. l06 c. 306b. 206 d. 4065. What are bones made up of? c. osteoblast a. calcium d. phosphorus b. collagen6. What bony cavity protects the brain? c. ribs a. cranium d. spinal column b. pelvis -2-

7. What nutrients give bones their strength and shape?a. calcium and iron c. iron and phosphorusb. calcium and phosphorus d. iodine and phosphorus8. As bones grow older, they harden because of bone cells and minerals. What do you callthis process?a. ossification c. osteomalaciab. osteoarthritis d. osteoporosis9. What do you call the point where two bones meet?a. joint c. marrowb. origin d. insertion10. A lubricating fluid that helps the bones move smoothly over one another is calleda. cerebrospinal fluid c. oilb. grease d. synovial fluid11. There are about __________ muscles in the human bodya. 300 c. 500b. 400 d. 60012. Muscle fibers have the power of shortening. This is also referred to asa. contraction c. originb. insertion d. relaxation13. The connective cord which attaches a muscle to a bone is thea. cartilage c. ligamentb. joint d. tendon14. The point of attachment of a muscle that remains fixed during muscular contraction isreferred to asa. insertion c. originb. joint d. tendon15. Muscles that move when we want them to move are calleda. cardiac c. skeletalb. involuntary d. smooth16. The essential function of a muscle is for c. pumping a. contraction d. pushing b. relaxation17. Where can we find cardiac muscles in the body?a. chest c. heartb. face d. pelvis -3-

18. Which muscles are found in the walls of the hollow organs of the body like stomach,urinary bladder, etc?a. cardiac c. skeletalb. involuntary d. voluntary19. The movable bony attachment of muscles is thea. insertion c. originb. joint d. tendon20. All of the statements below are true about muscles EXCEPT one. Which is it?a. Muscles can contract. c. Muscles can push.b. Muscles can pull. d. Muscles have at least two attachments. Key to answers on page 21.Lesson 1. The Skeletal System Why do builders put up a wood/steel frame for a house? Why are there aluminumframes in an umbrella? The wood/steel frame supports the walls and roof of a house just asthe aluminum frame supports the umbrella. These frames which provide support are alsoknown as framework. Animals have a framework similar to the framework of a home. The framework inanimals is called the skeleton. In animals, the framework has muscles attached to it insteadof walls or roof. The skeleton has a number of jobs. These jobs are related to the protection, support,and movement of the body. The skeletal system provides form and support to the body. Without a skeleton youwould not be able to walk, talk, or lift objects. There would be little protection to your brainand internal organs. In fact, without bones you would be a formless being. Bones serve thefollowing functions:  Protect the vital organs inside the body.  Provide anchor or support to the muscles.  Produce blood cells. To help you better understand the function of bones, perform the activity on the nextpage. -4-

What you will do Activity 1.1 Knowing the Functions of the BonesPrepare the following materials: Paper doll Piece of wire as tall as the paper doll Masking or adhesive tapeProcedure: 1. Cut a paper doll and make it stand on the table. 2. Attach the paper doll to the wire using the adhesive tape. 3. Bend the wire in different directions and observe what happens to the paper doll.Answer the following questions: a. Did the paper doll stand on its own? b. Did the paper doll stand when it was attached to the wire? Why or why not? c. What function did the wire play in relation to the paper doll? d. What happened when you bent the wire in different directions? e. What part of the body can be compared to the wire in this activity? f. What help does the backbone offer in bending? Key to answers on page 21.Did you enjoy the activity? I’m sure you did. Now proceed to the next interesting topic.Bones A bone is alive and is made of cells just like other organs and body parts. Becausebone cells are living, they can reproduce resulting in the hardening of the bones calledossification and bone growth. You know that bones grow because you are taller now thanwhen you were younger. Not only does bone size change, their number also changes. As you grow thenumber of your bones increases although some bones fuse. This could not happen if boneswere not alive. Figure 1 shows the parts of the skeletal system. The skeletal system includes thebones, cartilage, ligaments, and tendons. These are tissues that make up the skeleton.A bone is a hard, living tissue and contains blood vessels, nerves and dividing cells. Most -5-

bones are hollow, or at least spongy inside. Thehollow center of the bone is the marrow. Themarrow produces red and white blood cells andstores some of the body’s excess fat. Cartilage is a tough, flexible tissue.Cartilage is the one cushioning the ends of thelong bones where they meet. You can feel thecartilage in your earlobes and the lower part ofyour nose. Cartilage is also found in the walls ofthe voice box and in the windpipe. Ligaments attach one bone to anotherwhere two bones connect. Ligaments are toughstrands of connective tissues. It is the ligamentsthat hurt when you sprain an ankle. Tendons are tissues that connect thebone to a muscle. Have you ever seen the thin,pink, tough membrane covering the outside ofthe bone? This is the periosteum, a tough,living membrane that covers all the bone exceptthe ends. This is richly supplied with bloodvessels. The periosteum is necessary fornourishing the bone, for producing bone cell andfor repairing injuries. Figure 1 Parts of the Skeletal System http//www.sirinet.ml/~jgjohnso/biologyII.htmlWhat you will doActivity 1.2 Test for Calcium In Different BonesMaterials:acid in dropping bottle glass slidechalk pig’s meatcow bone chicken bonewoodProcedure:1. Make a chart similar to the one shown on the next page to record your data. -6-

2. Place a piece of chalk on a glass slide.3. To see the effect of the acid on calcium, put a drop of acid on the chalk. Reminder: Do not spill acid on skin or clothes. If spillage occurs, rinse with water and call your teacher. The bubbles that form tell you that calcium is present.4. To see the effect of the acid when calcium is not present, put a drop of acid on the glass slide. No bubbles form. Calcium is not present.5. Record the results from steps 3 and 4 in your data chart.6. Test each of the skeleton parts listed in the materials list to see if calcium is present. Add only one or two drops of acid to each skeleton part. Make sure that each part to be tested is on the glass slide.7. Record your results in the chart.Data and Observations: Item Tested Bubbles Form with acid? Is calcium present?Chalk (Yes or No) (Yes or No)GlassCow boneChicken bonePigs meatWoodAnswer the following:1. How can you tell if a skeleton part contains calcium?2. How can you tell if a skeleton part does not contain calcium?3. Which of the skeleton parts did have calcium?4. What is the job of calcium in a skeleton?5. Would you expect to find calcium in pig’s meat? Why or why not? Key to answers on page 22. The ends of bones are covered with articular cartilage. This provides a smoothsurface so that two bones can glide over each other. The bone tissue near the joints is loose or spongy and has the ability to absorbmechanical shock. This is the spongy layer. It contains the bone marrow, which producesred blood cells and most of the white blood cells. -7-

Between the joint ends the bonenarrows into the slender area called theshaft. At the center of the shaft is themedullary canal, filled with yellow marrow.Most cells in this marrow are fat cells.(Figure 2) Figure 2. Parts of a Bone Shaft http//www4.tpgi.com.au/users/amegann/body/ skeletal.html Beneath the periosteum is a hard bony layer. There is a network of canals runningthroughout the bony layer. These are called haversian canals, which contain bloodvessels that supply nourishment to the bone cells. The human skeleton has 206 bones. There are five main parts of the skeleton - theskull, rib cage, back bone or spinal cord, front appendages which includes the hands,arms, shoulders and collar bone and the back appendages composed of the feet, legs,knees and hip bone. The main part of the human skeleton is the backbone. The backbone is not a singlebone. It is made up of thirty-three small bones called vertebrae. About one fourth of thebones, more than fifty, are located in a person’s two hands. Six of the bones are the tiny,bony parts of the inner ear. Exercise, correct posture and eating foods rich in calcium and phosphorous are goodfor the bones. What you will do Self-Test 1.1 1. What are the four main parts of the skeletal system? 2. What is a bone? -8-

3. What is a cartilage? 4. What are tendons? 5. What are ligaments? 6. What are the five main parts of the human skeleton? Key to answers on page 22. What you will do Activity 1.3 Palpation (Touching) Now, you are ready to perform a very interesting activity. Explore some parts of yourbody by observing and palpating or touching them as you work through this exercise. 1. Run your finger over the surface of your head. Notice that the underlying skull or cranium lies very near the surface. The skull protects the brain. 2. Spread your fingers on the skin of your face and feel it bunch and stretch as you smile, frown and make “faces”. You are now monitoring the action of the muscles of your face. 3. Run your fingers along the middle of your back and feel the spine or the vertebrae. The spine protects your spinal cord. 4. Touch your collar bone along its entire length from the breastbone to the shoulder. 5. From the breastbone, feel the ribs, the bones that protect the heart, lung, liver and other delicate organs. 6. Now, work your elbow – flexing and extending it – feel the ulna moving in and out on the backside of the upper arm. 7. Clench your fist and find the joint protrusions beyond the wrist. 8. Rest your hands on your hips. Feel the pelvic bones. These protect your reproductive organ and other parts. 9. Touch your ankle. Now feel the whole part of the ankle. 10. Move your fingers toward the heel bone. Did you enjoy the activity? How did you feel while touching some of the bones andmuscles of your body? Were you amazed at the various parts that you have touched?Palpation or touching can also help locate broken bones and inflamed muscles in your body. Do you know why you can move your knee, elbow, arm, or bend your body? This isbecause the skeletal system has joints. -9-

The Joints that Connect Bones A joint is a place where two bones meet. Most joints are movable. There may besome cartilage and fluids at the ends of the bones. This permits the joints to move smoothlywithout damaging the bones. There are five kinds of joints. Look at Figure 4 to know thelocation of the different kinds of joints. Hinge Joints - like the door hinge, a hinge joint can only move in one direction – up or down. Your knee and elbow are hinge joints. Study carefully the illustration of a hinge joint at the right. Notice the tendon, ligament and cartilage.• Pivot Joints - the pivot joint Figure 3. Hinge Joint allows rotation. Your wrist and where your head is attached to http//www4.tpgi.com.au/users/amegann/body/ skeletal.html the spinal chord are pivot joints. This is why you can turn a doorknob with your hand and turn your head.• Ball-and-Socket Joints - ball-and-socket joints allow you to turn your arms and legs in a complete circle. There is a ball or knob at the end of one bone. At the end of another is a hole or socket. A joint is formed where the ball fits into the socket. Shoulder joints and hip joints are ball-and-socket joints.• Gliding Joints – a gliding joint allows two bones to move one over another. These are only found between the vertebrae in the backbone. The amount of movement is small.• Fixed joints - joints where the bones are tightly joined together and cannot move. The skull bones are fixed joints. Figure 4. Joints of the Human Bodyhttp//www4.tpgi.com.au/users/amegann/body/skeletal.html - 10 -

What you will do Activity 1.4 Examining a chicken bone1. Carefully cut and peel away the skin and meat of a chicken thigh.2. Remove the thin sheet of outer tissue covering the bone.3. Observe the exposed layer. This is the periosteum.4. Feel and observe the substance where bones come together. This is the joint.5. Look for a white substance covering the ends of the bones. This is the cartilage.6. Pick away the meat at the small end of the drumstick. Locate the round, tough piece of tissue. This is the tendon.7. Carefully bend back two bones and crack a joint. Do not tear the bones apart. Find the tissue that is tough and crunchy which help hold the bones. This is the ligament.8. Slice open lengthwise the leg bone. Observe carefully the inside parts. Locate the solid bone, marrow and spongy bone.Lesson 2. The Muscles A cat strikes out at a rat to capture it. With a quick turn, the rat moves away toescape. Both animals use their muscles for movements. Muscle is a special kind oftissue that brings about movement.The kind of movement that musclescarry out depends on where themuscles are located. Withoutmuscles your bones and joints willbe useless. Bones cannot move bythemselves. Moving, breathing andswallowing would be impossiblewithout muscles. Muscles, the organs of the Figure 5. The Muscular Systemmuscular system (Figure 5), consistlargely of muscle cells that are http//www4.tpgi.com.au/users/amegann/body/ muscular.htmlspecialized to undergo contraction.During this contraction, some of thechemical energy of nutrients isconverted to mechanical energy ormovement. The front view of themuscular system is shown below. - 11 -

When muscles contract, they pull the body parts to which they are attached. Thisaction usually causes some movement, as when the joints of the legs are flexed andextended during walking. At the other time, muscular contraction resists motion, as whenthey help the body parts in postural positions.Muscles are also responsible for themovement of the body fluids such as bloodand urine, and they function in heatproduction that helps maintain bodytemperature. There are 600 muscles in the humanbody. Most muscles are attached to bonesand extended from one bone to another.Each end of the muscles is attached to abone by a strong connective tissue, a tendon.Bones of the muscles move only when themuscles attached to them pull. Muscles do not push; they only pull. Figure 6. The MusclesThis is why most muscles come in pairs. Themuscles of your arm are good examples of http//www4.tpgi.com.au/users/amegann/ body/how muscles work as partners. The two muscular.htmlmuscles of your arms are called biceps andtriceps (Figure 7). The biceps is a flexormuscle. It produces a flexing or bendingaction by pulling the lower arm bone at thejoint towards the body. The triceps is anextensor muscle. It produces an extending orstraightening action by returning the bone tothe relaxed position. Not all muscles are connected to the bones. For example, heart muscles work bysqueezing. Some muscles are connected to the skin. This is how you are able to smile bymoving fourteen muscles. It takes 75 muscles to frown.Figure 7. Muscles of the Upper Armshttp//www.sirinet.ml/~jgjohnso/biologyII.html - 12 -

Types of Muscles There are three kinds of muscles: (1) Skeletal muscle, also known as striated orvoluntary; (2) Smooth or involuntary muscles, which forms the muscle layers of the digestivetract and other internal organs; and (3) cardiac or heart muscles. Do you know that one type of muscle makes up about half of your body weight? Thisis the skeletal muscle. The skeletal muscle as shown below consists of a mass of muscle fibers groupedtogether and are attached to bones. This muscle has a striation when seen under amicroscope. Striped or striated muscles are used to make fast, precise movement. A person can control the use of striped muscle. A muscle that can be controlled is avoluntary muscle. Figure 8 The smooth muscles in the drawing below are made of long, thin cells that formlayers like a pile of rags. A person cannot decide to move smooth muscles. They cannotbe controlled. The smooth muscle is a type of involuntary muscle. Figure 9 Smooth muscles control many of the internal organs of the body. Examples ofsmooth muscles are the muscles of the stomach, arteries and uterus. Cardiac muscle is found only in the heart. The cardiac muscle works like a smoothinvoluntary muscle. - 13 -

The illustration below shows a sample of a cardiac muscle. The cardiac musclelooks like bundles of fibers twisted into a rope. Fibers from one bundle branch into the nextbundle. Thus, the bundles of cardiac muscles are all connected and can work together tokeep the heart pumping. Figure 10 Pictures retrieved from http//www.archive NCSA.uiuc.edu. Muscle is a special kind of tissue that can contract. The size of the muscle increaseswith use. To remain healthy, a muscle must be regularly exercised. Without exercise, itundergoes atrophy (reduce in size); with extremely vigorous exercise, it undergoeshypertrophy (increase in size). What you will do Activity 2.1 Types of MusclesFill up the chart below. Check (/) whether the action is done by voluntary, involuntary orcardiac muscles. Actions Involuntary Voluntary Cardiac1. Yawning2. Running3. Skipping4. Breathing5. Shivering6. Blinking of the eyes7. Heart beating8. Digesting food9. Stretching arms10. Playing piano Key to answers on page 22. - 14 -

Lesson 3. Bone and Muscle Problems Do you want to know more about bones and muscles? Get ready for anotherinteresting lesson. From studying this module, you know that the skeletal and muscular systems worktogether. So, a problem in one system may cause a problem in the other. Modern scienceis able to help solve some of the problems that affect the skeletal and muscle systems.Skeletal Problems Some problems with the skeletal system are diseases of the joints. Arthritis is adisease of bone joints. One type of arthritis results in breakdown of the bone at the joints.The result is pain and swelling at the diseased joint. In time, a person may not be able tobend or move that part of the body. Today there are some help for the problems of arthritis. Artificial joints made ofplastic or metal are sometimes used to replace diseased joints. Joints such as hip, ankle,and knee have been replaced. It is made of metal and replaces the ball part on the femur ofthe ball and socket joint in the hip. Most bones in the body are connected to each other by tight bands called ligaments.Have you ever twisted your ankle? If you have, the pain you felt was caused by injury toyour ankle ligaments. Sprains are injuries that occur to your ligaments. In some cases, youmay have stretched the ligaments around the ankle. This stretching takes only a short timeto heal. A more serious sprain results when the ligaments are torn. Torn ligaments aremore painful than stretched ligaments and take much longer to heal.Figure 11. Types of Fractures Probably the most common disorder of the musculo-skeletal system is a fracture.nml.nih.gov/medlineplus/ency/imagepages Although the most frequent cause of117259.htm fractures is that of trauma, some are the result of a bone disease that causes weakening of the structural supports that break with little or no actual trauma (injury caused by shock, violence) e.g. wound. Study figure 11. This shows the different types of fractures: green stick fracture or simple fracture, comminuted fracture, and compound fracture. The fractures may occur because of such conditions as cancer of the bone, osteoporosis (porous bones), or complication from prolonged therapy. - 15 -

Dislocations. A dislocation is Figure 12. Bone Dislocationmore severe than a sprain. The boneends are moved out of place at the joint, nml.nih.gov/medlineplus/ency/imagepages 117259.htmand the ligaments holding them areseverely stretched or torn as shown inthe figure on the right. Note that thebone (radius) is not connected to theother bone below. A dislocation must be set into anormal position and held during healingwith a bandage or cast as support. To see how dislocation andfracture differ, do the activity below. What you will do Activity 3.1 Distinguishing Dislocation and FractureA. 1. Get a chicken wing. 2. Remove the skin and meat. 3. Locate the joint. 4. Twist the bones of the lower and upper wing in opposite direction so that bones will be out of place. 5. Observe what happens to the alignment of bones. This result in a dislocation.B. Using the same wing break the bone. Observe. This is a fractured bone.What you have done and observed is comparable to the same problems of the humanskeleton. Bursitis. A bursa is a small sac situated near a joint. There are 52 of these sacs inyour body. Bursas lie between tendons that rub each other, or between tendons and bones,to prevent friction between these organs. There is a large bursa at the kneecap and severalaround the joint; others are found at the elbow and the ankle. The bursa in the shoulder issituated near the ball of the upper arm. A bursa may become inflamed due to injury,arthritis, or infection. The inflammation is very painful and is known as bursitis. It is mostcommon in the shoulder and knee. Torn Knee Cartilage. The cartilage pads in the knee joints are frequently torn insports, especially football. They may then become loose and cause pain, swelling andprevents free movement. A new method of treating this injury is a surgical removal of part - 16 -

or all of one or both cartilage pads in the knees. This is usually done by opening a kneejoint. A new method involves using an ARTHROSCOPE, a slim viewing instrument that canbe inserted, along with tiny instruments, through small holes into the joint. Through the miracles of bone surgery, fractured bones can be joined together withpins. Crushed bones are repaired by grafting bone into the destroyed section. In bonebanks, pieces of bones are available for surgery. This bone tissue can serve as aframework until it is absorbed by the body and replaced with new bone.Muscle Problems Have you ever had sore muscles after doing a lot of exercise or after trying to reachfar objects? Have you ever had a charley horse or muscle cramps? These three problemsare quite different from each other. Muscle soreness happens when small tears occur in your muscles. This mayhappen if muscles have not been used for a while. A charley horse is a bruise in whichtears may occur in the muscle. This time, however, the tears cause bleeding from inside themuscle. Bleeding results when small capillaries are broken. Muscle cramps result from asudden and usually strong contraction of muscle. All muscles have nerve cells that connect to them. When a message moving along anerve cell reaches a muscle, the muscle contracts. Without nerve cells, muscles would notbe able to contract and then move body parts. A disease called muscular dystrophy interrupts muscles and nerves acting together.Muscular dystrophy is the slow wasting away of muscle tissue. People with this diseasemay lose the use of some or all of their skeletal muscles. Although the cause of the diseaseis not exactly known, nerve cells leading to muscles are thought to cause the problem. What you will do Self-Test 3.1 1. What is arthritis? 2. What happens to ligaments during a sprain of the ankle? 3. What is muscular dystrophy? Key to answers on page 23. - 17 -

Keeping Bones and Muscles Healthy Have you observed that the parts of your body that are used are big and strong whilethose parts that are not used waste away? This is also true of your bones and muscles.Many of you do not get enough exercise. As a result, muscles grow soft and weak, andbones grow brittle and break easily. If you exercise regularly, you can keep your musclesstrong and healthy. Exercise will also strengthen your bones and joints, so that they areless affected by an injury. What you will do Activity 3.2 Strengthening Abdominal MusclesFollow the directions below and find out the effect on your body. 1. Lie on your back with your knee bent and your hands clasped behind your head. 2. Curl up until half of your body is off the floor. 3. Hold this position, then curl back down. a. Do ten curls first; then gradually increase. b. How did you feel after the exercise. Many types of bone, muscle and joint injuries can be avoided by exercising properlyto strengthen the body. Exercises for strength, endurance, flexibility, and motor control areessential to keep bones and muscles healthy. Good posture means the various parts of thebody are balanced with one another. Good posture is important not only for appearance,but also for overall health. What you will do Activity 3.3Follow the directions below. 1. Tighten your abdominal muscles as though you are about to receive a blow there. 2. Hold them tight for 30 seconds and relax. 3. Repeat several times. You can do this exercise several times during the day, for example, while combingyour hair or just walking down the street. You must be very tired after performing the activities, but think about the benefits yougot from doing them. They surely will help keep your bones and muscles healthy. - 18 -

Let’s Summarize1. The skeletal system protects the vital organs inside the body, serves as attachment for muscles, and produces blood cells.2. The bones, cartilage, ligaments and tendons make up the skeletal system.3. There are 206 bones in an adult human skeleton.4. Bone is a hard living tissue.5. Cartilage is a tough, flexible tissue.6. Ligaments attach one bone to another where two bones connect.7. Tendons are tissues that connect the bone to a muscle.8. The five parts of the human skeleton are the skull, ribcage, backbone, front appendages, and the back appendages.9. Joints connect bones.10. The five types of joints are hinge joint, pivot joint, ball-and-socket joints, gliding joints and the fixed joints.11. There are 600 muscles in the human body.12. Muscles give shape to the body, make movement possible, and protect delicate organs.13. The three kinds of muscles are the skeletal or voluntary muscles, the smooth or involuntary muscles, and the cardiac or the heart muscles. Muscles always act in pairs.14. Skeletal muscles are muscles attached to bones. They can be controlled.15. Smooth or involuntary muscles cannot be controlled.16. Cardiac muscles are involuntary muscles found only in the heart.PosttestMultiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. The system that provides form and support to the body is calleda. digestive c. muscularb. circulatory d. skeletal2. The connective tissue which connects a muscle to a bone is thea. blood c. ligamentb. joint d. tendon3. What system provides the body with movement?a. circulatory c. muscularb. digestive d. skeletal - 19 -

4. What do you call the place where two bones meet?a. cartilage c. jointb. medullary cavity d. periosteum5. What tissue serves as a cushion found at the end of the bones where they meet?a. cartilage c. muscleb. ligament d. tendon6. Which connects a muscle to a bone? c. muscle a. cartilage d. tendon b. ligament7. The joints of the skull do not move. What do you call this kind of joint?a. ball-and-socket c. hingeb. fixed d. sliding8. Which bone protects the heart and lungs?a. cranium c. rib cageb. pelvis d. spinal column9. When our ankle is sprained, which tissue in the joints is stretched or torn?a. cartilage c. periosteumb. ligament d. tendon10. Which of the following statements is NOT true about muscles? a. Muscles work alone to provide movement. b. Cardiac muscles are found only in the heart. c. When a muscles contracts it pulls one bone toward another bone. d. All muscles are connected to bones.11. What two muscles of the arms perform bending or extending actions?a. carpals and phalanges c. biceps and tricepsb. tarsals and phalanges d. deltoid and brachialis12. Which muscles are used to make fast and precise movements?a. cardiac c. voluntaryb. involuntary d. smooth13. Muscle increases in size with use. The statement isa. correct c. sometimes trueb. not correct d. not known14. The most abundant of the three types of muscles in the human body are thea. cardiac c. ligamentsb. involuntary d. voluntary - 20 -

15. A joint that allows movement in all direction is thea. ball-and-socket c. hingeb. gliding d. pivot16. The part of the bone which contains nerves and blood vessels is thea. cartilage c. periosteumb. ligaments d. tendon17. The soft center of a bone is the c. periosteum a. cartilage d. spongy layer b. marrow18. Movements of the arms, head or the fingers can be controlled. The muscles of theseparts area. cardiac c. skeletalb. involuntary d. voluntary19. The mineral used by the body and is a part of all bones isa. calcium c. phosphorusb. carbohydrates d. protein20. Which type of muscles do most digestive organs have in their walls?a. cardiac c skeletal.b. involuntary d. voluntary Key to answers on page 23. Key to AnswersPretest1. b 6. a 11. d 16. d 17. c2. a 7. b 12. a 18. b 19. a3. d 8. a 13. d 20. c4. b 9. a 14. c5. a 10. d 15. cLesson 1Activity 1.1a. Nob. Yes, because the wire gives support. - 21 -

c. Served as supportd. It also bent in different directions.e. Bonesf. Smooth or easy bendingActivity 1.2 Item Tested Bubbles Form with acid? Is calcium present? (Yes or No) (Yes or No)Chalk Yes YesGlass No NoCow bone Yes YesChicken bone Yes YesPigs meat Yes YesWood No No1. When hydrochloric acid was poured, bubbles appeared.2. When hydrochloric acid was poured, no bubbles appeared.3. Cow bone and chicken bone4. Calcium straightens and shape bones.5. No, because it is not a skeleton.Self-Test 1.11. Bone, cartilage, ligaments and tendons2. A connective tissue with a solid matrix, bone is alive and made of cells.3. Cartilage are soft bones.4. Tendons connect muscles to bones.5. Ligaments connect a bone to another bone.6. Cranium, rib cage, backbone, front appendages, back appendages.Lesson 2 Involuntary Voluntary Cardiac / /Activity 2.1 / / / / Actions 1. Yawning / 2. Running 3. Skipping / 4. Breathing / 5. Shivering / 6. Blinking of the eyes 7. Heart beating 8. Digesting food 9. Stretching arms 10. Playing piano - 22 -

Lesson 3Self-Test 3.11. Arthritis is a disease of the joints of the bones.2. The ligaments are stretched.3. Muscular Dystrophy is a slow wasting away of the muscle tissue. The muscle becomes small.Posttest1. d 6. d 11. c 16. c2. d 7. b 12. c 17. b3. c 8. c 13. a 18. d4. c 9. b 14. d 19. a5. a 10.d 15. a 20. bReferencesBooks:Daniel, L. (1994). Life science. Westerville, OH: Merill Publishing Co.,Mcmillan/McGraw- Hill.Grabowski, T. (2003). Principles of anatomy and physiology. N.Y.: John Wiley and Sons, Inc.Holo, W. (1984). Human anatomy and physiology. (3rd Ed.) Iowa: W. C. Brown Publishers. Dubuque.Hopson, J.L. & Wessells, N.K. (1990). Essentials of biology. USA: McGraw-Hill Publishing Company.Kaskel, A., Hummer, P.J. & Daniel, L. (1981). Biology on everyday experience. USA: Merill Publishing Co.Mariele, E.N. (1998). Essentials of human anatomy and physiology. (3rd Ed.) New York, USA: Addison-Wesley Longman, Inc.Payne, H. (1995). Understanding your health. St Louis, Missouiri: Mosby Publishing Company.Pikering, W.H. (2000). Complete biology. New York: Oxford University Press Wong. - 23 -

Electronic Sources:Retrieved January 10, 2005 htttp//www4.tpgi.com.au/users/amcgann/body/.htmlRetrieved January 10, 2005 from http//www.innerbody.comRetrieved January 10, 2005 from http/www.bartleby.comRetrieved January 10, 2005 from http//www.sirinet.ml/~jgjohnso/biologyII. - 24 -

Module 11 Energy Producing and Distributing Systems What this module is about You have just finished the module on the musculo-skeletal system. Did you discoverconcepts you did not know before? As the human body is a complex machine, there aremore to learn about it. Let’s take a tour of the energy producing and distributing system. This module has the following lessons:  Lesson 1 – Digestive System  Lesson 2 – Respiratory System  Lesson 3 – Circulatory System What you are expected to learn After going through this module, you are expected to: 1. Explain why digestion of food is important. 2. Name the parts of the human digestive system and explain its role. 3. Explain the role of the human digestive system. 4. Describe how some accessory organs and glands help the body in the digestive process. 5. Define respiration and its two phases. 6. Trace the pathway of oxygen and carbon dioxide through the human respiratory system. 7. Draw the parts of the respiratory system. 8. Label the parts of the respiratory system. 9. Identify the functions of the circulatory system. 10. Identify the parts of the circulatory system. 11. Describe the parts of the circulatory system. 12. Illustrate the human heart. 13. Show the importance of the human heart. 14. Describe how a human heart works. 15. Explain the importance of exercise in blood circulation. 16. Be aware of the precautionary measures to take in order to maintain a normal and healthy heart.

How to learn from this module In order to achieve the objectives of this module, you have to remember thefollowing: 1. Read and follow instructions carefully. 2. Answer the pre test. 3. Take down notes and record points for clarification. 4. Take the posttest and check your answers against the answer key at the end of the module. 5. Try to get at least 75% level of proficiency in each test. 6. Work quietly and honestly. What to do before (Pretest)I. Multiple Choice. Choose the letter of the correct answer. Write the chosen letter on aseparate sheet of paper.1. What is the process of changing food into a simpler substance for use by the cells?a. chewing c. eatingb. digestion d. excretion2. What do you call the process of changing food into a simpler substance with the help ofenzymes?a. chemical digestion c. masticationb. churning d. mechanical digestion3. Where does the final digestion of food take place?a. large intestine c. mouthb. liver d. small intestine4. Normally, an average meal will stay in the stomach for about how many hours?a. 2 to 4 c. 4 to 5b. 3 to 4 d. 5 to 65. What is the product of digestion in the mouth?a. bile c. chymeb. bolus d. feces -2-

6. What do you call the wave -like contraction in the walls of the digestive tract?a. chewing c. masticatingb. digesting d. peristalsis7. Roughage foods are good for the digestive system because these helpa. prevent diarrhea c. regulate body temperatureb. prevent ulcers d. regulate bowel movement8. Which system is responsible for the exchange of oxygen and carbon dioxide betweenthe air and the cells?a. circulatory c. excretoryb. digestive d. respiratory9. Which organ serves to filter and warm the air entering it?a. air sac c. diaphragmb. bronchus d. nasal cavity10. Where does exchange of gases take place?a. alveoli c. bronchiolesb. bronchi d. diaphragm11. The chemical process in which oxygen and carbon dioxide are exchanged between theoutside air and the cells is calleda. breathing c. exhalingb. inhaling d. respiration12. The life support system that feeds the cells with food and oxygen is thea. circulatory c. excretoryb. digestive d. respiratory13. Which organ is NOT a part of the circulatory system?a. blood c. esophagusb. blood vessel d. heart14. Which organ is referred to as the living pump?a. heart c. lungb. liver d. stomach15. All of the following carry blood to and from all parts of the body EXCEPT:a. arteries c. large intestinesb. capillaries d. veins -3-

II. Write each organ in the column of the system to which it belongs.nose blood stomachair sacs heart capillariesliver diaphragm mouthblood vessels esophagus arteriesgall bladder bronchi small intestinetrachea larynx veinsDigestive Circulatory RespiratoryIII. Identification: Identify the following systems A Figure 4. Respiration Processhttp//www4.tgpi.com.au/users/amcgann/body/respiratory.html -4-

B Figure 5. The Heart http//www4.tgpi.com.au/users/amcgann/body/circulatory.htmlC Figure 1. The Digestive System http//www4.tgpi.com.au/users.amcgann/body/digestive.html - 5 - Key to answers on page 26.

Lesson 1. The Digestive System Why do we eat? Is eating necessary to stay alive? We need food to provide energyfor moving about. Food also supplies the raw materials needed for growth and repair ofbody parts. Body cells need food for energy, growth and repair. However, when food is eaten, it is not in a form that can be used by cells in the body. Food must be broken down into a form that cells can use. The body changes food into a usable form by means of a group of organs known as the digestive system.http//www.tgpi.com.au/users/amcgann/foodpyramid.html If you were told that your digestive system is like a factory, would you believe it? It is true. In a factory, raw materials are brought in and transported to different places in the factory. As the raw materials move through the factory, they change in various ways. Finally, they come out of the factory as several new products. Your digestive system works in a similar way. Food enters the digestive systemthrough your mouth. Food is the raw material. Once inside your body, it moves through thedifferent organs of your digestive system. It is where the food is changed. The function of the digestive system is digestion. Digestion is the breakdown oforganic compounds into their simple forms for use by the cells. Digestion is the life supportjob of the digestive system. The digestive system breaks down food in two ways:mechanically and chemically. Organs of the digestive system that chew, tear, churn, squeeze and grind food helpin mechanical digestion. On the other hand, the organs that make and use chemicals tobreak apart the food and reduce it to liquid help in chemical digestion. There are two groups of organs in the digestive system. One group makes up theGASTROINTESTINAL TRACT, a food tube that is open at each end and includes themouth, esophagus, stomach, and intestine. The other group of organs makes and stores the chemicals that chemically breakdown the food. These are the liver, pancreas, gall bladder, and salivary glands. -6-

Let’s take a trip through the human digestive system to see how it works. To make ita little more interesting, try to imagine what happens to a hamburger when eaten.Remember that ground meat is mostly protein, mayonnaise is mostly fat, and the bun ismostly carbohydrate. By the way, the trip takes about 18-20 hours. Look at the figure on the next page. Trace the pathway of the hamburger that youate in your body. Get set, go! Humans and many other animals havea digestive system with two openings. Foodenters the system by way of the mouth. Mouth. The food tube, nine meterslong, begins at the mouth. The teethmechanically chew, chop and break the foodapart. The breaking and gliding are physicalchanges. The SALIVARY GLANDS produce achemical that starts the breakdown ofcarbohydrates. The product of digestion in themouth is the bolus. Food moves from themouth to the esophagus when you swallow. Esophagus. The esophagus is a tubethat connects the mouth to the stomach.Muscles of the esophagus push and transportfoods and liquids to the stomach. Stomach. The stomach is a bag-like Figure 1. The Digestive Systemmuscular organ. The function of the stomachis to grind the food and mix it with the http//www4.tpgi.com.au/users/amcgann/digestive juices. It can hold about one liter of body/digestive.htmlliquid and food. The product of digestion inthe stomach is chyme. The stomach hasspecial cells in its walls that make gastric juice.Gastric juice begins the chemical breakdownof proteins. After about four hours, thestomach pushes food into the small intestines.Do you know?That the pH of the stomach is 2? It is more than enough toburn your dress!-7-

Small Intestine. The small intestine is where most of the food is chemicallydigested. The small intestine itself makes several digestive juices. Some of thesechemicals digest proteins into amino acids. Others digest carbohydrates into simple sugars. Do you know? That you can live without your stomach but never without the whole small intestine!Before describing what the small intestine does we must take a short detour. Let us pass bythe three organs that are part of the digestive system. These organs are the liver, pancreasand gall bladder. Liver. The liver is the largest organ in the body. It has a mass of about twokilograms. The liver makes bile, a green liquid that breaks up large fat droplets into small fatdroplets and stores it in the gall bladder. When needed, bile enters the small intestine andaids in the digestion of fat. If bile is not needed, it is delivered to the gall bladder. Pancreas. The pancreas is a small organ that makes three different kinds ofenzymes and is found below the stomach. It makes about half of the liters of digestivejuices made each day. These juices aid in the digestion of all three organic compounds. Gall Bladder. The gall bladder is a small pear shape sac that can hold about 50ml ofbile. It stores the bile until it is needed by the small intestine to emulsify fats. Large Intestine. The job of the large intestine is to remove the useful liquids fromthe undigested food. The undigested food, called FECES, is solidified and pushed out tothe anus. If the large intestine did not return two liters of liquids to the body a day, a personcould die from lack of water. Aside from water, this organ also reabsorbs salt for further useby the body. The small intestine receives digestive juices from the LIVER and PANCREAS. Theliver contributes BILE, which digests fat. But, it is the small intestine that makes andreceives many digestive chemicals that complete the digestion of food. Our entire trip through the digestive system took about 20 hours. Look at the figure 1again. It shows how the entire digestive system looks from one end to the other. -8-

What you will doActivity 1.1This activity will help you estimate the length of the digestive system.Materials needed:yarns of different colors (blue, green, red, yellow)scissorsrulerProcedure:1. Cut pieces of yarns according to the measurements provided below, but have an extra length for each piece for tying.2. Use different colors of yarn to represent the different organs.3. After the yarns have been cut, tie the pieces together and measure again. Blue … 25 cm Green … 20 cm Red … 700 cm Yellow … 150 cm 895 cmAnswer the following questions:1. What is the longest measurement? What does this represent?2. What is the shortest measurement? What does this represent?3. What is the second to the shortest measurement? What does this represent?4. How will you compare the longest yarn and the 2nd to the longest yarn?5. What do you think is the reason why food stays in the body for 8 hours? Key to answers on page 26. -9-

What you will doSelf-Test 1.1Rearrange the parts of the digestive system in the correct sequence. Write the letters of thecorrect answer on the blank.Digestion Processa. small intestine 1.________b. anus 2.________c. stomach 3.________d. mouth 4.________e. large intestine 5.________f. esophagus 6.________g. rectum 7.________ Key to answers on page 26.How Nutrients Get Into the Blood Nutrients get into the blood system through the small intestine. The inside of thesmall intestine is not smooth like a garden hose. Instead, the inside of the small intestine islined with millions of tiny hair-like projections called VILLI. (singular: villus) Villi increase the surface area of the microvillismall intestine to about five times than thatof a smooth surface. As the food moves epithelial cellslowly between, over and around the villi, capillary (blood)nutrients are absorbed into the bloodstream lacteal (lymph)inside each villus. duodenal gland The wall of each villus is only onecell thick. Digested foods can easily pass Figure 2. The Villithrough these layers of cell. Examine thecross section of the small intestine on theright and notice the finger–like folds calledthe rugae. These are lined with hair-likeprojections called the villi. - 10 -

What you will do Activity 1.2Procedure: Draw two circles – Circle A and Circle B as shown below AB 1. Place a piece of string around the inside of circle A. 2. Cut off any extra string so it fits exactly. 3. Measure the string in centimeters. 4. Place a piece of string around the inside of circle B. 5. Cut off any extra string so it fits exactly. 6. Measure the string in centimeters. Which is longer circle A or circle B? You should have discovered that the inside ofcircle B is three times longer than the inside of circle A. The same kind of thing happens inthe small intestines. Villi make the surface larger. The larger surface means digested foodis absorbed better.What you will doSelf Test 1.21. Where are most of the food nutrients absorbed?2. Describe the inside of the small intestine.3. How do the villi increase absorption?4. What is the function of the digestive system?5. Key to answers on page 27. - 11 -

Lesson 2. Respiratory SystemThe Exchange of Gases Do you know that you can survive for several days without water and survive for amonth without food, but you cannot survive for more than five minutes without oxygen? Oxygen is the part of the air that we breathe. Air is a mixture of different gases. Theair you breathe is made up of Oxygen … 21.0% Nitrogen … 78.1% Carbon Dioxide … 0.03% Other gases … 0.87% Life depends on breathing because the cells of the body need oxygen. You breathein to bring fresh air into the lungs. The lungs must separate the oxygen from the air. Thenyou breathe out to get rid of the carbon dioxide that the body does not need. Breathing is a mechanical process. It is a process of pumping air into and out of thelungs. Breathing is done by a group of organs that make up the RESPIRATORY SYSTEM(Figure 3). The function of the respiratory system is to exchange oxygen and carbondioxide between the air and the cells. The respiratory organs filter particles from the incoming air. They help control thetemperature and water content of air. They also aid in producing the sounds used in speechand play important roles in the sense of smell and the regulation of pH. Now, let us take a tour of our respiratory system. The following are the parts andtheir functions.  Nose. The function of the nose is to filter and warm the entering air with the help of the cilia (hairs inside it).  Pharynx. The pharynx is commonly called the throat. It connects the nose with the windpipe.  Trachea. The trachea is commonly called the windpipe.  Bronchus. The trachea branches into two tubes, the BRONCHI, inside the lungs. Each bronchus continues to branch and rebranch until it is very small. Each tube finally ends in a tiny air sac called an ALVEOLUS (plural: alveoli).  Lungs. The lungs are two up-side-down, cone-shaped organs inside the chest. - 12 -

The lungs are really two bags full of thousands and thousands of alveoli. It is at the alveoli inside the lungs that gases are exchanged. Diaphragm. The diaphragm is a large muscle that lies flat at the bottom of the chest cavity. The diaphragm aids in breathing by moving up and down. Rib Muscles. The lungs are protected in the chest cavity by a set of rib bones. The tissues between the rib bones are the rib muscles. These muscles are the meat you eat on a sparerib. The rib muscles move the rib bones and cause the chest cavity to enlarge and contract. The rib muscles work together with the diaphragm to aid breathing. Figure 3 Respiratory System http//www.sirinet.ml/~jgjohnso/ biologyII.html - 13 -

What you will doActivity 2.1A. Demonstration of breathingProcedure:a. Close your mouth, then press your noseb. Do it for a few seconds or for as long as you can hold breathing.Answer the following questions:a. How did you feel as you press your nose with your mouth closed? Why?b. What happens when the air cannot enter the body?c. What air do you inhale? What air do you exhale?B. Respiration ProcessCreate a mental picture of the respiratory system. Using the words in column A writethe correct sequence in column B.Column A Column Bair sacs 1.________bronchioles 2.________nose 3.________trachea 4.________pharynx 5.________bronchi 6.________larynx 7.________ Key to answers on page 27. When you breathe in or inhale, the diaphragm contracts. Inhaling moves thediaphragm down and makes the size of the chest cavity larger. At the same time, the ribsmove up and increase the size of the chest cavity. There is now more space and less airpressure inside the lungs. Air pushes in from the outside where there is a higher airpressure. It pushes into the lungs where there is a lower air pressure. When you breathe out, or exhale, the diaphragm relaxes. The diaphragm and ribsreturn to their original place. The chest cavity returns to its original size. There is now lessspace and more air pressure inside the lungs. It pushes the air to the outside where there isa lower air pressure. - 14 -

Remember, in the process of breathing 1. the size of the chest cavity changes when the diaphragm and rib muscle expand and contract. 2. air pressure changes when there is a change in the size of the chest cavity. 3. air moves in and out of the lungs when there is a change in the air pressure inside the chest cavity. Figure 4. Respiration Process http//www4.tpgi.com.au/users/amcgann/ body/ respiratory.htm What you will do Self-Test 2.1 1. What change causes the air to move into and out of the lungs? 2. What is the function of the respiratory system? Key to answers on page 27.The Process of Respiration Breathing and respiration are two different processes. BREATHING is a mechanicalprocess of pumping air into and out of the lungs. The lungs are like two bags turned insideout, inside the body. The gases in the lungs must get to the cell, and the waste gases in thecells must get to the lungs. For this to happen, a chemical process is needed. The chemical process in which oxygen and carbon dioxide are exchanged betweenthe outside air and the cells is called RESPIRATION. - 15 -

Respiration takes place in two stages. External respiration is the exchange ofgases between the air and the blood. Internal respiration is the exchange of gasesbetween the blood and the cells. External respiration takes place at the alveoli. The surfaces of the alveoli arecovered with a network of tiny blood vessels that are called CAPILLARIES. The walls of the alveoli are one cell thick. The walls of the capillaries are also onecell thick. By diffusion, oxygen passes from the alveoli in the lungs into the capillariesacross two rows of cells. At the same time, carbon dioxide passes from the capillaries tothe alveoli across the same two rows of cells.What you will doActivity 2.3 Experimental data and statistics show that 90 percent of all lung cancer cases are theresult of smoking. Write an advertising campaign to urge people especially the young(adolescents), to avoid smoking. Include information on the effect of smoking on therespiratory system.What you will doSelf-Test 2.2Study the illustration of the respiratory system very well. Identify the parts as numbered 2 7Key to answers on page 27. 6 4{1 8 3 5 - 16 -

Lesson 3. The Circulatory System The circulatory system is the life support system that feeds your cells with food andoxygen. It also takes away the waste products. The circulatory system is like a network ofhighways, streets and alleys connecting all the cells together into a community. In turn thecommunity of cells keeps the body alive. There are two divisions of this system, thelymphatic, which helps to return tissue fluid to the blood, and the blood division, which is aclosed circuit. There are three main parts to the circulatory system. These are the heart, the bloodvessels and the blood. THE CIRCULATORY SYSTEM Parts Function Heart ………pumps the blood Blood Vessels ……... carry the blood Arteries ……….carries the materials Veins Capillaries BloodThe Human Heart Look at your fist. Note itssize. Your HEART (Figure 5) is abundle of muscles about the size ofyour fist. The heart is shaped like acone. It is located in the center ofyour chest between the lungs. It istilted to one side and pointsdownward to the left. Your heart is a living pump.It is really two pumps in one, a pumpon the left side and a pump on theright side. Each side is dividedacross into two chambers. The topchamber is called the ATRIUM(plural: atria). The bottom chamberis called the VENTRICLE. Bothsides of the heart are divided in thesame way. Figure 5. The Heart http//www4.tpgi.com.au/users/amcgann/body/circulatory.html - 17 -

There is a VALVE between each atrium and ventricle to prevent the blood fromflowing backwards. The valves are like one-way doors that keep the blood moving in onlyone direction. What you will do Self-Test 3.1 1. What is the size, shape and location of the heart? 2. Name the four chambers of the heart. 3. What is the function of the valves? Key to answers on page 27.How the Heart Works The function of the circulatory system is to carry materials to and from all parts of thebody. The power for the circulatory system comes from the muscular action of the heart.The heart does its work by contracting and relaxing. All of the muscle tissues of the heart do not contract at the same time. Different partsof the heart contract at different times. When the top contracts, the bottom relaxes. Whenthe bottom contracts, the top relaxes. When a chamber contracts, it becomes smaller andthe blood inside gets squeezed or pumped out. To have a better understanding of how theheart works, do this simple activity.What you will doActivity 3.1 The Pumping on the HeartMaterials: Plastic bottle (preferably white) Water DyeProcedure:1. Fill the plastic bottle with colored water.2. Observe the content closely. No liquid is pushed out. The same is true with the heart. If the heart muscles don’t squeeze together, no blood is pumped.3. Squeeze the bottle with both hands and observe what happens. When the heart muscles squeeze together, blood is pumped. - 18 -

Answer the following questions: 1. What is the function of the circulatory system? _________________________________________________________________ 2. Name the chambers through which blood flows in the right order. _________________________________________________________________ 3. What does the blood pick up? _________________________________________________________________ 4. What kind of blood goes to the body? _________________________________________________________________ Key to answers on page 28. There are four valves in the heart. The valves are one of the most important parts ofthe heart. When the atria contract, the tricuspid (right) and bicuspid valve (left) open. Whenthe ventricles contract, the pulmonary and aortic valves open. When these two phases arerepeated, you have one heartbeat cycle. The two phases of the heartbeat cycle can be heard. “Lub-dub” is the sound yourheart makes. The heart beat sound is caused by the contraction of the muscles and theslamming shut of the valves. In the “lub” phase the ventricles contract and the tricuspid andbicuspid valves close. In the “dub” phase, the pulmonary and aortic valves close. A normalheart repeats the “lub- dub” sound over and over again in perfect rhythm. What you will do Activity 3.2 Tracing the Flow of Blood through the Heart The path the blood takes through the heart is listed below. Write the letter for eachstep in the proper place in drawing of the heart. a. Blood returning from the body travels through a blood vessel connected to the heart. b. The blood enters the right atrium. c. After the right atrium fills, the atria contract. This pushes the blood past a one- way valve. d. The blood fills the right ventricle. e. The ventricles contract and push the blood which passes another valve into a blood vessel. - 19 -

f. This blood vessel goes to the lungs where the blood picks up oxygen.g. Blood from the lung travels through a blood vessel to the heart.h. The blood enters the left atrium.i. After the left atrium is filled, it contracts. This pushes the blood to a one-way valve.j. The blood fills the left ventricle.k. The ventricles contract and push the blood to a valve into a blood vessel.l. This blood, rich in oxygen, goes to the body. http://www4.tpgi.com.au/users/amcgann/body/circulatory.html Key to answers on page 28.The Blood Vessels The circulatory system is a closedsystem. This means that the blood staysinside the heart and a set of tubes as itcirculates. Your blood moves through your bodyin tubes called VESSELS. There are threekinds of blood vessels that make up thecirculatory system: ARTERIES, VEINS,and CAPILLARIES. The arteries carry blood away from Figure 6. Flow of Bloodthe heart. The veins carry blood towardsthe heart. The capillaries are very small http//www4.tpgi.com.au/users/amcgann/body/tubes that connect the arteries to the veins. circulatory.html The blood vessels form an intricate transportation network to service every cell.Transportation is the function of the circulatory system. The human body has 100,000kilometers of blood vessels. If laid end to end, a person’s blood vessels would circle theearth twice! - 20 -

Arteries. Arteries have thick, muscular walls. They are elastic and expand everytime the ventricles contract. The force of the heart pumping keeps the blood movingthrough the arteries. Arteries carry blood away from the heart. The blood in the arteries is bright redbecause it contains much oxygen. The large artery is the AORTA. This is the first artery leaving the heart to the body.The arteries branch into smaller and smaller vessels, which end at the capillaries. Veins. Veins have muscular walls too, but they are thinner than the walls of thearteries. There are one-way valves inside the veins to prevent the blood from flowingbackwards. Blood is moved along when you move your muscles. This squeezes the bloodinside the veins and pushes the blood towards the heart. Veins carry blood to the heart. The blood in the veins is blue in color because it lacksoxygen. You can see some of your veins because they are right under the surface of theskin. The veins begin at the capillaries and join into larger veins until the largest veinempties into the heart. Capillaries. Capillaries are tinyvessels that connect arteries to veins. Thecapillaries are so small that the red bloodcells must pass through them in single file.Also, the walls of the capillaries are only one-cell thick. The work of the circulatory systemtakes place at the capillaries. It is here thatthe exchange of materials between the bloodand the cells takes place. At the capillaries,food and oxygen pass from the blood to thecells. Also, carbon dioxide and wasteproducts pass from the cells to the blood. The circulatory system is really twoseparate systems. One part of the systempumps blood to the lungs. Another part ofthe system pumps blood to the body. Bloodmust go to the lungs to pick up oxygen beforeit can go to the body. Figure 7. The Circulatory System http/www.innerbody.com/htm/body- 21 -

What you will do Self-Test 3.21. What kind of system is the circulatory system? Explain.2. Name the kinds of blood vessels.3. What is the purpose of the blood vessels?4. How does blood move in the arteries?5. How does blood move in the veins?6. What and where are the capillaries?7. What vital function takes place at the capillaries? Key to answers on page 28.What you will doActivity 3.3 Circulation process Rearrange the flow of blood to the heart in the correct sequence. Write the letter ofthe correct answer in the blank.A. Pulmonary veins 1. __________B. Tricuspid valve 2. __________C. Superior and inferior vena cava 3. __________D. Aorta 4. __________E. Lungs 5. __________F. Pulmonary artery 6. __________G. Bicuspid / Mitral valve 7. __________H. Right auricle 8. __________I. Left ventricle 9. __________J. Right ventricle 10. __________K. Left auricle 11. __________ Key to answers on page 28. The blood is a fluid that carries most of the materials necessary for life. The bloodhas two different parts. The nonliving, liquid part is called PLASMA. It is a yellowish fluidthat makes up 55 percent of your blood. The remaining 45 percent is made up of threekinds of cells: red blood cells, white blood cells and platelets. Plasma is the fluid part of the blood in which the blood cells coat is a yellowishsubstance composed of 92% water and 8% of dissolved nutrients, mineral salts, antibodiesand hormones. - 22 -

The proteins present in the plasma are: It regulates 1. Albumin – helps in keeping the blood pressure normal. the amount of water in the plasma. 2. Globulin – contains antibodies. 3. Chemical Substances – effective against specific diseases 4. Fibrinogen – works with platelets in the clotting process. Red Blood Cells (RBC) are also called erythrocytes.They are the most numerous cells in the blood. Each liter ofblood contains 4.5 to 6 trillion red blood cells. The maincomponent of red blood cells is the pigment known ashemoglobin. Hemoglobin in the RBC binds and carriesoxygen. White Blood Cells (WBC) are larger and lessnumerous than RBC (red blood cells). WBC (white bloodcells), also called leukocytes, contain nuclei and other typesof organelles. WBC may circulate in the blood for weeksbefore leaving the blood and entering other tissues. WBChelp defend the body against infection.Let’s Summarize1. Digestion is the process that changes food so that it can be used by the body.2. Cells need food for growth and energy.3. The digestive system breaks down food mechanically and chemically.4. The digestive system must digest the food, extract the nutrients and dispose the waste.5. The salivary glands produce a chemical that begins the digestion of carbohydrates.6. The stomach grinds the food and mixes it with the gastric juice.7. The liver and pancreas produce digestive juices that aid digestion in the small intestine.8. The small intestine makes and receives many digestive chemicals that complete digestion of food.9. Life depends on breathing because the cells need oxygen.10. The nose filters and warms the entering air.11. Air enters the nose or mouth, goes down the trachea and bronchus, and ends in the alveoli.12. Gases are exchanged at the alveoli.13. The diaphragm and rib muscles work together to expand and contract the size of the chest cavity. - 23 -

14. Breathing is the mechanical process of pumping air into and out of the lungs.15. The air that we take is oxygen and the air that we breathe out is carbon dioxide.16. The circulatory system transports materials to and from all parts of the body.17. The main parts of the circulatory system are the heart, blood vessels and blood.18. The heart is a pumping organ.19. The heart is a bundle of muscles.20. The heart is two hearts in one, a left heart with two chambers and a right heart with two chambers.21. The left heart pumps blood to the lungs, and the right heart pumps blood to the body.22. The two phase of respiration are: inhalation, the taking in of oxygen; and exhalation, the removal of carbon dioxide from the lungs.23. The different parts of the respiratory system are: nose, pharynx, larynx, trachea, bronchi, bronchioles, bronchial tubes and air sacs.24. The circulatory system is made up of the heart, the blood vessels and the blood.25. Physical exercise makes your heart stronger because your heart beats faster. This enables the blood to circulate efficiently. Thus supplying oxygen to the tissues and forcing out carbon dioxide.26. Eating a balance diet, not smoking and exercise can help maintain a normal and healthy heart.PosttestI. Multiple Choice. Choose the letter of the correct answer. Write the chosen letter on aseparate sheet of paper.1. The chemical process in which oxygen and carbon dioxide are exchanged between theoutside air and the cells is calledm. breathing c. exhalingn. inhaling d. respiration2. The life support system that feeds the cells with food and oxygen is theo. circulatory c. excretoryp. digestive d. respiratory3. Which organ is NOT a part of the circulatory system?q. blood c. esophagusr. blood vessel d. heart4. Which organ is referred to as the living pump?s. heart c. lungt. liver d. stomach - 24 -

5. All of the following carry blood to and from all parts of the body EXCEPT:u. arteries c. large intestinesv. capillaries d. veins6. What is the process of changing food into a simpler substance for use by the cells?w. chewing c. eatingx. digestion d. excretion7. What do you call the process of changing food into a simpler substance with the help ofenzymes?y. chemical digestion c. masticationz. churning d. mechanical digestion8. Where does the final digestion of food take place?aa. large intestine c. mouthbb. liver d. small intestine9. Normally, an average meal will stay in the stomach for about how many hours?cc. 2 to 4 c. 4 to 5dd. 3 to 4 d. 5 to 610. What is the product of digestion in the mouth?ee. bile c. chymeff. bolus d. feces11. What do you call the wave -like contraction in the walls of the digestive tract?gg. chewing c. masticatinghh. digesting d. peristalsis12. Roughage foods are good for the digestive system because these helpii. prevent diarrhea c. regulate body temperaturejj. prevent ulcers d. regulate bowel movement13. Which system is responsible for the exchange of oxygen and carbon dioxide betweenthe air and the cells?kk. circulatory c. excretoryll. digestive d. respiratory14. Which organ serves to filter and warm the air entering it?mm. air sac c. diaphragmnn. bronchus d. nasal cavity15. Where does exchange of gases take place?oo. alveoli c. bronchiolespp. bronchi d. diaphragm Key to answers on page 29. - 25 -