EVS Organ Systems PDF

SR 1 Organ Systems Let's Connect Back In the previous classes, you learned alot abOut the different organs present in your body. An of your body that has a particular function. For example, your hands help you hold and pick uporg...

SR 1 Organ Systems Let's Connect Back In the previous classes, you learned alot abOut the different organs present in your body. An of your body that has a particular function. For example, your hands help you hold and pick uporgan thinis aapar The parts of your body that you can see andtouch are called external organs. The head, neck, and sense organs such as the eyes, ears, and nose are some external organs present in your body Can you see or touch all the organs in your body? No, not all organs in the body can be seen or ,arms, legs, The organs that you cannot see or touch as they are inside your body are called internal organs. touched. Look at the internal l organs shown in the image given below. Can you identify them? Complete the the internal organs by filling in the missing letters. Next, match each organ to its function. names of Internal Organ Function Bn Pumps blood to all parts of the body Digests the food that we eat Give oxygen to the body and remove carbon dioxide Controls all other parts of somh the body Every organ in the body performs a particular function. Different organs work together in groups, just ike a team, to perform major functions in the body. In this unit, you will learn how different organs in your body work together to perform various functions. Let's Think You have already learned about the different organs of the human body. Do you want to know how these organs work together in groups to keep our body healthy? On WS 1, write two questions you have about organs working together in groups. VLEAD 10  SR 2 Organ Systems Organ Systems inOur Body You knowthattevery organ in the body. to perform major functions in the body performs Agroup ofaparticular function.together organs working perform work to organs Different together a major in groups function in the body is Called an organ system. There are many oroan healthy. Seven of these organ systems are given systems in our body that work Togeuien below. Let us learn aboUt ne Digestive system: The digestive system turns the food that we eat into simple nutrients. These nutrients helo the body in obtaining energy and to grow. Circulatory system: The circulatory system transports nutrients and oxygen through the blood to the entire body. Respiratory system: The respiratory system brings oxygen into the body and removes carbon dioxide from the body. Excretory system: The excretory system removes waste from the body. Skeletal system: The skeletal system gives shape to our body. It provides a structure to support the body and protects the internal organs. Muscular system: The muscular system works closely with the skeletal system and helps our body move. Nervous system: The nervous system controls and monitors all other organ systems in the body. It makes sure that every organ system is doing its job properly. Let's Think All these organ systerhS are present in every human body! You knowthat we get the energy to do different They work in harmony with activities from the food we eat. But do you know each other to keep our body how many organ systems work together to give us energy from the fo0d we eat? healthy. Look at the organ systems above and put a / Now, can you go back to SR 1 against those that you think help give us energy. and guess the organ systems towhich those organs belong? Do you think you got it right? Read on to find out. EAD 11 SR 3 Organ Systems Digestive System Keywords I'm so hungry that my stomach rumbling: making alow is rumbling. SOund continuous Have you ever heard a rumbling sound from your stomach when you are The rumbling sound is your body's way of telling you that your stomach and needs food. hungernnyphy is Food is important for our body. It provides us with the energy to do different activities, helps our and protects us from diseases. But the foodthat we eat cannot be used directly by our body. Whatbody grow, tofood inside our body so that it becomes usable? Where does the food go after we eat it? Let us look at the journey of food in our body. happens The food that we eat is broken down into smaller pieces called nutrients, which our body can use h process of breaking down food into nutrients is called digestion. The organ system that helps us naro the function of digestion is called the digestive system. Parts of the Digestive System The main parts of the digestive system are given below. As you read, use your index finger to that food takes in the digestive system. trace the path Mouth: It is an opening at the start of the digestive system. Oesophagus (say ee-saw-fyh-gus) or food pipe: It is a hollow tube that connects the mouth and the stomach. Stomach: It is a muscular sac-like organ. Food that passes through the oesophagus falls into the stomach. Small intestine: It is a long, thin, coiled tube-like structure. Food from the stomach passes into the small intestine. Large intestine: It is a shorter and wider tube like structure that receives material from the small intestine. Anus: It is an opening at the end of the digestive system. Do you know what happens to food in each part of the digestive system? Let us find out! 12 NLEAD  Organ Systems SR 4 Process of Digestion When we take a bite of food in our mouth, the process of digestion begins. Our mouth has teeth, tongue, and saliva that help in the digestion of food. Teeth help us bite and The salivary glands are present chew food. Chewing inside the mouth. They produce breaks down food into a watery substance called saliva. smaller pieces. The saliva moistens the food and starts the process of digestion. So, when we eat food, the process of digestion begins in the mouth. The tongue helps in chewing, mixing, and Keywords swallowing food. moistens: makes something slightly wet temporary: lasting only for a short time Types of Teeth Human beings have two sets of teeth: temporary and permanent. The first tooth appears when a baby turns six months old. By the age of three, a baby set of teeth is called temporary or milk teeth. has 20 teeth. This first When a child is around six years old, the milk teeth begin to fall out. A new set of teeth milk teeth. These are called permanent teeth. An adult human being has up to 32 grows in place of the permanent teeth. Stand in front of the mirror and observe your teeth carefully. Do all your teeth look different? We have teeth of different shapes and sizes. Some are pointed, while some aretheflat.same oris are they Qur teeth have to perform different functions. Let us learn about the types of teeth. This because Incisors Canines There are eight incisors There are four canines four at the top and two at the top and four at the bottom. two at the bottom. They help in biting They help in tearing food. food. Premolars Molars There are eight There are up to twelve premolars at the back molars - six at the top of our mouth - four at and six at the bottom. the top and four at the bottom. They help in grinding and crushing food. They help in tearing and crushing food. Activity Corner Use white clay to make models of the different types of teeth. Use toothpicks and sticky notes to label the teeth. LEAD 13 SR 5 Organ Systems We know that the digestion of food beoins in the mouth. The mouth prepares the food for the stomach. Let us see what happens to the food once it leaves the mouth. Keywords churned: moved strength with a ot We take in food through our mouth. The teeth, and tongue help in crushing and moistening the smaller pieces. Digestion of food begins in the foog s aliva mouth. The partly digested food passesthroughtthe to reach the stomach. oesophagus Inthe stomach, the food is churned, mixed with digestThiive juices, and digested further into a liquíd mixture. liquid mixture is emptied into the small intestine. The food is completely digested into nutrients in the small intestine. From the small intestine, the nutrients are absorbed into the blood. BIlood carries the nutrients to different parts of our body. Some parts of the food cannot be digested by our body. This undigested fo0d is passed to the large intestine. Here, water is absorbed from the undigested fo0d, and solid waste called faeces or stool is formed. The faeces or stool formed in the large intestine is removed from the body through the anus. D Scan me Activity Corner Use clay of different colours to make a model of the digestive system. Use white chart paper to give abase to this model. for an activity Use sticky notes and toothpicks to label the different parts of the digestive on the digestive system. system. 14 LEAD  AATHVIkA-A SR 6 Organ Systems Maintaining Healthy a The digestive system breaks Digestive System down the fo0d we eat. However, sometimes, when we do not eat on time or if we eata lot of unhealthy food, our digestive system is affected. We may even fall ill. Let us learn about some illnesses of the digestive system. Loose Motions Constipation When we get loose motions, our stool becomes watery and our When we do not pass stool for a hurts. This happens if the foodstomach number of days, it is called constipation. we eat Constipation can cause headaches has germs. This c£n happen if we do not wash our hands before and pain in the intestines. It mostly eating, if We eat unhealthy food from outside, Occurs if we do not consume enough or water, fruits, and vegetables as part of ifwe eat stale food. Our diet. ls there a way to avOid illnesses of the digestive system? Yes! We can practise the following good habits to keep our digestive system healthy. Follow these good habits to prevent loose motions. Follow these good habits to prevent constipation. Wash your hands before eating. Eat slowly and chew food properly. Eat fresh, clean, and well-cooked Drink plenty of water. food. Eat healthy food. Eat lots of fruits Avoid eating junk and vegetables. food and too many sweets. Reflection Corner You know that it is important to keep your body healthy. Do you follow these good habits to keep your digestive system healthy? Circle the ones that you follow. EAD 15 SR 7 Organ Systems Circulatory System We have learned that food is down into smaller usable particles called nutrients by system. Nutrients are used by ourbroken the us body for energy to do different activities, help our body grow from diseases. But how do these nutrients reach the different parts of the body? Our body organised transport system called the circulatory system. has praotewel. anddigesive The circulatory system is an organ system that transports nutrients and other substances to of the body. diferent parts Let's Think Keywords When Iplace my hand on the left side of my chest, fluid: a substance I can feel a beating sensation. Do you feel that too? that flows easily Try it by placing your hand on the left side of your chest. The beating sensation is coming from your heart. pumps: making The heart is a part of your circulatory system. Write air or liquid move two questions you have about the circulatory system from one place to on WS 7. another Parts of the Circulatory System Blood Blood is a red fluid present in the body. It carries nutrients and othe substances to the different parts of the Blood flows through body. It also carries away the waste blood vessels. that must be removed from the body. Blood Vessels Blood flows through tubes called blood vessels to all the parts of the body. The blood vessels that transport blood away from the heart are called arteries. Artery Vein The blood vessels that carry blood to the heart are called veins. The small blood vessels that Connect the arteries and veins are called capillaries. Heart The heart is located on the left side of the chest. It is as big as our fist. It is made of muscle. The heart pumps blood. It circulates blood continuously throughout our body. 16 EAD  Organ Systems SR 8 Blood is pumped by the heart vessels and transports nutrients continuously and other to the different parts of our body. Blood flows through blood from allthe parts of our body to useful the organs that substances throughout our body. It also carries away waste later in the unit. remove waste from the body. You will learn more about this Maintaining a Healthy Heart The heart works nutrients and other continuously useful to pump blood to all the parts of the body. If the heart stopped pumping blo0d have no energy to performsubstances our bodily would not be transported to any other part of our body. We would then how to maintain a healthy heart. functions. Hence, we must take care of our heart. Read on to find out Dos Don'ts Eat fresh fruits and vegetables and drink lots of water. Avoid eating spicy, oily, and fatty food. Exercise regularly Do not watch TV or sit idle for very and play outdoors to make your heart long. and body strong. If someone in your home smokes, explain to them that smoking is bad for the heart Get enough sleep and that they must and rest. stop. Let's WorkTogether Use a chart paper and some colours to create a poster in your group on howto keep our heart healthy.Give a title to your poster. EAD 17 SR 9 Organ Systems Respiratory System We know that the food we eat is Converted into smaller particles called nutrients in the Nutrients are transported to the give us the different parts of the body through the circulatory system. energy to perform different activities. But how does our body get energy from ithesegTheseestive nutSysielart 1o get energy from nutrients, our body also needs oxygen. Where does oxygen come from? nutrients Oxygen comes from the air we breathe. Our body has an organ system that takes in air to the circulatory system. The circulatory system then transports oxygen from this air to alland the body. Oxygen along with the nutrients then provides energy to our body. During this the delpansivers dioxide produced as a waste material and is later removed from the body. The process byprwhich is ocess, carbon geis energy is known as respiration. The different organs that help us in this process together Our body respiratory system. form he Parts of the Respiratory System Nose: It is the organ through which We It hastwo nostrils and acavity calledthe take in air. nasal Pharynx: It is atube that connects cavty. the nose to the trachea. Trachea (say truh-kee-uh) or windpipe: It is a tuhe through which air passes to the lungs. Bronchi(say brawn-kai): The trachea divides into twn tubes called bronchi (singular: bronchus) that enter each lung. Lungs: They are the main respiratory organs located on both sides of our chest. They are pink in colour as they have lots of blood vessels. They are spongy because of the spaces filled with air in them. Diaphragm (say dye-a-fram): It is a large, flat muscle. It gives support to the lungs. Circle the point where the trachea divides into the bronchi. Keywords spongy: soft, like a sponge Scan me Let's Discuss Place your hand on your chest and take a deep breath. Can you feel your chest rising up and falling down? Why do you think this happens? Imagine the flow of air in your body once you breathe in, Discuss to learn about the this with your partner. respiratory system. JLEAD 18  SR 10 Organ Systems Working of the Respiratory System Respiration begins with breathing. The process of taking in air through our nose is called breathingin or inhalation. The process of giving out air through the nose is called breathing out or exhalation. One inhalation and one exhalation make up one breath. Let us look at what happens in our body when we inhale andexhale air. The following steps take place during the process of breathing. During Inhalation During Exhalation Air inhaled Air exhaled through the nose through the nose (a) The diaphragm moves downwards. (a) The diaphragm moves upwards to (b) The space in its original position. the chest cavity increases. (b) The space in the chest cavity (c) Air rushes into the decreases. lungs. (c) Air rushes out of the lungs. What happens tothe air inside the body once it is inhaled? We breathe in or inhale air through our nose. The nose has two nostrils that have hair that trap dust particles. The nostrils lead to the nasal cavity through which air passes into the pharynx. The nasal cavity has muCus that moistens the air we breathe. Air passes through the pharynx to the trachea. Air passes through the trachea, which divides into the bronchi, to reach the lungs. Air fills the lungs. The exchange of gases takes place here. Oxygen in the air enters the blood. Carbon dioxide is renmoved from the blood. Oxygen is carried by the blood to different parts of the body, where it combines with nutrients to give energy. Carbon dioxide is formed as a waste product. It is sent back to the lungs and released from the body through the exhaled air. When we breathe in air, the diaphragm moves downwards, allowingair to fill the lungs. When we Use a pencil and trace how air moves in and out breathe out, the diaphragm returns to its original of the lungs. position. LEAD 19 SR 11 Organ Systems Breathing Rate Sit still for few a you take in one minute. How many minutes and COunt the number of breathsminute you take? The number an adult human of times a person breathes in one is called their breathing rate being at rest breathes 15 to 18 times in a minute. When we are performing On breaavlhesrageti exercising and playing, do you think our breathing rate is the same relaacxitivnitg?es iks as when we are sitting or Activity Corner Let us record our breathing ratel Sit still for a few minutes. Count your breathing rate while you are sitting and record it. What do you think will happen to your breathing rate after you walk or jump? Record your prediction. Now, walk for 5 minutes and note down your breathing rate. Next, jump for 5 minutes and note down your breathing rate. Record your observations and findings on WS 11. The lungs help our body receive oxygen and remove carbon dioxide. If ourlungs do not work to taka our body will not get the oxygen needed to release energy from food. Therefore, it is very important properly, care of our lungs. We can keep our lungs healthy by playing outdoors, eating healthy food, and exerciei regularly. We must also try to keep away from areas with heavy traffic and factories as the smoke from the places can harm our lungs. Excretory System We saw how the digestive system, circulatory system, and respiratory system work from the food we eat. During these processes, waste is alsO produced together to give us eneroy in the body. Apart from digestion circulation, and respiration, there are many other processes taking place in the body which also produce waste. What happens to all this waste? The waste produced needs to be removed from the body. The process through are removed from the body is called excretion. The different organs that help inwhich these waste materials the body together form the excretory system. The waste and excess the removal of waste from the form of urine. This process is called urination. This is why the water are removed from the body in system. excretory system is also called the urinary Doyou remember that during digestion, undigested food is removed from This process of removal of undigested food from the digestive our body as solid waste or faeces? system is called egestion. Please remember that egestion is not excretion. Egestion is the removal of solid, undigested material, removal of waste produced during the different processes taking place in the body. whereas excretion is the Let's Discuss We feel the urge to pass urine several times in a day. The excess water and waste produced in our body are removed through the excretory (urinary) system. What would happen if the waste produced in our body was not removed? Discuss with your partner. 20 LEAD  SR 12 Organ Systems Partsof the Excretory System Kidneys: These are a pair of bean-shaped reddish-brown organs. They are located on either side of the backbone, just below the ribs. Ureters: These are tubes that connect the kidneys to the urinary bladder. Urinary bladder: It is a large, elastic, muscular bag-like organ that holds urine. Urethra: It is a tube-like structure connected to the urinary bladder. It has a smali opening on the other side through which urine passes out of the body. Keywords elastic: able to stretch and return to its original size Working of the Excretory System The different parts of the excretory system work together to ensure that waste does not remain in our body. Let us find out how. The kidneys are like filters. As blood passes through the kidneys, waste and excess water from the blood are removed, and it is purified. This waste and extra water form urine. The urine is then passed to the ureters. The ureters carry urine from the kidneys to the urinary bladder. The urinary bladder stores the urine until it is full. When the bladder is full, the urethra helps topass the urine out of the body. If theurinary system does not function property, the level of waste in the blood willincrease, and we wil fal sick. Hence, it is important to drink adequate amounts of water and not wait too long when we feel the urge to pass urine. LEAD 21 SR 13 Organ Systems Organ Systems Working Together Our body is healthy when all the organ systems work together. Allthe parts of the body need energy and growth. The organ systems that we learned about work together to ensure that we nutgetients to from the food we eat. Let us find out how! energy Our We take in food through our the respiratory systemoxygenbringsthatin is bodyneeded mouth. by to releaseour Oxygen energy from the nutrients. Blood Carbon dioxide Nutrients Our systemexcretory removes the waste that is UScan me produced in our body during these Urine processes. Our digestive Our circulatory system breaks system carries down the food we these nutrients eat into nutrients. and oxygen to tolearn about These nutrients different parts of organ systems are absorbed into our body. working together. the blood. Is it not amazing that all these processes take place at the same time to ensure that we get energy from the food we eat? This is how our different organ Let's Discuss systems work together, just like a team, to give us energy from the food What do you think would happen if one of we eat. Therefore, we should always the four organ systems given above failed take good care of all our organs. to perform its function in our body? Discuss with your partner and write the answer on Now, go back to SR 2. Did you put WS 14. a/against thecorrect organ systems that help you get energy? E4D 22  Organ Systems SR 14 Let's Revise A group of organsworking together to perftorm amajor function in the body is called an organ system. There are many organ systems in our body that work together to keep us healthy. Seven of these organ systems re the digestive system, respiratory system, circulatory system, excretory system, skeletal system, muscuial system, and nervous system. The four organ systems that help us in getting energy from the food we eat are as follows: Digestive System Circulatory System Respiratory System Excretory System The digestive system The circulatory system The respiratory system The excretory system helps break down the helps transport nutrients brings in oxygen to the helps in the removal of food that we eat into and other substances to body that is needed to waste produced during smaller substances the different parts of the release energy from the these processes from called nutrients, which body. nutrients and removes the body. our body can use. carbon dioxide. Reflection Corner 1. Write down the most interesting thing you learned about organ systerns in this unit. Mention why you found it interesting. The most interesting thing I learned about organ systems is Ifound it interesting because 2. Which topics do you need help with? Write them below, and discuss them with your teacher. EAD. 23