St. Lawrence School Subject - Science Class - 4
Chapte - Human Body : Digestive and Excretory System
( part - 2 )
Define the terms....
* Digestion - The process by which food is broken down into a simpler form so that it
can be easily taken in or absorbed by our body is called digestion.
* Excretion - The process by which wastes get removed from our body is called
excretion.
* Oesophagus - The food pipe ( oesophagus ) passes the food from the mouth to the
* Ureters - Urine is transported from the kidneys to the urinary bladder through thin
tubes called ureters.
* Saliva - It is a liquid that mixes with the food in a mouth.
* Faeces - The large intestine absorbs water from this undigested food and forms
waste products called faeces. Short answer questions...... 1) How does the digestive system help us? 2) Name the parts Of the digestive system. 3) What is excretion? 4) Name the parts of the excretory system. 5) list three habits that should be followed for healthy digestive and excretion system in the body. Long answer questions...... 1) Describe the various parts of the digestive system. 2) Describe the various parts of the excretory system. 3) Discuss the importance of chewing food well for digestion and excretion in the body. Short answers...... Ans1. The digestive system helps to break down the food into a simpler form and released nutrients that can be used by our body. Ans2. The main parts of digestive system are mouth, food pipe, stomach, small and large intestines, liver, rectum and anus. Ans3. The process by which wastes get removed from our body is called excretion. Ans4. The excretory system made up of - 1) A pair of kidneys. 2) A pair of ureters. 3) Urinary bladder 4) Urethra
Ans5. Three habits we should follow for healthy digestive excretory system are- a) Wash your hands properly before and after eating food. b) Chew food properly. c) Eat balance diet avoid junk food. Long answers...... Ans1. The various parts of digestive system are - a) Mouth- The teeth inside the mouth helps to break and chew food then it is mixed with saliva which makes it easy to swallow. b) Food pipe - It passes the chewd food from the mouth to the stomach. c) Stomach - Here is food further by chewing broken down into smaller pieces with the help of digestive juicrs. d) Small intestine - It is a long and hollow tube like structure. Digestion is completed here and the useful nutrients from the food are absorbed into blood. e) Liver - It is produced useful digestive juices. f) Large intestine - It is absorbed water from this undigested food and forms waste products called faeces. g) Rectum - Faeces are stored in the rectum for a short time before being passed out through anus. h) Anus - Faeces are removed from the body through the anus.
Ans2. The various parts of excretory system are - a) Kidneys - Urine is formed inside the kidneys. Urine contains harmful substances that are formed inside our body. b) Ureters - Urine is transported from the kidneys to the urinary bladder through thin tubes called ureters. c) Urinary bladder - Urine is stored inside the urinary bladder. d) Urethra - Urine is released out of our body through the urethra. Ans3. It is important to chew your food properly because chewing breaks down the food into smaller particles otherwise large food particles reach your stomach, which take longer in digestion by our our body. So digestion may not occur properly and nutrients from the food may not be released completely for absorption into the body. Chewing and a healthy digestive system helps in formation of proper faeces. This leads to regular bowel movement. It is important for our body should get Of the toxins and waste materials in our boby, which prevents digestive disorders and helps us stay healthy. * Draw a diagram of excretory system. * Draw a diagram of digestive system.
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