Lesson 12: The Urinary System PDF

## Lesson 12: The Urinary System **Important Question:** What are the parts of the urinary system? **Let's Try!** With your group arrange the jigsaw puzzle that your teacher will provide. What picture was formed? Try to tell something about the picture. ### Parts of the Urinary System * Kidneys...

## Lesson 12: The Urinary System **Important Question:** What are the parts of the urinary system? **Let's Try!** With your group arrange the jigsaw puzzle that your teacher will provide. What picture was formed? Try to tell something about the picture. ### Parts of the Urinary System * Kidneys * Ureters * Urinary Bladder * Urethra Everyday, the body takes in food and liquids. However, not all of these are absorbed by the body. The materials not utilized by the body are eliminated. When wastes are not removed from the body, they can eventually poison the body. That is why your body has the systems that aid in the excretion of these wastes. ### Excretion Excretion is the process by which waste materials are removed from the body. You have learned in the previous lessons that carbon dioxide is excreted by the lungs while undigested food or feces are excreted through the large intestine and reticulum. Excess water and salt are also eliminated through pores in the skin. You will now learn about the system responsible for excreting most of the liquid wastes from the body, the **urinary system**. The main parts of the urinary system are the kidneys, ureters, urinary bladder, and urethra. The liquid waste of the body filtered through this system is called urine. ### Kidneys The kidneys are two bean-shaped organs on each side of the body. They are the main organs of the urinary system. The kidneys filter and clean the blood to remove waste substance and ensure that only useful substances stay in the blood that circulates throughout the body. The kidneys remove excess water, salts, urea, and other wastes from the blood. Each kidney has thousands of filters called nephrons that filter the blood about 300 times a day. The blood is carried to the kidneys, which filters excess water and waste from it. Then, the blood goes back to the heart and then to the lungs to receive oxygen. The blood then returns to the heart to be pumped and distributed to the different parts of the body. You will learn more about this in the next lessons. ### Ureters The urine flows out from the kidneys to the urinary bladder through the two ureters. The smooth muscles of the ureters move by peristalsis to move the urine towards the urinary bladder. ### Urinary Bladder The urinary bladder is a hollow muscular organ where urine is temporarily stored. The muscles of the bladder contracts to push the urine out of the body. ### Urethra Urine is emptied from the bladder and leaves the body through the urethra. The urethra is a tube at the bottom of the bladder. The length of the urethra varies in males and females. The urethra has a sphincter muscle which serves as a valvelike structure to help regulate the outflow of urine. Urination is the process of eliminating urine. Holding back urination can be harmful. One should urinate as the need arises. The amount of urine that passes through the body varies according to the amount of fluid a person drinks and the amount lost in the form of perspiration. On the average, however, the urine output may be about 1.4 liters each day. The nature of urine varies too. Its color and odor may vary according to the intake amount of water or drinks. The turbidity of urine depends on the amount of salts in the diet. ### How to Take Care of the Urinary System Urinary system is very important to excrete most of the liquid wastes from the body. Therefore, it should be taken care of properly. Here are some ways to take care of the urinary system: * Drink eight to ten glasses of water every day. Liquids help the body get rid of its wastes through perspiration and urination. * Have a balanced diet every meal. Avoid eating junk foods and salty foods as excessive salt intake may overwork the kidneys. * Eat plenty of fruits and vegetables. All fruits and vegetables contain lots of fiber. Fiber is important in your diet because it helps clean the stomach through regular bowel movement. * Take a bath every day to eliminate the dead cells that block the pores of the skin. * Exercise regularly. It helps the body get rid of its wastes through sweating and exhaling carbon dioxide. * Avoid holding back urination. * Get enough sleep and rest. Most urinary ailments worsen because of lack of sleep and rest. ### Let's Explore: How Filtration Works **Science Skills**: Observing, Measuring, Communicating **Time Frame**: 20-30 minutes **You Will Need**: * Two big jars (like mayonnaise or jam jars) * Filter paper * Rubber band * Water * Garden soil **What to Do**: 1. Get two big jars. 2. Cover one of the jars with filter paper and secure it with a rubber band. Make sure the filter paper completely covers the jar opening. 3. Get the other jar and fill it halfway with water. Add approximately a spoonful of garden soil and stir it until it becomes muddy. 4. Slowly pour the muddy water into the jar with filter paper. 5. Observe the water that passes through the filter paper. **Questions**: 1. What does the filter paper represent in the urinary system? 2. What does the muddy water represent? 3. What does the filtered water represent? ### Let's Go Beyond: What is urinalysis and how does it help in assessing the urinary function and diagnosing possible urinary diseases? ### Let's Recall Draw the urinary system on your notebook. Label the parts and give its function. ### Let's Check! **Choose the letter of the best answer.** 1. What organ of the urinary system acts as a temporary storage of urine? * a. kidney * b. ureter * c. urethra * d. urinary bladder 2. By what process does the body eliminate waste products from the body? * a. circulation * b. digestion * c. excretion * d. ingestion 3. What will happen to the body when the kidneys stop working? * a. The body accumulates poisonous substances in the blood. * b. The body becomes healthy and strong. * c. The body sweats a lot. * d. The body will be dehydrated. 4. What is NOT filtered from the blood by the kidneys? * a. excess salt * b. excess water * c. oxygen * d. urea 5. Urine is finally forced out of the body by the * a. contraction of the smooth muscles of the bladder * b. peristalsis of the smooth muscles of the ureters * c. the pumping of the cardiac muscles of the heart * d. the filtering of the nephrons of the kidney **Answer the following questions.** 1. What are some of the good habits that control and prevent diseases of the urinary system? 2. Why should we drink plenty of water every day? 3. Why should we take care of our urinary system? ### Let's Apply It! Read information about kidney transplant using internet and/or library sources. You may also interview medical personnel like nurses and doctors. Why is urinalysis needed? How is it done?