Chapter 4 Nutrition Lesson 4 Digestion and Excretion

Chapter 4 Nutrition Lesson 4 Digestion and Excretion Teacher’s notes are available in the notes section of this presentation. Next >>

Introduction A car needs gas to run. The engine of a car burns fuel, (gas), for energy. Write a paragraph: How can you relate your body's need for energy to a car's need for fuel? Where & how does your body get it's fuel?

digestion The process by which the body breaks down food into smaller pieces that can be absorbed by blood and sent to each cell in your body digestive system The group of organs that work together to break down foods into substances that your cells can use saliva A digestive juice produced by the salivary glands in your mouth

enzyme A substance that aids in the body’s chemical reactions small A coiled tube from 20 to 23 feet long, in which about intestine 90 percent of digestion takes place colon A tube five to six feet in length that plays a part in both digestion and excretion pancreas A gland that helps the small intestine by producing a blend of enzymes that break down carbohydrates and fats

excretion The process the body uses to get rid of waste excretory The group of organs that work together to remove system wastes kidneys Organs that remove waste material, including salts, from the blood

In this lesson, you will be able to explain the process of digestion. discuss how your body eliminates waste products. explain how to care for your digestive and excretory systems.

How Your Body Digests Food Digestion begins in your mouth. The word d igest comes from a Latin word meaning “to separate. ” digestion The process by which the body breaks down food into smaller pieces that can be absorbed by the blood and sent to each cell in your body It takes the body from 16 to 24 hours to digest food and remove waste products.

How Your Body Digests Food is processed in your body by the digestive system The group of organs that work together to break down foods into substances that your cells can use Turns food into substance the body can use for energy

Where Does Digestion Begin? When you crush food with your teeth, saliva mixes with the food. Amylase, an enzyme in saliva, begins breaking down carbohydrates in the food. saliva A digestive juice produced by the salivary glands in your mouth enzyme A substance that aids in the body’s chemical reactions Saliva also moistens and softens the food in your mouth, making it easier to swallow.

Pag Where Does Digestion Begin? e 12 3

Your Digestive Organs After you swallow, food moves into your esophagus, then into your stomach, then into the small intestines A coiled tube from 20 to 23 feet long, in which about 90 percent of digestion takes place

Your Digestive Organs The liver and pancreas are two important organs in the digestive system. liver A digestive gland that secretes a substance called bile, which helps to digest fats the liver also helps control the level of sugar in the blood, breaks down harmful substances such as alcohol, and stores some vitamins. pancreas A gland that helps the small intestine by producing pancreatic juice, a blend of enzymes that breaks down proteins, carbohydrates, and fats

Alcohol and the Liver If you have a drinking problem and drink long enough, the result from that kind of alcohol intake over time can be liver disease in the form of cirrhosis.

Your Digestive Organs The colon is the last stop for solid food the body Also called the large intestine can’t digest. colon A tube five to six feet in length that plays a part in both digestion and excretion Any water, vitamins, minerals, and salts left in the food mixture absorbed by the colon. Most of the water is returned to the body. The rest is waste material.

Pag e 12 4

Sequencing Take a look at Figure 4. 5 (Chewing and Swallowing) and figure 4. 6 (The Digestive System). Using these figures, summarize the steps of digestion.

In this lesson, you will be able to explain the process of digestion. discuss how your body eliminates waste products. explain how to care for your digestive and excretory systems.

Removing Wastes Excretion is a process of the excretory system. excretion The process the body uses to get rid of waste excretory system The group of organs that work together to remove wastes The excretory system also controls the body’s water levels.

The Main Organs of the Excretory System Kidney’s Bladder Colon … Large Intestine Your skin Lungs remove waste from your body

Removing Wastes The kidneys help in the production of red blood cells and the regulation of blood pressure. kidneys Organs that remove waste material, including salts, from the blood Liquid wastes are removed through the body in the form of urine All the blood is filtered through the kidneys about 20 times a day The bladder stores urine until it is ready to be The body needs about passed out of the body. 6 -8 glasses of water a day to help the kidneys do their job

Textb ook p a ge 12 5

Removing Wastes Your body’s solid wastes are called feces, which are stored in the colon until that organ becomes full. Strong muscles in the wall of the colon begin to contract, which is a signal that the colon must be emptied.

Caring for Your Digestive and Excretory Systems Eat a balanced diet with low-fat, high-fiber foods Fiber helps your digestive and excretory system work properly Eat meals on a consistent schedule to help food move through your body at a steady pace. Drink plenty of water. Some 60 to 70 percent of your body is water. Water helps the digestive and excretory system work properly. Brush your teeth at least twice a day, floss, and get dental checkups twice a year. our teeth play an important role in the early stages of the digestive process. Get regular physical activity.

Lesson 4 Review What I Learned Vocabulary Define digestion. Digestion is the process by which the body breaks down food into smaller pieces that can be absorbed by the blood.

Lesson 4 Review What I Learned List Identify the major parts of the digestive system. mouth, esophagus, stomach, small intestine, liver, gall bladder, pancreas, and colon

Lesson 4 Review What I Learned Explain What is the function of the kidneys? Kidneys remove waste material, including salt, from the blood.

Lesson 4 Review What I Learned Describe How can you take responsibility for caring for your digestive and excretory systems? Eat regular, balanced, low-fat, high-fiber meals; drink plenty of fluids; care for your teeth; and exercise regularly.

Lesson 4 Review Thinking Critically Apply Your friend Sherry doesn’t like the taste of plain water. However, you know that drinking enough water is important for the digestive and excretory systems. What might you say to Sherry to influence her to make a healthy choice to consume more water? Sample answer: Encourage Sherry to drink flavored water, fruit juices, or eat fruits, vegetables, and soups.

Lesson 4 Review Thinking Critically Hypothesize How do the digestive and excretory systems work together and influence each other? Sample answer: Systems work together to keep the body functioning. When one system is not working properly, it can negatively affect the other systems.

End of Chapter 4 Nutrition Lesson 4 Digestion and Excretion