2. ©2005 Texas Trade and Industrial Education1 Cosmetology Digestive & Excretory Systems

3. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 2 Performance Objectives Upon completion of this lesson, the student will be able to identify and describe the key functions and processes of the digestive and excretory systems. The student will demonstrate these competencies by completing a written test with a minimum of 80 percent accuracy.

4. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 3 Specific Objectives Identify the key responsibility of the digestive system Describe the digestive process List and describe the five basic activities the digestive system performs to prepare food for use by cells Identify the parts of the digestive tract and their main functions Identify the key responsibility of the excretory system Name the key organs that play a role in the excretory system and their functions

5. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 4 Key Responsibility of the Digestive System Responsible for changing food into nutrients and waste Allows the body’s cells to convert food into high-energy molecules that run the cell’s machinery

6. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 5 The Digestive Process Digestive enzymes are chemicals that change certain kinds of food into a form that can be used by the body Once the food is in a soluble form, it is transported by the bloodstream and used by the body’s cells and tissues The entire digestive process takes about nine hours to complete

7. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 6 The 5 Basic Activities the Digestive System Performs Ingestion - taking food into the body Peristalsis - the physical movement or pushing of food along the digestive track Digestion - the breakdown of food Absorption - the passage of digested food from the digestive tract into the cardiovascular and lymphatic systems for distribution to the body’s cells Defecation - the elimination from the body of those substances that are indigestible and cannot be absorbed

8. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 7 Digestive Tract: Parts and Functions Mouth, or oral cavity: Teeth bite off and chew food into a soft pulp that is easy to swallow Chewing mixes the food with watery saliva to make it moist and slippery Pharynx : Begins the process of swallowing, moving the food from the mouth

9. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 8 Digestive Tract: Parts and Functions (2) Esophagus: A collapsible, muscular tube that secretes mucus and transports food from the throat to the stomach Stomach: Begins the digestion of proteins (carbohydrates begin to digest in the mouth), mashes the food into soupy consistency and passes the contents to the small intestine The stomach also produces digestive juices that attack the food and dissolve its nutrients

10. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 9 Digestive Tract: Parts and Functions (3) Small intestine: Approximately 21 feet in length and 1 inch in diameter, the small intestine performs the major portion of the absorption and digestion Enzymes continue the chemical attack on the food, and finally the nutrients are small enough to pass through the lining of the small intestine and into the blood The nutrients are carried away to the liver and other body parts to be processed, stored, and distributed

11. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 10 Digestive Tract: Parts and Functions (4) Large intestine: Approximately 5 feet in length and 2.5 inches in diameter Absorbs spare water and minerals through the walls of the large intestine, back into the blood Forms feces and removes it from the body

12. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 11 Key Responsibility of the Excretory System A group of organs responsible for purifying the body by eliminating waste matter The metabolism of body cells forms various toxic substances that, if retained, could poison the body

13. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 12 Key Organs of the Excretory System Kidneys : The most important organ in the excretory system Kidneys clean the body’s blood 40 times a day The waste from the blood creates urine

14. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 13 Key Organs of the Excretory System (2) Liver : Largest internal organ in the body Functions as part of the digestive, excretory, and circulatory systems Produces bile and discharges it to gall bladder, and then passes to the small intestine where it breaks down molecules

15. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 14 Key Organs of the Excretory System (3) Skin : Eliminates waste through perspiration Large intestine: Eliminates decomposed and undigested food as described in the digestive system section Lungs: Exhale carbon dioxide

16. ©2005 Texas Trade and Industrial Education Cosmetology I: Digestive & Excretory Systems 15 Summary The digestive and excretory systems perform important functions for the body. They also work with the other systems to maintain homeostasis (maintaining the body’s internal environment).