GRADE8-DIGESTIVE-PPT.pptx......yess Soo it's the idl

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1. The Digestive System Prepared by: Cherrie Dee D. Ferrater 8 th grade

2. Objectives: Identify the different organs that comprise the human digestive system and its functions. Illustrate the different enzymes that are involved in the digestion process. Expound precautionary measure to maintain and keep healthy body.

3. Activity 1: Tummy Puzzle M W Q S D F F O O D M E T S Y O T R S A L I V A Z G S Q M K U B P A N C R E A S A O G A H T E E T H X M P X S L P D L H H H J O C K L P F H L H W L Q S D F N A H A H S Q B A T I G G H J G M K L A F Q L G W N T A S W U O R T R Q D A U T T G F G H E T M J Y R K D S L E P F S W E S G H N E J D K L S V L I V E R F B X C D E Q E T Y G H J K V D F G T A R X A I W G H J K D S A N U S Q E R N T H J K S A E W A M X C B F E Q L A R G E I N T E S T I N E F

4. The Human Digestive Tract The human digestive tract is around three meters long. It has four main functions: 1. Ingestion is to take in food through the mouth . 2. Absorption is the process of absorbing food in the form of nutrients into the blood stream of the body. 3. Assimilation is the process of nutrients being absorbed by each cell of the body in the form of energy. 4. Excretion is the elimination of materials that cannot be digested.

5. The Human Digestive Tract The digestive system is composed of different organs. Each digestive organ can be classified as either an accessory organ or a part of the alimentary canal. Accessory organs assist in the digestion of food. Salivary glands Liver Gall bladder Pancreas

6. The Human Digestive Tract 2. The alimentary canal - contains organs where food passes through. The mouth Pharynx Esophagus Stomach Small intestine L arge intestine Rectum.

7. The Oral Cavity Ingestion is the process in which food is taken into the body through the mouth for digestion, absorption, and elimination. This process is accomplished by the mouth or the oral cavity . The mouth is the first portion of the digestive tract (or alimentary canal). It receives food and digests the food by chemical and mechanical means. Physical digestion involves the teeth. Mastication, or chewing, is performed by the teeth. Food is cut into smaller pieces so that it can digest easily.

8. The Oral Cavity Humans have four types of teeth . I ncisors , which are used for cutting T he cuspids (canines ) which are used for tearing The bicuspids (premolars ) which are used for crushing, mashing, and grinding, and T he molars- which have broader crowns that are used for crushing and grinding.

9. FOUR TYPES OF TEETH

10. Initial chemical digestion depends on an accessory organ- the salivary gland. Chemical digestion involves enzymatic action, which is accomplished through the saliva . The saliva contains salivary amylase that helps digest carbohydrates . Saliva is secreted by the three pairs of salivary glands found in the oral cavity:

11. 1. Parotid gland- lies in front of the ear; contains saliva near the second upper molar 2. Sublingual gland- lies under the floor of the mouth ; contains saliva by numerous sublingual ducts 3. Submandibular gland- lies deep in the mouth ; contains saliva on either side of the lingual frenulum (small fold of the tongue)

12. The Pharynx and the Esophagus The bolus (mass of food) is the end product of the food that has been chewed, partially digested, and lubricated by the saliva. It is now ready to be swallowed . The tongue pushes the bolus into the pharynx, which is the passageway for air, food, and water. Food is then delivered to the esophagus. A flap called epiglottis closes the air opening when food is swallowed. It prevents the bolus from entering the trachea and ensures that the food enters the esophagus . The bolus in the esophagus keeps moving down by a rythmic , involuntary action called peristalsis.

13. The Pharynx and the Esophagus

14. The Stomach The bolus passes through the stomach after leaving the esophagus. The stomach is a highly muscularized J-shaped sac that stores food and continues the digestion that began in the mouth. It can stretch up to nearly twice its original size and can hold up to two liters of food. The environment inside the stomach is highly acidic . The lining of the stomach secretes gastric juice that contains hydrochloric acid (HCL ).

15. The Stomach Pepsin is the enzyme responsible for digesting proteins . The environment inside the stomach is acidic and can digest proteins. Fortunately, the walls of the stomach are protected by mucus to prevent the stomach from digesting itself. Goblet cells are responsible for producing the mucus that lines the walls of the stomach.

16. The Stomach

17. The Small Intestine The small intestine is named such because of its diameter; yet, even though its diameter is small, it is the longest part of the digestive tract. Its is approximately seven meters long . It is divided into three regions : the duodenum the jejunum the ileum. It is in the small intestine where digestion is completed. The completion of chemical digestion depends on three accessory organs- pancreas, liver and gall bladder.

18. The Small Intestine

19. The Pancreas produces enzymes that will digest carbohydrates , protiens , and fats . The pancreas should also release alkaline fluids to neutralize chyme , which is acidic.

20. The liver is another accessory organ. It produces bile that helps digest fats. Excess bile produced by the liver is stored in the gall bladder. Bile facilitates the breakdown of fat globules into smaller droplets for further digestion by lipases .

21. The Large Intestine The undigested materials are transported to the large intestine (or colon) after the absorption of nutrients is completed. Another function of the large intestine is to absorb water from the remaining undigested materials.

22. The large intestine is divided into several segments: ascending colon transverse colon descending colon sigmoid colon- leads to the final portion of the large intestine called rectum . The rectum is where the feces are formed . It passes through the anal canal when the feces are expelled outside the body.

23. COMMON DIGESTIVE SYSTEM DISORDERS 1. Dental caries - is also known as tooth decay or a cavity. It is characterized by demineralization and destruction of the different layers of the tooth 2. Heartburn - is characterized by burning sensation in the chest. It is caused by the reflux of acid from the stomach back to the esophagus.

24. COMMON DIGESTIVE SYSTEM DISORDERS 3. Gastric ulcer - is also known as stomach ulcer. A type of bacterium, Helicobacter pylori, is one of the most common causes of ulcer 4 . Appendicitis – is the inflammation of the appendix. Appendicitis, based on experiments, is the result of obstruction of the inside space of the appendix. 5 . Diarrhea - is characterized by having three or more loose liquid bowel movements per day.