DIGESTIVE SYSTEM 120739 pm_0174e3 125241 pm_4b53bf.pptx

Digestive system

1. DIGESTIVE SYSTEM DEFINITION Digestive system is made up of gastrointestinal tract (GI tract) or alimentary canal and accessory organs, which help in the process of digestion and absorption .

2. 1. Ingestion or consumption of food substances . 2. Breaking them into small particles . 3. Transport of small particles to different areas of the digestive tract . 4. Secretion of necessary enzymes and other substances for digestion . 5. Digestion of the food particles . 6. Absorption of the digestive products (nutrients) . 7. Removal of unwanted substances from the body. Functions of the digestive system

3. Primary digestive organs are: Mouth​ Pharynx​ Esophagus Stomach Small intestine and Large intestine. Accessory digestive organs are: Teeth Tongue Salivary glands Exocrine part of pancreas Liver and Gallbladder. COMPONENTS OF DIGESTIVE SYSTEM

4. Proccess of digestion During digestion two main processes occur at the same time.​​​ •Mechanical digestion: larger pieces of food get broken down into smaller pieces while being prepared for chemical digestion. Mechanical digestion starts in the mouth and continues in to the stomach. •Chemical digestion: several different enzymes break down macromolecules into smaller molecules that can be more efficiently absorbed. Chemical digestion starts with saliva and continues into the intestines. ​​​​​​​

5. ORAL CAVITY(mouth) The oral cavity, or more commonly known as the mouth or buccal cavity, serves as the first portion of the digestive system . SALIVARY GLANDS Salivary glands release their secretions into ducts that lead to the mouth. TEETH The teeth, which are the chief structures of the oral cavity, tear and grind ingested food into pieces small enough for digestion . TONGUE The tongue enables the digestion of food through compressing and pressing food against the palates;

6. Pharynx,Epiglottis and Oesophagus Pharynx: The pharynx, which is the passageway for food and air, is about five inches (5") long. Epiglottis :A small flap of skin called the epiglottis closes over the pharynx to prevent food from entering the trachea and thus choking. Esophagus: The esophagus (also spelled oesophagus/esophagus) or gullet is the muscular tube in vertebrates through which ingested food passes from the mouth area to the stomach.

7. Stomach and small intestine Stomach: The stomach lies between the esophagus and the first part of the small intestine (the duodenum). It is on the left side of the abdominal cavity; the fundus of the stomach lying against the diaphragm. Small intestine: The small intestine is the site where most of the chemical and mechanical digestion is carried out. The three main sections of the small intestine is The Duodenum, The Jejunum, The Ileum.​​​​​

8. Large Intestines and Rectum Large Intestin e: The large intestine (colon) extends from the end of the ileum to the anus.The large intestine is divided into the cecum, colon, rectum, and anal canal. Rectum: This is a slightly dilated section of the large intestine about 13 cm long. It leads from the sigmoidcolon and terminates in the anal canal. Anal canal: This is a short passage about 3.8 cm long in the adult and leads from the rectum to the exterior. Two sphincter muscles control the anus; the internal sphincter, consisting of smooth muscle,

9. Pancreas, Liver, and Gallbladder ​​​​​​​​ The pancreas, liver, and gallbladder are essential for digestion. The pancreas produces enzymes that help digest proteins, fats, and carbohydrates, the liver produces bile that helps the body absorb fat, and the gallbladder stores the bile until it is needed.

10. Metabolism Metabolism is the sum of all biochemical reactions in the body; however, it primarily focuses on the reactions needed to convert food into energy; it is the sum of reactions needed to support the life of an organism. Catabolism : Catabolic processes break down large molecules into smaller ones releasing chemical energy, which is stored as adenosine triphosphate (ATP), and heat. Anabolism : This is building up, or synthesis, of large molecules from smaller ones and requires a source of energy, usually ATP.

11. DISORDERS OF THE DIGESTIVE SYSTEM Disease of the mouth : This includes: Gingivitis Dental Carries and Tumours of the mouth ( Squamous cell carcinoma ) Diseases of salivary glands : This includes: Mumps Tumours of the salivary glands (S alivary adenoma & Carcinoma ) Disease of the pharynx Pharyngytis Disease of the Oesophagus Gastro-oesophageal reflux disease (GORD) Achalasia Congenital abnormalities

12. DISORDERS OF THE DIGESTIVE SYSTEM CONT. Diseases of the stomach Gastritis Peptuc ulcers Gastroentritis Stomach cancer Diseases of the intestines Celiac disease Inflammatory bowel disease Small intestinal bacterial overgrowth Irritable bowel syndrome

13. DISORDERS OF THE DIGESTIVE SYSTEM CONT. Diseases of the pancreas Pancreatitis: Acute & Chronic Disease of the liver Hepatitis liver cirrhosis Fatty liver disease Liver failure Diseases of the gallbladder Cholecystitis Cholegitis Jaundice

14. Questions 1.The part of the pharynx that performs dual passage way is (a) Oesophagus. (b) Nasopharynx (c) Oropharynx. (d) Laryngopharynx. 2. Which ofthe following accessory organs is NOT associated outside the alimentary canal? a)Pancreas b)Salivary glands c)Gastric glands d)Liver

15. Questions 3. The accessory organs of digestion include de following EXCEPT? (a) Pancreas (6) 3 pairs of salivary gland (c) Billiary tract and liver (d) Rectum and anal canal. 4. The length of the small intestine is about (a) 10m (b) 5m (c) 6m (d) 8m

16. Questions 5.Most digestive enzymes are produced in the (a) Mouth and oesophagus (b) Oesophagus and stomach (e) Small intestine and pancreas (d) Liver and gall bladder. 6. Where does mechanical digestion start from? (a) stomach (b) oesophagus (c) mouth (d) pancreas

17. Questions 7. What part of the digestive system is known as the Buccal cavity? (a) pharynx (b) epiglottis (c) Mouth (d) Stomach 8. Bile is stored in the ? (a) pancreas (b) liver (c) gallbladder (d) ileum

18. Questions 9. ………. Is the inflammation of the gums? (a) Stomatitis (b) Oral candidiasis (c) Gingivitis (d) Mumps 10. ……. Is the inflammation of the stomach lining? (a) Gastroenteritis (b) Stomatitis (c) Gastritis (d) Gastroparesis