1. Accessory Structures Important additional structures of digestive system. Although food pass through them they play a vital role in proper digestion and absorption

2. SALIVARY GLANDS Produce a fluid called saliva which softens and binds food into a Enzyme salivary begins chemical digestion of carbohydrates (hydrolysis) [carnivores which gulp their food lack enzymes in saliva ]

3. SALIVARY GLANDS 3 pair of exocrine glands located around the oral cavity [, & submaxillary]

4. Accessory Organs- Pancreas Produces pancreatic fluid which is sent to the Includes many enzymes: trypsin and chymotrypsin (proteins), pancreatic amylase (starch) and lipase (fats). Also contains a bicarbonate which

5. Pancreas Functions as both an and an gland -Endocrine since it into the blood steam which moves sugar in blood into the cells of the body - Exocrine since it which contain about 28 known digestive enzymes

6. PANCREATIC JUICES This fluid is thus the strong acid mixture (chyme) which arrives in the duodenum from the stomach Flows through a short tube [pancreatic duct] into the duodenum

7. Accessory Organs- Liver Largest internal organ of humans Secretes which is stored in the Bile salts are crucial in the digestion of fats

8. Liver One of the most vital organs to the body because of its many functions Stores and releases carbohydrates, packages fats, synthesizes enzymes and clotting factors, regulates blood cholesterol, stores fat soluble vitamins (A,D,E,B12), breaks down a variety of foreign substances

9. Accessory Organs-Gall Bladder Stores extra bile between meals When food enters the small intestine the gall bladder sends bile into the duodenum

10. Gall Bladder After meals in response to food in the and duodenum, gall bladder contracts through common bile duct into duodenum

11. Digestive Tract

12. SecretionSite of productionFunction salivamouthcontributes to starch digestion via salivary amylase; lubricates the inside of the mouth to assist in swallowing mucusmouth, stomach, small intestine, and large intestine protects the cells lining the innermost portion of the digestive tract; lubricates food as it travels through the digestive tract enzymesmouth, stomach, small intestine, and pancreas promote digestion of food masses into particles small enough for absorption into the bloodstream acidstomachpromotes digestion of protein bileliver (stored in gall bladder)suspends fat in water, using bile salts, cholesterol, and lecithin to aid digestion of fats in small intestine bicarbonatepancreas and small intestineneutralizes stomach acid when it reaches the small intestine hormonesstomach, small intestine, and pancreas stimulate production and/or release of acid, enzymes, bile, and bicarbonate; help to regulate peristalsis

13. Ulcers Can occur in the (gastric) or the beginning of the small intestine ( ). It was thought that they may be caused by and HCl or more recently by bacterial infection.

14. Inflammatory Bowel Diseases Crohn’s Disease - inflammation of the intestinal tract (Burril Crohn) resulting in abdominal cramping, and fever. Ileitis/colitis - may require surgery and drug therapy IBDs( ) may be caused by virus or which can be treated surgically and/or treated with anti- inflammatory drugs.

15. Hepatitis a. Hepatitis A () caused by spread through  water and food b. Hepatitis B (serum hepatitis) acquired from transfusions or exchange of body fluids (tears, saliva, blood, semen) [vaccine available] c. Hepatitis C Infected blood –

16. Cirrhosis Chronic disease of the with degeneration of liver cells Caused by, hepatitis C and nutritional deficiencies as well as poisons and infections

17. Gallstones Cholesterol in the, blocking the bile duct and preventing the flow of bile to the small intestine

18. Anorexia Nervosa & Bulimia Eating disorders caused by an inaccurate body image Obesity: Hormonal, and lifestyle factors

19. Chapter 6 Review Why are some amino acids classified as essential? Describe the relationship between the organs in the digestive tract. What are the benefits of having stomach stapling? What are the risks? Summarize chemical digestion of macromolecules. Explain how glucose levels are affected after meals. Include the effects of different foods. The human body takes in matter from the environment in the form of food and water. The human digestive system processes the food and water in order to obtain the macromolecules it needs for survival.

21. Chapter 6 Summary Food passes through the digestive tract—the mouth, pharynx, esophagus, stomach, small intestine, and large intestine—during physical digestion. The accessory organs—the salivary glands, liver, gall bladder, and pancreas—supply chemicals that also contribute to the digestion of food as it passes through the digestive tract. The stomach supplies chemicals to aid digestion as well as generating physical contractions to physically break down food. The food is eventually liquefied into soluble units that can pass through cell membranes for transport via the circulatory system to all the cells in the body. The waste materials from the digestive process leave the body via the large intestine.

22. Chapter 6 Summary The nutrients that food supplies include carbohydrates, lipids (fats), protein, and nucleic acids. Carbohydrates and lipids are broken down to supply energy; lipids also supply material for the cell membranes. Proteins are more structurally and functionally diverse than carbohydrates and lipids. They assist in transport, immunity, and muscle action and are used to make up most cellular structures. Nucleic acids direct growth and development. Enzymes speed up chemical reactions, particularly for the production of energy. Vitamins and minerals are organic and inorganic substances that enable chemical reactions to occur and aid in tissue development and growth and immunity. These substances are needed for a healthy, functional human body.

23. Chapter 6 Summary Disorders of the digestive system and its accessory organs include ulcers, inflammatory bowel disease, hepatitis, cirrhosis, and gallstones. All disorders that affect digestion, including eating disorders, can seriously damage overall health by depriving the body cells of the nutrients they need to survive.