1. Digestive System

3. Human Digestive System

4. Functions of the Digestive System Teeth: begin digestion by chewing (Mastication) Salivary glands: secrete enzymes that begin digestion. Thyroid: regulates metabolism, hypothyroidism and hyperthyroidism. Esophagus: brings food into stomach by means of peristalsis, muscular action of the esophagus. Reverse is anti-peristalis.

5. Esophagus

6. Stomach connection to the esophagus E cardiac notch CN fundus F body B angular notch AN pyloric antrum Py area of pyloric sphincter PS 1st part of the duodenum D lesser curvature LC greater curvature G

7. Function of the Stomach Organ of digestion. Saclike shape that is located between the esophagus and the intestines. Stomach is a muscular, elastic, pear shaped bag, lying crosswise in the abdomen beneath the diaphragm. Changes size according to its position and amount of food inside. Approximately 12 inches and can hold about 1 quart in an adult.

8. Flow through stomach Food enters through esophagus. Valve regulates flow, if bad valve, results in heartburn As food enters, gastric juices are used to break down the food. Some substances are absorbed through muscle lining of stomach (Alcohol). Food empties from the end of the stomach into the duodenum.

9. Small Intestine

10. About 20 feet long Coiled in center of abdomen. Divided into 3 sections: duodenum, jejunum, and ilium. Secretes a hormone called secretin, which stimulates the pancreas to produce digestive enzymes. Area where majority of digestion of food and absorption occurs.

11. Duodenum

12. Pancreas

14. Functions of Pancreas Organ that secretes digestive enzymes and hormones. Yellowish organ about 7 inches long. Lies beneath the stomach and is connected to the small intestine at the duodenum. Contains enzyme producing cells that secrete 2 hormones, insulin and glucagon. They are secreted directly into blood, together they regulate the level of glucose in blood.

15. Insulin and Glucagon Insulin lowers the blood sugar level and increases the amount of glycogen in the liver. Glucagon slowly increases the blood sugar level if it falls too low. If the insulin secreting cells do not work properly, diabetes occurs. Produces enzymes to digest foods and break down starches. Neutralizes chyme, which is a thick semifluid mass of partly digested food.

16. Large Intestine

17. Function of Large Intestine Responsible for absorption of water and excretion of solid waste. Food and waste are moved along by rhythmic contractions (Peristalsis)

18. Liver

19. Healthy Liver vs. Hepatitis

20. The Liver Largest glandular organ of the body. Weighs approx. 3 pounds. Is reddish brown in color and is divided into four lobes of unequal size and shape. Lies on the right side of abdomen beneath the diaphragm. Blood is carried to liver by hepatic artery and the portal vein. Hepatic: carries O2 rich blood from aorta. Portal: carries blood containing digested food from the small intestine.

21. The Liver Produce substances that break down fats. Converts glucose to glycogen Produces urea (main substance of urine) Makes certain AA Filter substances from the blood (Alcohol) Storage of vitamins and minerals Maintain proper level of glucose in blood.

22. Gall Bladder

23. Function of the Gall Bladder Organ that stores and concentrates bile. Connected to the liver, which produces and secretes bile, by the hepatic duct. Bile emulsifies fats and neutralizes acids in partly digested food. Bile duct opens, and bile flows from gallbladder and into duodenum. Gallstones: substances contained in bile crystallize.

24. Spleen

25. Function of the Spleen Organ that creates lymphocytes for the destruction and recycling of old RBC. Also serves as a blood resevoir, it supplies the body with blood in emergencies such as a bad cut. Tucked under the left side of the diaphragm, and is protected by rib cage.

26. Kidneys

27. 2 Small organs located near vertebral column in small of back. Left is slightly higher than right kidney. One function is to filter: to separate urea, mineral salts, toxins, and other waste products form the blood. They also conserve water, salts, and electrolytes.