1. Chapter 24 The Digestive and Urinary Systems

2. Section 1 The Digestive System Objectives: Compare mechanical digestion with chemical digestion. Describe the parts and functions of the digestive system.

3. Major Functions of the Digestive System Break down ingested food Put nutrients into the bloodstream Remove waste from the body

4. Organs of the Digestive System Mouth- teeth, salivary glands, tongue Esophagus Stomach Small Intestine Large Intestine Pancreas Liver Gall bladder Accessory Organs

5. Mouth Digestion begins here! Teeth and tongue are used in mechanical digestion- physical breakdown of food Saliva and enzymes begin chemical digestion- chemical breakdown of food

6. Esophagus Muscular tube that connects mouth to stomach Moves food downward by peristalsis, or muscular contractions Epiglottis seals off windpipe during swallowing to prevent choking

7. Stomach- Mechanical and Chemical Digestion Muscular pouch that expands to hold your food Hydrochloric acid (HCl) and the enzyme pepsin combine to form gastric juice A gummy coating of mucus protects the stomach lining from the strong chemicals Chyme, a thick liquid containing partially digested food, is produced here

8. Pancreas Makes digestive enzymes Makes hormones that regulate sugar levels

9. Small Intestine Most chemical digestion occurs here! Inner surface is covered in villi and microvilli, millions of tiny finger-like projections that absorb nutrient molecules from the chyme The villi create a large surface area so as many nutrients as possible can be absorbed Longest portion of the digestive tract

10. Liver Makes bile to break up fat Stores nutrients Breaks down toxins

11. Gallbladder Temporarily stores bile and releases it into the small intestines

12. Large Intestine No digestion occurs here Water is absorbed from remaining food Waste material, feces, is prepared for elimination from the body

13. Rectum Stores feces until they can be expelled through the anus.

14. Section 2 The Urinary System Objectives: Describe the parts and functions of the urinary system. Explain how the kidneys filter blood. Describe three disorders of the urinary system.

15. The Urinary System Excretion is the process of removing waste products from the body. The urinary system removes waste products like carbon dioxide from the body.

16. The Kidneys as Filters The kidneys are a pair of organs that constantly clean the blood. Your blood cycles through your kidneys about 350 times a day. Inside each kidney are nephrons, microscopic filters that remove waste from the blood. (especially urea)

17. Water In, Water Out The balance of fluids in the body is controlled by chemical messengers called hormones. Sweat and thirst Antidiuretic hormone (ADH)-signals the kidneys to make less urine Diuretics-cause the kidneys to make more urine

18. Urinary System Problems Bacterial infections-bacteria in the bladder; if spreads to kidneys, then permanent damage can be caused to nephrons Kidney stones-when salts and other wastes collect inside the kidneys and form stones; can interfere with urine flow Kidney disease-can be caused by damage to nephrons; dialysis used as treatment to filter blood