Topic: Digestive System Aim: Describe the parts and functions of the digestive system. Do Now: Take out the Chemistry homework sheet. HW: Ditto Midterm Review: Cells (both sides) Food Label Activity due Tuesday! Did you know.... Americans eat about 700 million pounds of peanut butter. Americans eat over 2 billion pounds of chocolate a year. In your lifetime, your digestive system may handle about 50 tons!! What you ate for breakfast, that was not digested will come out in about 48 hours-normally. From intake to outlet, the digestive tract is about thirty feet long. Function Breakdown of food into pieces small enough for nutrients to diffuse into cells Path of Food 1.Mouth (oral cavity) TEETH Incisors Canine Premolars Molars Wisdom tooth Tongue Salivary glands Opening of a salivary gland duct Mechanical digestion (teeth) These glands may become swollen and painful if you develop certain conditions, such as mumps Chemical digestion (STARCH) Salivary glands secrete saliva Did you know.... We make 1 to 3 pints of saliva a day Your teeth started growing 3 months before you were even born. The hardest substance in your body is the enamel on your teeth. As you are sitting there listening, more than 100 million germs are swimming, feeding, reproducing, and making waste in the area behind your lips. In your mouth there are more living things than there are people in Australia and Canada combined 2. Epiglottis Small flap of tissue Covers windpipe when you swallow Prevents choking 3. Esophagus esophagus Tube that pushes food down into stomach by PERISTALSIS NO DIGESTION Did you know.... An adult esophagus ranges from 10 to 14 inches in length, and 1 inch in diameter Opening to stomach from the esophagus 4.Stomach Chemical digestion of proteins Mucus lining (protection) Did you know.... An adults stomach can hold approximately 1.5 liters of material. Food sloshing in the stomach can last 3-4 hours. The stomach's wall is lined with three layers of powerful muscles. Topic: Digestive System Aim: Describe the parts and functions of the digestive system. Do Now: Take out the Chemistry homework sheet and cell homework sheet. HW: Ditto Cell Transport and Respiration Food Label Activity due Tuesday! 5.Small intestineh.org/misc/mo vie/bodybasic s/digestive_sy stem.html Length = 4-7 meters Duodenum first part of the SI Where MOST chemical digestion occurs Digestion ENDS here Lined with VILLI: folds that absorb nutrients into the blood 6.Large intestine The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, rebooting the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past. Surgical removal of the appendix causes no observable health problems. &NR=1 NO DIGESTION Absorption of water Forms feces (undigested food ) If you squeezed out all of the bacteria that lives in your intestines, you could almost fill up a coffee mug. Anyone want a sip? Did you know.... Within the colon, a typical person harbors more than 400 distinct species of bacteria. 7.Rectum Last part of large intestine Stores feces 8.Anus Where feces is egested out of the body