The Digestive and Endocrine Systems Ch. 35

Feed Me! Digestive system uses mechanical and chemical energy to break organic material Digestive system uses mechanical and chemical energy to break organic material Material is absorbed into the cells of our bodies; used to make energy or other molecules Material is absorbed into the cells of our bodies; used to make energy or other molecules Mechanical: Mechanical: – Grinding, smashing tearing, crushing Chemical: Chemical: – Enzymes and Acidic solutions

The Mouth: Mechanical Chewing: Chewing: – Tearing and grinding food into small lumps; increase surface area for enzyme activity Teeth: Teeth: – Strongest bones in the body – Incisors; cutting food – Cuspids; tearing food – Molars; grinding food Tongue: Tongue: – Strongest muscle in the body – Pushes food down esophagus

The Mouth: Chemical Amylase: Amylase: – Enzyme that breaks down starch into di and monosaccharaides Taste buds: Taste buds: – Alert us to nutrients we need to consume – Sugar  Sweet – Acids  Sour – Toxins  Bitter – Salts  Salty – Protein  Umami Tonsils: Tonsils: – Protect body from bacteria take in through the mouth and nose

The Esophagus Swallowing pushes food down the esophagus to the stomach Swallowing pushes food down the esophagus to the stomach Peristalsis: Peristalsis: – Contractions of muscle waves move food in one direction Food has to pass by the trachea (entrance to the lungs) so a small cartilage cover (epiglottis) blocks the opening Food has to pass by the trachea (entrance to the lungs) so a small cartilage cover (epiglottis) blocks the opening Eating too fast can send food “Down the Wrong Pipe” Eating too fast can send food “Down the Wrong Pipe”

The Stomach: Mechanical Walls of stomach contract to crush food and help mix food with digestive juices Walls of stomach contract to crush food and help mix food with digestive juices

The Stomach: Chemical Glands in stomach release Pepsin and HCl Glands in stomach release Pepsin and HCl Pepsin breaks down proteins into amino acids Pepsin breaks down proteins into amino acids HCl keeps the stomach at a pH 2! HCl keeps the stomach at a pH 2! Food can take up to 4 hours to digest Food can take up to 4 hours to digest Why doesn’t HCl eat through the stomach? Why doesn’t HCl eat through the stomach? – Lining of stomach makes protective mucus

Heart Burn and Stomach Ulcers “Heart Burn” is when stomach acid gets into the esophagus and causes a burning feeling in the chest “Heart Burn” is when stomach acid gets into the esophagus and causes a burning feeling in the chest Caused by spicy food Caused by spicy food Stomach Ulcer is a hole in the stomach lining which can cause major health problems Stomach Ulcer is a hole in the stomach lining which can cause major health problems Caused by high acidic levels Caused by high acidic levels

The Small Intestine: Mechanical 6 m long but only 2.5 cm wide 6 m long but only 2.5 cm wide Peristaltic contractions move food through intestine and continue to break down food Peristaltic contractions move food through intestine and continue to break down food Food is absorbed into the blood through villus Food is absorbed into the blood through villus

The Small Intestine: Chemical 3 pronged attack in the Duodenum (first 25cm) 3 pronged attack in the Duodenum (first 25cm) – Pancreas releases enzymes to break down carbohydrates, proteins, and fats – Liver releases “Bile” which breaks down fats – Gallbladder releases extra bile to break large fat groups into small drops

The Large Intestine Only 1.5m long but 6.5cm wide Only 1.5m long but 6.5cm wide Indigestible material is compacted as much water as possible is absorbed back into the body Indigestible material is compacted as much water as possible is absorbed back into the body Anaerobic bacteria produce vitamins B and K for us while digesting the material Anaerobic bacteria produce vitamins B and K for us while digesting the material After hours, waste is removed from the body as feces After hours, waste is removed from the body as feces Passes through the last part of the digestive system, the rectum (the butt) Passes through the last part of the digestive system, the rectum (the butt)

Homework Ch. 35 workbook Ch. 35 workbook Group Presentation: Group Presentation: – Each group will present on a vital nutrient – Use a ppt, images, videos, live demonstrations, etc… – Each group must explain: Why is their nutrient important to the body Why is their nutrient important to the body How does it keep us healthy How does it keep us healthy How much should we consume each day How much should we consume each day Where can we get this nutrient from Where can we get this nutrient from Each group must supply me with 3 quiz questions on their nutrient. I may use these to create your next quiz. All group members must speak! Give me your PPT by next Friday so I can check they work on my PC!!