The Digestive System How long is your digestive
- Slides: 15
The Digestive System
How long is your digestive system? Almost 9 meters or 30 feet!
The Digestive System • Breakdown (digestion) of foods into simpler molecules • Absorption of simple molecules into the blood for the cells of the body to use
Mechanical Digestion Physical Breakdown • Mouth – Chew food • Esophagus, Stomach, Intestines – Muscle contractions move food through the digestive system
Chemical Digestion Chemical Breakdown • Mouth – Salivary glands produce enzymes • Stomach – Food mixed with acids • Small Intestine – Enzymes break down food – Microvilli absorb food
The Route of Food through the Digestive System Mouth Esophagus Stomach Small Intestine Large Intestine Anus
The Route of Food Digestion 1. Food is chewed & mixes with saliva. 2. Food is swallowed & moves through the esophagus. 3. Food moves into the stomach.
The Route of Food Digestion 4. Food is broken down into a liquid paste as it’s mixed with acids. 5. Food moves into a long tube called the small intestine. 6. Nutrients are absorbed into the blood by the villi in the small intestine.
The small intestine is very efficient – almost all of the nutrients from your food are absorbed. • The lining of the small intestine is covered in tiny projections called villi. • The villi make absorption efficient by increasing the surface area of the small intestine. The small intestine is over 20 ft. long & has a surface area the size of a tennis court!
The Route of Food Digestion 7. Undigested food moves into the large intestine. 8. Water is removed from the undigested food. 9. Undigested liquid food paste is turned into solid waste. 10. Solid waste leaves the body through the anus.
Digestive System Diseases • Heartburn: caused by acid reflux from stomach back into esophagus & pharynx • Ulcers: caused by bacteria – the pain is the stomach acid irritating the stomach lining • Inflammatory Bowel Disease (IBD) – Inflammation of rectum, colon, & small intestine – Symptoms include fever, nausea, weight loss, diarrhea
Stomach Ulcer Inflammatory Bowel Disease