Gastrointestinal System
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The gastrointestinal (GI) system digests food and makes nutrients available to the body. It begins breaking down food in the mouth through enzymes and moves food through the digestive tract using peristalsis. Various organs like the stomach, small intestine, and large intestine further break down food using enzymes, acids, and bacteria before absorbing nutrients and expelling waste. The GI system communicates with the nervous system to regulate hunger, digestion, and nutrient feedback loops.
Gastrointestinal System
- 1. Gastrointestinal System (Digestive System)
- 2. Purpose Main Function: Digest food and make nutrients available for the rest of the body.
- 3. Feedback loops Muscles use energy Brain tells GI system to Brake down food faster and make more energy available. You feel “Hungry” Need to replace used energy stores.
- 4. Mouth Digestion begins Saliva - Enzymes Mastication Prepares food for next voyage
- 5. Peristalsis Muscular contraction in the GI system that moves food through the body Reverse Peristalsis: when food comes back out.
- 6. Esophagus Tube that leads from Mouth to Stomach. Lined with involuntary muscles No digestion or absorption takes place here.
- 7. Epiglottis
- 8. Stomach Begins chemical digestion More enzymes and acids Low pH levels, kill off bacteria Mechanical digestion Churning, squeezing
- 9. Heartburn The heart is not involved. When acid from stomach travels up the esophagus. Esophagus is not protected from acid, and it begins to burn the lining of muscle.
- 10. Small Intestine 22 feet long! Further breakdown of food with bile. Begins nutrient absorption. 3 Parts Duodenum Jejunum Ileum
- 11. Villi Wrinkles in lining of small and large intestine Purpose: Increase surface area Microvilli: each villus is covered in even smaller wrinkles Purpose: Increase surface area
- 12. Large Intestine Most responsible for absorption Water from indigestible food Any nutrients the SI didn’t get Rectum stores waste to be expelled through anus.
- 13. Summary The GI system plays an important role in our bodies. It provides the rest of the body with nutrients and energy. It connects with the nervous system to inform us of when to eat. The nervous system can also inform the GI system to prepare for incoming food.