Digestive System Study Guide

Digestive System Study Guide

Structures of the Digestive System:
Mouth:
- Mechanical and initial chemical digestion.
- Mucus and saliva aid in breaking down food.
Pharynx:
- Common passage for food and air.
Esophagus:
- Transports food from the mouth to the stomach.
- Peristalsis aids in moving food through the esophagus.
Stomach:
- Storage and initiation of chemical digestion.
- Gastric acid kills bacteria, denatures proteins, and activates digestive enzymes.
Small Intestine:
- Main site of digestion and absorption.
- Composed of duodenum, jejunum, and ileum.
- Coiled structure with folds for increased surface area.
Large Intestine:
- Contains cecum, colon, and rectum.
- Absorbs water, electrolytes, and vitamins.
- Rectum stores feces until elimination.
Accessory Organs:
Teeth: Mechanical breakdown of food.
Tongue: Helps in swallowing and mixing food with saliva.
Salivary Glands: Produce saliva containing enzymes for chemical digestion.
Liver:
- Produces bile.
- Bile aids in fat digestion in the small intestine.
Gallbladder: Stores and releases bile.
Pancreas:
- Produces digestive enzymes and hormones.
- Enzymes aid in digestion, and hormones like insulin and glucagon regulate blood sugar.
Enzymes and Hormones:
Gastrin:
- Produced by the stomach.
- Stimulates stomach acid production.
Cholecystokinin (CCK):
- Produced in the small intestine.
- Stimulates enzyme release from the pancreas and bile from the liver.
Secretin:
- Produced in the small intestine.
- Stimulates bicarbonate production by the pancreas.
Insulin:
- Produced in the pancreas.
- Regulates blood sugar levels by facilitating glucose uptake.