### **Main Components of the Human Digestive System and Their Functions**

1. **Mouth**  
   - **Function**: Mechanical digestion (chewing) and chemical digestion (saliva contains amylase to begin carbohydrate breakdown).  
   - **Problems**: Tooth decay, gum disease, dry mouth (xerostomia), difficulty swallowing (dysphagia).

2. **Esophagus**  
   - **Function**: Transports food to the stomach via peristalsis.  
   - **Problems**: Acid reflux (GERD), esophagitis, and esophageal strictures.

3. **Stomach**  
   - **Function**: Secretes gastric juices (HCl and enzymes) to digest proteins; churns food into chyme.  
   - **Problems**: Gastritis, ulcers, acid reflux, and stomach cancer.

4. **Small Intestine** (Duodenum, Jejunum, Ileum)  
   - **Function**: Most digestion and nutrient absorption occur here; bile and pancreatic enzymes assist.  
   - **Problems**: Celiac disease, Crohn's disease, infections, and malabsorption syndromes.

5. **Liver**  
   - **Function**: Produces bile to help digest fats; detoxifies blood; stores vitamins and glycogen.  
   - **Problems**: Hepatitis, cirrhosis, fatty liver disease, and liver cancer.

6. **Gallbladder**  
   - **Function**: Stores and releases bile into the small intestine to aid in fat digestion.  
   - **Problems**: Gallstones, cholecystitis, and bile duct obstruction.

7. **Pancreas**  
   - **Function**: Produces digestive enzymes (amylase, lipase, proteases) and hormones (insulin, glucagon).  
   - **Problems**: Pancreatitis, diabetes, and pancreatic cancer.

8. **Large Intestine (Colon)**  
   - **Function**: Absorbs water and electrolytes; forms and stores feces.  
   - **Problems**: Constipation, diarrhea, diverticulitis, irritable bowel syndrome (IBS), and colorectal cancer.

9. **Rectum and Anus**  
   - **Function**: Stores and expels feces through defecation.  
   - **Problems**: Hemorrhoids, anal fissures, and rectal prolapse.

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### **Summary of Common Digestive System Problems**
- **Inflammatory Disorders**: Celiac disease, Crohn's disease, and ulcerative colitis.
- **Infections**: Gastroenteritis (caused by bacteria, viruses, or parasites).
- **Functional Disorders**: IBS, acid reflux, and dyspepsia.
- **Structural Issues**: Hernias, diverticula, and strictures.
- **Malignancies**: Cancers of the stomach, colon, liver, pancreas, and esophagus.
- **Nutritional Problems**: Malabsorption syndromes, vitamin deficiencies, and anorexia.

Maintaining a balanced diet, hydration, and healthy lifestyle can reduce the risk of many digestive problems.