Digestive System: Mouth and Esophagus

• The digestive system processes food and liquids.
• Its tract includes the mouth, esophagus, stomach, small and large intestines, and accessory organs.
• These organs break down food for absorption and assimilation.
• A person produces about 1 to 1.5 liters of saliva per day.
• Lesson objectives are to identify key components, explain digestion, absorption, and elimination, and describe the food journey from mouth to rectum.

Mouth

• It is the first organ in the digestive system.
• Food enters the mouth, the initial stage of digestion.
• Teeth break down large food into smaller pieces through chewing(mechanical digestion).
• Saliva begins chemical digestion by breaking down starch into sugar.

Esophagus

• It ensures the smooth movement of food from the mouth to the stomach.
• It facilitates efficient digestion and nutrient absorption.
• Unlike the stomach and small intestine, it does not secrete digestive enzymes.
• Its primary function is to facilitate the passage of food.

Stomach

• It is a hollow muscular organ.
• It holds food while mixing it with stomach enzymes.
• It temporarily stores food.
• It performs mechanical digestion through muscular contractions.
• It performs chemical digestion via acids and enzymes.
• It controls the emptying of partially digested food into the small intestine.

Pancreas

• It is located behind the stomach.
• It produces enzymes that break down sugars, fats, proteins, and starches during digestion.
• It releases hormones into the bloodstream.
• These hormones help regulate blood sugar levels, stimulate stomach acids, and control appetite and stomach emptying.

Liver

• It is the largest organ in the body and performs essential digestive functions.
• It continually produces bile, aiding fat digestion and nutrient absorption.
• It processes toxins and removes them from the blood.
• It creates substances necessary for blood clotting after injury.
• It helps maintain healthy blood sugar levels.

Gallbladder

• It is a small, pear-shaped organ located beneath the liver.
• It stores and concentrates bile produced by the liver.
• Bile is a sticky, yellow-green digestive fluid.
• Its primary function is to break down fats into fatty acids during digestion.

Small Intestine

• Its main functions include breaking down food, absorbing nutrients, and moving intestinal contents.
• It absorbs carbohydrates, proteins, and fats.
• It plays a vital role in digestion, ensuring efficient nutrient absorption and waste elimination.

Large Intestine

• It's also known as the colon.
• It follows the small intestine and extends to the anal canal, where food waste exits.
• It performs essential functions, such as absorbing water and electrolytes.
• It forms stool, facilitates bacterial fermentation, and protects against infections.

Rectum and Anus

• The rectum connects the large intestine to the anus.
• It acts as a reservoir where stool accumulates before elimination.
• The anus marks the exit point for food waste.
• Muscles, nerves, and mucous membranes facilitate healthy bowel movements.