IMG_4890.jpeg

# Review of the Digestive System ## 1. The Digestive System The digestive system has the function of ingesting, processing, and absorbing food through the process of digestion. It's composed of: * **Digestive Tube:** This is a continuous tube made up of the mouth, pharynx, esophagus, stomach, and...

# Review of the Digestive System ## 1. The Digestive System The digestive system has the function of ingesting, processing, and absorbing food through the process of digestion. It's composed of: * **Digestive Tube:** This is a continuous tube made up of the mouth, pharynx, esophagus, stomach, and intestines. * **Glands:** A series of glands are involved in the process. ### Mouth * **Mouth:** The entrance to the digestive tract. * **Tongue:** A voluntary muscle that helps mix the food. * **Teeth:** Adults have 32 teeth, each with different shapes for their specific function; * **Crown:** The portion extending past the gumline. * **Neck:** The connecting part. * **Root:** The embedded part. * **Pulp:** The live part inside the tooth. ### Salivary Glands * **Salivary glands:** These glands open into the mouth. ### Pharynx * **Pharynx:** A tube shared by both the digestive and respiratory systems. Also serves as a passage for food to enter the esophagus ### Esophagus * **Esophagus:** A tube that carries food from the pharynx to the stomach. It ends at the cardiac sphincter (cardia). ### Stomach * **Stomach:** A sac formed from smooth muscles lined with mucus and glands. It has a sphincter to separate it from the esophagus (cardia) and intestines (pylorus). * **Gastric Juice:** Acidity in the stomach, containing hydrochloric acid (HCl), kills bacteria and activates digestive enzymes. ### Intestines * **Small Intestine:** A long tube divided into three parts: duodenum, jejunum, and ileum. * **Location/Length:** Approximately 6 meters long. * **Structure:** Lined with a protective membrane, the peritoneum. This part is mostly involved in absorption. * **Large Intestine:** A shorter tube divided into three parts: cecum, colon, and rectum. * **Location/Length:** Approximately 2 meters long. * **Structure:** Lined with a protective membrane, the peritoneum. This part is mostly involved in water reabsorption. ### Additional digestive components * **Liver:** Produces bile, which plays a key role in fat digestion. * **Pancreas:** Produces pancreatic juice, which helps neutralize stomach acid and contains enzymes for digesting carbohydrates, proteins, and fats. * **Bile:** Produced by the liver to aids in the digestion of fats. **Digestion stages:** * **Bolus:** The soft mass of food formed in the mouth. * **Chyme:** The processed food that enters the intestines. * **Chyle:** The nutrient-rich liquid that's absorbed from the intestines into the bloodstream.