The digestive system plays a crucial role in breaking down the food and drink we consume into essential nutrients that the body needs for energy, growth, and cell repair. It includes the gastrointestinal (GI) tract and solid organs like the liver, pancreas, and gallbladder. By breaking down proteins, fats, and carbohydrates into smaller molecules, the digestive system allows for the absorption of nutrients such as amino acids, fatty acids, and simple sugars. These nutrients support the body’s functions and overall health. Additionally, the digestive system regulates water absorption in the large intestine and converts waste products into stool for elimination. The system works in harmony with nerves, hormones, and gut bacteria to control and optimize digestion (National Institute of Diabetes and Digestive and Kidney Disease, 2017).
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––PANCREAS––

The pancreas is a large gland located in the abdomen that functions as part of the digestive and endocrine systems. It produces digestive enzymes that break down food in the small intestine and hormones like insulin and glucagon that regulate blood sugar levels. This helps maintain proper function of other organs such as the heart, liver, kidneys, and brain. Anatomically, the pancreas is situated behind the stomach and extends from the right side of the body near the small intestine to the left side near the spleen. It resembles a tadpole in shape, with a bumpy texture and a weight of approximately 91.8 grams (Cleveland Clinic, 2024).

––SMALL INTESTINE––

The small intestine is a part of the digestive system and is the primary site for digestion and nutrient absorption. It connects the stomach to the large intestine and is about 22 feet long, making it the longest part of the gastrointestinal (GI) tract. The small intestine is divided into three sections: the duodenum, jejunum, and ileum. The duodenum is the first section that receives food from the stomach and digestive juices from other organs. The jejunum continues digestion and begins nutrient absorption. The ileum is the final and longest section, where most water and nutrients are absorbed before food waste moves to the large intestine. The small intestine’s lining, with its folds and projections, provides a large surface area for efficient absorption of nutrients and water (Cleveland Clinic, 2021).

––LIVER––

The liver is a dark reddish-brown organ weighing about 3 pounds, located in the upper right-hand portion of the abdominal cavity beneath the diaphragm. It receives oxygenated blood from the hepatic artery and nutrient-rich blood from the hepatic portal vein, holding about one pint of the body’s blood supply at any given moment. The liver consists of two main lobes and produces bile, which aids in digestion and waste removal. It regulates blood chemical levels, produces proteins for blood plasma, cholesterol, and special proteins to carry fats. The liver converts excess glucose into glycogen for storage, regulates blood amino acids, and processes hemoglobin for its iron content. It also clears the blood of drugs and toxins, regulates blood clotting, resists infections, and clears bilirubin, preventing jaundice. Liver metabolism by-products are excreted via bile or blood, leaving the body as feces or urine (Johns Hopkins Medicine, n.d.).

––DUODENUM––

The duodenum is the first part of the small intestine and is C-shaped, located below the stomach. It consists of four segments: the superior, descending, transverse, and ascending parts, each performing different functions and facilitating the mixing of chyme with bile and pancreatic enzymes for digestion. The duodenum’s four layers include the mucosa, submucosa, muscularis externa, and serosal layers, each with specific roles in nutrient absorption, chemical digestion, and muscle contractions to move food along. The duodenum is a critical point of digestion where chyme is neutralized, mixed with digestive juices, and prepared for further nutrient absorption in the jejunum. It releases hormones like secretin and cholecystokinin for digestion and serves an immune function by acting as a barrier against harmful microbes (Christiansen, 2024).

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REFERENCES:

—-Christiansen, S. (2024, January 4). Duodenum: anatomy, location, and function. Verywell Health. https://www.verywellhealth.com/duodenum-anatomy-4780308

—-Cleveland Clinic. (2024, February 26). Pancreas. https://my.clevelandclinic.org/health/body/21743-pancreas

—-Cleveland Clinic. (2021, December 8). Small intestine. https://my.clevelandclinic.org/health/body/22135-small-intestine

—-Johns Hopkins Medicine. (n.d.). Liver: anatomy and functions. https://www.hopkinsmedicine.org/health/conditions-and-diseases/liver-anatomy-and-functions

—-National Institute of Diabetes and Digestive and Kidney Disease. (2017, December). Your digestive system & how it works. https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works