What organ divided into three parts is where most digestion and absorption occurs
The correct answer and explanation is:
The correct answer is the small intestine.
The small intestine is divided into three main parts: the duodenum, the jejunum, and the ileum. It is the primary organ responsible for the majority of digestion and absorption of nutrients in the human body.
- Duodenum: This is the first section of the small intestine. It plays a crucial role in digestion by receiving bile from the liver and pancreatic enzymes from the pancreas. These digestive fluids help break down fats, proteins, and carbohydrates into smaller molecules. In this section, chemical digestion is completed.
- Jejunum: The second part of the small intestine, the jejunum, is primarily involved in the absorption of nutrients. The walls of the jejunum are lined with villi, tiny finger-like projections that increase the surface area for absorption. The nutrients from digested food, such as amino acids, sugars, fatty acids, vitamins, and minerals, are absorbed into the bloodstream through these villi.
- Ileum: The third and final section, the ileum, continues the absorption process, particularly absorbing vitamin B12, bile salts, and any remaining nutrients that were not absorbed in the jejunum. The ileum also has villi to assist with nutrient uptake.
The small intestine is highly efficient due to its large surface area, which is enhanced by the folds, villi, and microvilli on its inner lining. These features allow it to absorb a wide variety of nutrients from the food we eat. The absorbed nutrients are then transported via the bloodstream to various parts of the body for energy, growth, and repair. After the majority of digestion and absorption is complete in the small intestine, the remaining indigestible food passes into the large intestine for water absorption and eventual elimination.