Final answer:
The three segments of the small intestine, responsible for digestion and absorption of nutrients, are the duodenum, jejunum, and ileum; with the duodenum starting the process and the ileum being the final part before the large intestine.
Step-by-step explanation:
The small intestine is a vital organ in the digestive system, where most of the digestion and absorption of nutrients takes place. It is divided into three consecutive segments: duodenum, jejunum, and ileum.
The duodenum is the first section that receives the partially digested food from the stomach. It plays a crucial role in the chemical digestion process. Moving forward, the mid-section is the jejunum, which is responsible for the bulk of nutrient absorption. Lastly, the ileum is the final segment, where the remaining nutrients are absorbed before the contents move into the large intestine.
The small intestine, with its elaborate structure consisting of villi and microvilli, maximizes its surface area to efficiently absorb nutrients. Its environment is further enhanced by the addition of pancreatic juice and intestinal juice, which together provide the necessary conditions for the digestion and absorption processes. The segmentation movement of the small intestine aids in thoroughly mixing the content, further facilitating the absorption of nutrients.