How is the Small Intestine Specialized for Absorption?
The small intestine is divided into the duodenum, jejunum, and ileum. Its mucosa is highly specialized for absorption through structures like villi and microvilli, which greatly increase the surface area. Key features include:
- Enterocytes: Absorptive cells with a brush border of microvilli. - Goblet cells: Secrete mucus for lubrication. - Paneth cells: Located at the base of crypts, these cells secrete antimicrobial peptides. - Brunner's glands: In the duodenum, these glands produce alkaline mucus to neutralize stomach acid.
