State 4 adaptation for the ileum for absorption

Here are four adaptations of the ileum for absorption:

1. Large Surface Area: The inner lining of the ileum has folds, villi, and microvilli, which vastly increase the surface area available for absorption.
2. Thin Walls: The walls of the villi are only one cell thick (epithelial cells), creating a short diffusion distance for nutrients.
3. Rich Blood Supply: Each villus contains a dense network of capillaries that quickly transport absorbed nutrients (like glucose and amino acids) away, maintaining a steep concentration gradient.
4. Presence of Lacteals: Each villus also contains a lacteal (a lymphatic vessel) that absorbs digested fats (fatty acids and glycerol) and transports them into the lymphatic system.