Small intestines, liver, gallbladder and pancreas - being very long so there is a large area over which absorption can take place (MP1). Containing villi, which increases the surface area for absorption (MP2). Villus epithelial cells having microvilli, which increases (MP3). Having thin, permeable walls and so a short diffusion distance. Having a rich capillary network, maintaining a high concentration gradient between the villi and the blood allowing the absorption of glucose and amino acids
