The ileum

The ileum

1. Serosa

   • Outer layer of tissue which provides support

2. Muscularis externa

   • Layer of longitudinal muscle and layer of circular muscle. Longitudinal contraction = pendular movement, circular contraction = local constrictions, helps churn food. Peristaltic waves puch food along (circular muscle)

3. Submucosa

   • Composed of connective tissue and contains blood vessels & lymphatic vessels

4. Muscularis mucosa

   • Thin layer of muscle responsible for the movement of the villi

5. Mucosa

   • Layer in contact with food in lumen, has adaption of villi and microvilli

6. The villus

   • Goblet Cells
     • Secrete Mucous in order to protective the microvilli from digestive enzymes
   • Columnar Epithelium
     • Adapted with extensions of their membrane (which contain enzymes) to form microvilli to give a brush border appearance
   • Paneth Cells
     • Anti-microbe protection for vulnerable stem cells
   • Crypts of Lieberkuhn
     • Glands which produce stem cells

Images and files in the map