Large Intestine & Colon: Function, Anatomy & Location

Large Intestine & Colon: Function, Anatomy & Location

1. Large Intestine By Dr. Shereen Hamed Lecturer of Histology & Cell Biology Faculty of Medicine. Mansoura University

2. Large Intestine

3. Histological structure of the colon. Mucosa Submucosa Musculosa Serosa

4. 1) Mucosa It contains deep, more closely packed crypts (no villi ). It is formed of : Epithelium C.T corium Muscularis mucosa

5. A) Epithelium Simple columnar absorping cells. 2) Goblet cells: more numerous. 3) E.E. cells 4) Stem cells: at the base of crypt. 5) M-cells. 6) Caveolate cells.

6. B) C.T Corium: Markedly reduced by numerous deep crypts Solitary lymph nodules extend to submucosa C) Muscularis mucosa: Well developed Inner circular and outer longitudinal smooth layers.

7. Lymphocytic infiltration (no gland). Inner circular layer Outer longitudinal layer which breaks up into 3 bands called “ Taenia coli ” In the rectum: No taenia coli. 2) Submucosa 3) Musculosa

8. Loose C.T. + mesothelium Adipose C.T. accumulates under the peritoneum “appendices epiploicae ”. N.B: In the rectum, the serosa is replaced by adventitia. 4) Serosa

9. The Vermiform Appendix Microscopic appearance Mucosa Submucosa Musculosa Serosa

10. 1)Mucosa It shows crypts only but no villi . The crypts: fewer, narrow, shorter. Epithelium: 6 cells Fewer goblet cells

11. 1)Mucosa (b) Corium: Lymph follicles and diffuse lymphoid tissue forming circular layer (extend to the submucosa ). (c) Muscularis mucosa: It is ill defined

12. 2) Submucos a L oose C.T— lymph nodule . 3) Musculosa Thin . lnner circular . Outer longitudinal (no taenia coli). 4) S erosa Mesothelial layer. Submesothelial loose C.T

13. References Principles of histology, Semester 3 (student book of Histology & Cell Biology Department). Basic Histology, text book of histology & cell biology. https://ui-ex.com/explore/acini-clipart-pancreatitis/