* 2 colon
- 2.1 ascending colon
- 2.1.1 right coloic flexure (hepatic flexure)
- 2.1.2 12.5 cm long
- 2.1.3 extends from caecum to inferior surface of right lobe of liver
- 2.2 descending colon
- 2.2.1 25 cm long
- 2.2.2 left colic flx to sigmoid colon
- 2.2.3 runs vertically up to iliac crest
- 2.3 transverse colon
- 2.3.1 left colic flexure (splenic flexure )
- 2.3.2 50 cm long
- 2.3.3 suspended by transverse mesocolon
- 2.3.4 anteriorly related to greater omentum and anterior abd wall
- 2.3.5 posteriorly to 2nd part of duodenum
- 2.4 sigmoid colon( pelvic colon)
- 2.4.1 37.5 cm long
- 2.4.2 extends from pelvic brim to 3rd piece of sacrum
- 3 relevant features
- 3.1 wider in calibre
- 3.2 longitudinal muscle coat forms a thin layer ( पतली परत बनाते हैं )
- 3.2.1 3 ribbon like bands called taenia coli (
- taenia libera (
- placed anteriorly ( अग्र परत )
- ascending colon
- caecum
- sigmoid colon
- descending colon
- inferiorly
- transverse colon
- taenia mesocolica
- present on posteromedial surface
- ascending colon
- caecum
- sigmoid colon
- descending colon
- posteriorly
- transverse colon
- taenia omentalis
- posterolaterally
- ascending colon
- caecum
- sigmoid colon
- descending colon
- anteroposterior
- transverse colon
- 3.2.2 since taenia is shorter colon is puckered and sacculated
- 3.3 appendices epiploicae
- 3.3.1 small bags of peritoneum
- 3.3.2
- 3.4 blood supply of colon
- 3.5 lymph nodes
- 3.5.1 epicolic lymph nodes
- 3.5.2 paracolic lymph nodes
- 3.5.3 intermediate nodes
- 3.6 epithelium is absorptive (coloumnar ) but villi are absent
- 5 histology of colon
- 5.1 mucous membrane
- 5.1.1 invaginations called crypts of leiberkuhn
- 5.2 submucosa
- 5.2.1 meissners plexus
- 5.2.2 solitary lymphoid follicles
- 5.3 muscularis externa
- 5.3.1 outer longitudinal coat thickened to form
- taenia coli
- 5.3.2 inner coat is circular fibres
- 5.3.3 outermost layer is serous layer
Discussion