SMALL INTESTINE :
Length = 6.25m ( or 20 ft)
Diameter = 2.5cm
Parts-
1. Duodenum=25cm
2. Jejunum=2.4m
3. Ileum=3.6m
1.) Duodenum :-
- C-shaped
- It is the widest and shortest part of small intestine.
- Recieve the opening of hepatopancreatic duct.
- Mainly involve in neutralisation of acidic chyme.
2.) Jejunum :-
It is the middle part and is about 8 ft long.
3.) Ileum :-
- It is longest part of small intestine.
- Small intestine is the main reason where digestion and absorption of food occurs
LARGE INTESTINE :
- Length = 1.5 m ( 5 ft )
- Diameter = 7.5 m
- parts :- (i) Caecum
(ii) Colon
(iii) Rectum
Caecum :
- Last part of small intestine(i.e. ileum) opens into it and opening is guarded by ileocaecal valve.
- Finger like projection from Caecum = vermiform appendix
- Caecum and vermiform appendix = Vestigial ( first involved in cellulose digestion).
Colon :
- Divided into four parts : Ascending, transverse, descending and sigmoidal colon.
- Initial part of ascending colon has symbiotic E. Coli which synthesise vitamin b1, b3, b12 and k.
Rectum :
- Sac like structure used for storing faeces.
- The opening of rectum outside body is called anus.
- Anus is guarded by first internal involuntary anal sphincter and second is external voluntary anal sphincter.
- Inflammation of blood vessels in anorectal canal is called Haemorrhoids/piles.
NOTE :- Inflammation of appendix is appendicitis.