Large intestine

• Larger in diameter, shorter in length (15m) than small intestine
• Extends from the ileocecal valve to the anus
• Subdivisions:

  -Cecum

  -Appendix

  -Colon
• Cecum: saclike first part of large intestine
• Appendix: Hangs from the cecum
• Appendix: Accumulation of lymphoid tissue that sometimes becomes inflamed (appendicitis)
• Colon:

  -Ascending: travels up right side of abdomen and makes a turn at the right colic (hepatic) flexure
• Colon:

  -Transverse: travels across te abdomnal cavity and turns at the left colic (splenic) flexure
• Colon:

  -Desending: travels down the left side
• Colon:

  -Sigmoid: s-shaped region; enters the pelvis
• Anal canal ends at anus
• Anus: opening for large intestine
• Exernal anal sphincetr: formed by skeletal msucle and voluntary
• Internal anal sphincter: formed by smooth muscle and invouluntary
• External and Internal anal sphincters normally closed except duing defection
• Large intestine delivers indigestible food residues to the body exterior
• Goblet cells produce alkaline mucus to lubricate the passage of feces
• Muscularis externa layer is reduced to three bands of msucle (teniae coli)
• These bands of muscle cause the all to pucker into haustra (pocketlike sacs)
• Activities: nutrient breakdown and absorption
• Acivities: no digestive enzymes are produced
• Activities: resistent bacteria digest remaining nutrients:

  -Produce some vitamin K and some B vitiamins
• Activities: absorption of water, vitamins, and ions
• Activities: remaining materials are eliminated via feces
• Feces contain:

  -undigested food residues

  -mucus

  -bacteria

  -water
• feces


  Solid waste eliminated by the anus