Digestion SI Movement The Ileocecal valve Anatomy of

Digestion SI Movement The Ileocecal valve Anatomy of the LI LI functions Bowel Motility Marieb 23

Absorption in the SI 10 -12 L 1200 ml 99% Nutrients 80% electrolytes and H 2 O

Small Intestine Motility: Segmentation Duodenum 12 -14/min Ileum 8 -9/min

Small Intestine Motility: Peristalsis Migratory Motor Complex Process repeats itself twice

Opening the Ileocecal Valve/Sphincter 1) Gastrin 2) Gastroileal reflex Active stomach Segmentation of the ileum Sphincter opens

Origin of the Feces: Large Intestine Anatomy

Large Intestine: Digestion and Absorption 12 -24 hours Bacterial flora Absorption of water, Na, Cl 1000 ml 150 ml

Large Intestine: Muscularis Externa Teniae Coli “Ribbons of the Colon” Haustra (pl. ) Hastrum (s)

Large Intestine Mucosa Simple Columnar Epithelium No Digestive enzymes No villi, microvilli Crypts

Crypts of the Large Intestine Goblet Cells Mucus aids feces movement Protection from acid and gas

Bacterial Flora Ferment indigestible carbs B complex vitamins Vitamin K

The Ileum protects itself from LI Flora Peyer’s Patches

Bowel Motility Mostly Inactive Slow haustral Contractions Mass Movement/ Mass Peristalsis Gastrocolic Reflex

Rectum Internal sphincter: Involuntary Anal Canal External sphincter: Voluntary

Defecation Reflex Spinal Cord Reflex Involuntary and Voluntary Components