The Digestive System and Body Metabolism 14 The Digestive System and Body Metabolism

5. Small Intestine … c. Physiology-Functions Chemical Digestion Absorption i) Chemical digestion Source of enzymes: *Intestinal cells of microvilli (brush border): what nutrients digested? - *Pancreas– enzymes for nutrients: which ones? *Nutrients– broken down into: what subunits? (Fig. 14.3, or review Ch2 Biochemicals) - *Carbohydrates  - *Proteins  - *Fats  - Nucleic Acids 

ii) Emulsification of lipids with Bile: *Produced by: organ? *Stored in: organ? Bile components: Bile Salts, Pigments (from RBCs), Cholesterol, Phospholipids, … Bile is deposited in: organ? Function: iii) Absorption of Nutrients Subunits first absorbed by: Then most nutrients move into: - Fat components move into:

Bile duct and sphincter Accessory pancreatic duct Right and left hepatic ducts from liver Cystic duct Common hepatic duct Bile duct and sphincter Accessory pancreatic duct Pancreas Gallbladder Jejunum Duodenal papilla Hepatopancreatic ampulla and sphincter Main pancreatic duct and sphincter Duodenum Figure 14.6

a. ANATOMY 6. Large Intestine Diameter & Length: ? Location: ? No villi present Goblet cells produce mucus for: b. *Subdivisions: List Colon Ascending, Transverse, & Descending Appendix Cecum Sigmoid

Large Intestine Anatomy … i) Appendix *Structure & Shape: ? lymphatic tissue *Medical Problem: ? ii) Colon *Parts: list Function iii) Rectum & Anus—inferior opening

B. Accessory Digestive Organs *Teeth: overall function 2. Salivary Glands a. Major Saliva composition: Mucus and serous fluids *b. Enzyme: Functions

Bile duct and sphincter Accessory pancreatic duct Right and left hepatic ducts from liver Cystic duct Common hepatic duct Bile duct and sphincter Accessory pancreatic duct Pancreas Gallbladder Jejunum Duodenal papilla Hepatopancreatic ampulla and sphincter Main pancreatic duct and sphincter Duodenum Figure 14.6

2. Pancreas *Location, Digestive Function: produces?, Organ that receives products: see small intestine *Endocrine Function– two hormones: what are they ? Duodenum Pancreas

3. Liver Liver a. *Location:, Digestive Function: produces what? See Small Intestine c. Other Functions *Produces plasma proteins which are put in blood plasma: which ones? Produces Cholesterol Produces Steroid Hormones Produces Urea from the break down of Amino Acids 4. Gall Bladder a. Shape/Structure: Sac under liver w/ duct b. *Function: ? c. Bile released when: Pancreas Gallbladder

Diaphragm Falciform ligament Liver Spleen Gallbladder Stomach Greater omentum Small intestine Large intestine Cecum (a) Figure 14.5a

III. Functions of the Digestive System-- Summarization Peristalsis A. Ingestion: Where and How? Swallowing Propulsion Peristalsis Segmentation B. Mechanical digestion- Where and How? Mouth Teeth Tongue Stomach

Functions of the Digestive System … C. Chemical digestion- Where and What? *Mouth: what nutrient Stomach: what nutrient Small Intestine: what nutrients D. Absorption- Where and What? *Small Intestine: what nutrients *Large Intestine: what nutrients E. *Defecation = By Rectum & Anus END