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

CH 14 THE DIGESTIVE SYSTEM I. Overview Of The Digestive System *Function: B. Major Processes Ingestion, Digestion, Absorption, and Defecation C. Organs *Alimentary Canal define & list organs *Accessory Digestive Organs define & list organs Sphincters

Mouth (oral cavity) Parotid gland Tongue Sublingual gland Salivary glands Submandibular gland Pharynx Esophagus Stomach Pancreas (Spleen) Liver Gallbladder colon Transverse Duodenum Descending colon Small intestine Jejunum lleum Ascending colon Large intestine Cecum Sigmoid colon Rectum Appendix Anus Anal canal Figure 14.1

II. Organs of the Digestive System A. Alimentary Canal Organs. 1 II. Organs of the Digestive System A. Alimentary Canal Organs 1. Mouth (Oral Cavity) Uvula a. Anatomy *Oral cavity proper define *Uvula define - Function *Tongue define Teeth Tonsils Tonsils

b. Mouth Physiology *Masticated (mastication): define Mixing with saliva Swallowing: Function of Uvula, Tongue, Pharynx iii) Taste iv) Chemical Digestion: Enzyme: Amylase + Starch Glucose + Glucose …

2. Pharynx a. Anatomy: Review Nasopharynx Hard palate Soft palate Oral cavity Uvula Lips (labia) Palatine tonsil Vestibule Lingual tonsil Oropharynx Lingual frenulum Epiglottis Tongue Laryngopharynx Hyoid bone Esophagus Trachea (a)

b. Pharynx Physiology 1. *Substances that move through the Pharynx: 2. Subdivides into: Larynx and Esophagus 3. How keep food out of Lungs– *Epiglottis of the Larynx– see Respiratory system Larynx Esophagus

3. Esophagus Anatomy *Length: b. *Location: c.* Function: Esophagus

4. Stomach a. Anatomy *Location: *Shape *Amount of food it can hold: Cardioesophageal Sphincter *Location: *Shape *Amount of food it can hold: *Rugae Sphincters Cardioesophageal Pyloric Smooth muscle in Walls– 3 layers Inner layer: type of tissue = Mucus Microscopic- Gastric Glands Secrete: Pyloric Sphincter Rugae Gastric Glands

Fundus Body Rugae of mucosa Pyloric (b) Pyloric sphincter antrum Figure 14.4b

b. Stomach Physiology/Functions Temporary storage Physical Breakdown *Intrinsic Factor function iv) Digestion of Proteins Gastric Juice contains: - Hydrochloric Acid (HCl): Pepsinogen: Pepsin: activated form of enzyme Pepsinogen; activated by HCl Chief Cells Parietal Cells Pepsinogen Gastric Glands Pepsin HCl

Pepsin … Pepsin digests Proteins into its subunits, Amino Acids Pepsin + Proteins Amino Acids + A.A. …

Smooth Muscle: two layer *Major Parts: list (3) Inner folds Function 5. Small Intestine Gross View a. Anatomy i) Gross (1) *Shape & Length: Smooth Muscle: two layer *Major Parts: list (3) Inner folds Function ii) Microscopic Anatomy (1) Tissue of Lining: (2) *Villi: describe Blood vessels *Lacteal: define Muscle Layers Villi Circular Folds Microscopic view of Villi Lacteal

Microvilli (brush border) (c) Absorptive cells Absorptive cells Lacteal Villus Blood capillaries Lymphoid tissue Intestinal crypt Muscularis mucosae Venule Lymphatic vessel (c) Absorptive cells Submucosa (b) Villi Figure 14.7b

ii) Microscopic Anatomy … *Microvilli define Function b. Special Functions of the Duodenum i) Location ii) Two Adjacent Accessory Organ: iii) Substances received Pancreas: Pancreatic Duct Liver: Bile Duct Microvilli on a cell Liver & Bile Duct Duodenum Pancreas & Pancreatic Duct

END

Cardioesophageal sphincter Fundus Esophagus Muscularis externa Serosa • Longitudinal layer • Circular layer Body • Oblique layer Lesser curvature Rugae of mucosa Pylorus Greater curvature Duodenum Pyloric Sphincter (valve) Pyloric antrum (a) Figure 14.4a