ELAINE N. MARIEB EIGHTH EDITION 14 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Digestive System and Body Metabolism

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 1.Oral Cavity 2.Salivary Glands 3.Pharynx 4.Trachea 5.Esophagus 6.Stomach 7.Duodenum 8.Jejunum 9.Ileum 10.Cecum 11.Appendix 12.Ascending Colon 13.Transverse Colon 14.Descending Colon 15.Sigmoid Colon 16.Rectum 17.Anus 18.Liver 19.Gall Bladder 20.Pancreas

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Digestive System and Body Metabolism  Digestion  Breakdown of ingested food  Absorption of nutrients into the blood  Metabolism  Production of cellular energy (ATP)  Constructive and degradative cellular activities

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Organs of the Digestive System  Two main groups  Alimentary canal – continuous coiled hollow tube  Accessory digestive organs

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Organs of the Digestive System Figure 14.1

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oral Cavity (Mouth) Anatomy  Lips (labia) – protect the anterior opening  Cheeks – form the lateral walls  Hard palate – forms the anterior roof  Soft palate – forms the posterior roof  Uvula – fleshy projection of the soft palate Figure 14.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Mouth (Oral Cavity) Anatomy  Vestibule – space between lips externally and teeth and gums internally  Oral cavity – area contained by the teeth  Tongue – attached at hyoid and styloid processes of the skull, and by the lingual frenulum Figure 14.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Mouth (Oral Cavity) Anatomy  Tonsils  Palatine tonsils  Lingual tonsil Figure 14.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Teeth  The role is to masticate (chew) food  Humans have two sets of teeth  Deciduous/baby teeth  20 teeth are fully formed by age two  Permanent (32 including 3 rd molars)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Processes of the Mouth  Mastication (chewing) of food  Mixing masticated food with saliva  Initiation of swallowing by the tongue  Allowing for the sense of taste

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Pharynx Anatomy  Nasopharynx – not part of the digestive system  Oropharynx – posterior to oral cavity  Laryngopharynx – below the oropharynx and connected to the esophagus Figure 14.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pharynx Function  Serves as a passageway for air and food  Food is propelled to the esophagus by two muscle layers  Food movement is by alternating contractions of the muscle layers (peristalsis)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Esophagus  Runs from pharynx to stomach through the diaphragm  Conducts food by peristalsis (slow rhythmic squeezing)  Passageway for food only (respiratory system branches off after the pharynx)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Layers of Alimentary Canal Organs Figure 14.3

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Activities of the Pharynx and Esophagus  These organs have no digestive function  Serve as passageways to the stomach

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Anatomy  Located on the left side of the abdominal cavity  Food enters at the cardioesophageal sphincter  A ring of smooth muscle fibers at the junction of the esophagus and stomach.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Anatomy  Regions of the stomach  Cardiac region – near the heart  Fundus – means top  Body  Pylorus – funnel-shaped terminal end  Food empties into the small intestine at the pyloric sphincter

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lesser curve 9 Greater curve

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Anatomy  Rugae – internal folds of the mucosa  External regions  Lesser curvature  Greater curvature

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Anatomy  Layers of peritoneum attached to the stomach  Lesser omentum – attaches the liver to the lesser curvature  Greater omentum – attaches the greater curvature to the posterior body wall  Contains fat to insulate, cushion, and protect abdominal organs

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Anatomy Figure 14.4a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Functions  Acts as a storage tank for food  Site of food breakdown  Chemical breakdown of protein begins  Delivers chyme (processed food) to the small intestine

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stomach Videos  Stomach Digestion Animation Stomach Digestion Animation  Camera Pill to Stomach Camera Pill to Stomach

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Small Intestine  The body’s major digestive organ  Site of nutrient absorption into the blood  21 feet long

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Duodenum  Attached to the stomach  Curves around the head of the pancreas  First inches  Jejunum  Attaches anteriorly to the duodenum  Top 2/5 of the small intestine- 8 ft long  Ileum  Extends from jejunum to large intestine  12 ft long Subdivisions of the Small Intestine

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Digestion in the Small Intestine  Source of enzymes that are mixed with chyme  Intestinal cells  Pancreas  Bile enters from the gall bladder

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Digestion in the Small Intestine Figure 14.6

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Folds of the Small Intestine  Called circular folds  Deep folds of the mucosa and submucosa  The submucosa has Peyer’s patches (collections of lymphatic tissue)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Villi of the Small Intestine  Fingerlike structures formed by the mucosa  Give the small intestine more surface area Figure 14.7a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microvilli of the Small Intestine  Small projections of the plasma membrane  Found on absorptive cells Figure 14.7c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures Involved in Absorption of Nutrients  Absorptive cells  Blood capillaries  Lacteals (specialized lymphatic capillaries) Figure 14.7b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Small Intestine In Action  Small Intestine Physiology Small Intestine Physiology  Digestion at work ( also fatty liver disease and irritable bowel) Digestion at work ( also fatty liver disease and irritable bowel)

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Large Intestine  Larger in diameter, but shorter than the small intestine  Frames the internal abdomen

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Large Intestine  Absorption of water  Eliminates indigestible food from the body as feces  Does not participate in digestion of food  Goblet cells produce mucus to act as a lubricant

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Large Intestine  Cecum – saclike first part of the large intestine  Appendix  Accumulation of lymphatic tissue that sometimes becomes inflamed (appendicitis)  Hangs from the cecum

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Large Intestine  Colon  Ascending  Transverse  Descending  Sigmoid  Rectum  Anus – external body opening  Colonoscopy video- removing a polyp Colonoscopy video- removing a polyp

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Questions  Describe the pathway of structures in the alimentary canal.  Include functions and important structures.  Ex: teeth in oral cavity; villi in small intestine

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings ACCESSORY STRUCTURES

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Saliva  Produced by salivary glands near oral cavity  Mixture of mucus and serous fluids  Helps to form a food bolus  Contains salivary amylase to begin starch digestion  Dissolves chemicals so they can be tasted

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pancreas  Produces a wide spectrum of digestive enzymes that break down all categories of food  Enzymes are secreted into the duodenum  Alkaline fluid introduced with enzymes neutralizes acidic chyme  Endocrine product of pancreas  Insulin - hormone which has extensive effects on metabolism and other body functions

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Liver  Largest gland in the body  Located on the right side of the body under the diaphragm  Consists of four lobes suspended from the diaphragm and abdominal wall  Connected to the gall bladder via the common hepatic duct  Stores fat, glycogen, iron, and certain minerals, and detoxifies certain chemicals

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bile  Produced by cells in the liver  Composition  Bile salts  Bile pigment- mostly bilirubin (from the breakdown of hemoglobin)  Cholesterol  Phospholipids  Electrolytes

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gall Bladder  Sac found in hollow fossa of liver  Stores bile from the liver  Bile is secreted into the duodenum in the presence of fatty food  Gallstones can cause blockages

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gallstones  Small, pebble-like substances and forms when bile is stored in the gallbladder hardens into pieces of stone-like material  The two types: cholesterol stones (80%) and pigment stones made of bilirubin.  Can be small as a grain of sand or as big as a golf ball.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 6 Processes of the Digestive System 1.Ingestion – getting food into the mouth

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Processes of the Digestive System  Peristalsis – alternating waves of contraction  Segmentation – moving materials back and forth to aid in mixing Figure Propulsion – moving foods from one region of the digestive system to another

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 6 Processes of the Digestive System 3.Mechanical digestion  Mixing of food in the mouth by the tongue  Churning of food in the stomach  Segmentation in the small intestine

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 6 Processes of the Digestive System 4.Chemical Digestion  Enzymes break down food molecules into their building blocks  Each major food group uses different enzymes  Carbohydrates are broken to simple sugars  Proteins are broken to amino acids  Fats are broken to fatty acids and alcohols

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 6 Processes of the Digestive System 5Absorption  End products of digestion are absorbed in the blood or lymph  Food must enter mucosal cells and then into blood or lymph capillaries 6.Defecation  Elimination of indigestible substances as feces

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Processes of the Digestive System Figure 14.11

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Questions  Identify the major functions of the three accessory organs.  Compare and contrast chemical and mechanical digestion.  Also identify which structures do each.

ELAINE N. MARIEB EIGHTH EDITION 14 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A Digestive System Disease and Disorders

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gingivitis  Gum Inflammation  Can lead to periodontitis (gum disease)  Destruction of gingiva and bone tissue  Causes:  Hormonal changes  Illnesses  Medications  Poor hygiene  Smoking  Family History

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oral Cancer  Cancer in any part of oral cavity  Lips, gums, tongue, cheeks, roof, floor  Symptoms: Pain or lumps in mouth  Causes  Genetic  Tobacco  Excessive alcohol  Excessive sun exposure (lips)  STD- human papillomavirus

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Peptic Ulcers  Open sore in lining of esophagus, stomach or duodenum  Common symptom: burning abdominal pain  Three types:  Gastric- stomach  Esophageal  Duodenal  Causes: bacterial infection, medication

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Acid Reflux  Acid from stomach gets into esophagus  Causes burning sensation  Once in a while= heartburn  More than twice a week= acid reflux  Causes:  Hiatal hernia= part of stomach gets above diaphragm (supposed to help keep acid in stomach)  Obesity  Large meals/ lying down after meal  Certain foods  Smoking

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Appendicitis  Appendix becomes inflamed and filled with pus  Lower right abdominal pain increases over hours  Begins near navel and shifts to lower right abdomen  Possible causes: obstruction or infection  Requires immediate attention!  A ruptured appendix can cause more infection

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Irritable Bowel Syndrome (IBS)  Functional gastrointestinal disorder- colon  Symptoms are caused by changes in how the GI tract works  Frequent symptoms without damage to GI tract  Symptom: Abdominal pain/discomfort along with changes in bowel habits  Treatment: control diet, lifestyle, and stress  Possible Causes:  Brain-gut signal problems  GI motor problems  Hypersensitivity  Mental Health Problems  Bacterial infection  Body Chemical Imbalance  Genetic  Food Sensitivity

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Crohn’s Disease  Inflammation of the lining of GI tract  Most common affected areas: ileum and colon  Symptoms:  Abdominal pain  Severe diarrhea  Malnutrition  Exact cause is unknown  Possibly heredity or immune system malfunction  Can lead to more serious complications such as ulcers, obstructions, and cancer

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Hemorrhoids  Swollen and inflamed veins in anus and lower rectum  Symptoms:  Painless bleeding  Itching/ irritation  Cause: Increase in pressure in lower rectum  Half of adults age 50+ have symptoms