Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 19 The Digestive System and Body

The Digestive System and Body Metabolism Slide 14.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Digestion  Breakdown of  Absorption  Passage of into the blood  Metabolism  Production of cellular energy ( )

Organs of the Digestive System Slide 14.2a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Two main groups  canal – continuous coiled hollow tube  Accessory digestive organs

Organs of the Digestive System Slide 14.2b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.1

Organs of the Alimentary Canal Slide 14.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings MPESSLAMPESSLA

Mouth (Oral Cavity) Anatomy Slide 14.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lips (l ) – protect the anterior opening  Cheeks – form the l  H palate – forms the anterior roof  Soft palate – forms the posterior  Uvula – fleshy projection of the s Figure 14.2a

Mouth (Oral Cavity) Anatomy Slide 14.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Vestibule – space between lips externally and and internally  Oral cavity – area contained by the  Tongue – attached at hyoid and processes of the skull, and by the lingual frenulum Figure 14.2a

Mouth (Oral Cavity) Anatomy Slide 14.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Tonsils  P  L Figure 14.2a

Processes of the Mouth Slide 14.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mastication ( ) of food  Mixing masticated food with  Initiation of swallowing by the  Allowing for the sense of

Pharynx Anatomy Slide 14.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  N not part of the digestive system  Oropharynx – posterior to oral  Laryngopharynx – below the oropharynx and connected to the Figure 14.2a

Pharynx Function Slide 14.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Serves as a passageway for and food  Food is propelled to the esophagus by two  Longitudinal layer  Circular layer  Food movement is by alternating contractions of the muscle layers ( )

Esophagus Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Runs from pharynx to stomach through the  Conducts food by peristalsis (slow squeezing)  Passageway for food only (respiratory system branches off after the pharynx)

Layers of Alimentary Canal Organs Slide 14.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  M  Innermost layer  M membrane  Surface  Small amount of tissue (lamina propria)  Small smooth

Layers of Canal Organs Slide 14.11b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Submucosa  Just the mucosa  Soft connective tissue with blood vessels, nerve endings, and

Layers of Alimentary Canal Organs Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Muscularis externa – smooth muscle  Inner  Outer  Serosa  Outermost layer – visceral  Layer of fluid-producing cells

Layers of Alimentary Canal Organs Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.3

Stomach Anatomy Slide 14.15a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Located on the left side of the cavity  Food enters at the cardioesophageal

Stomach Anatomy Slide 14.15b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Regions of the stomach  Cardiac region – near the  F  B  P – funnel-shaped terminal end  Food empties into the small intestine at the

Stomach Anatomy Slide 14.16a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  – internal folds of the mucosa  regions  Lesser curvature  Greater curvature

Stomach Anatomy Slide 14.16b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Layers of attached to the stomach  Lesser omentum – attaches the to the lesser curvature  Greater omentum – attaches the greater curvature to the body wall  Contains fat to, cushion, and protect abdominal organs

Stomach Anatomy Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.4a

Stomach Functions Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Acts as a for food  Site of food  Chemical breakdown of begins  Delivers (processed food) to the small intestine

Specialized of the Stomach Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Simple columnar  Mucous cells – produce a sticky alkaline mucus  glands – secrete gastric juice  Chief cells – produce protein-digesting enzymes ( )  Parietal cells – produce hydrochloric acid  Endocrine cells – produce

Structure of the Stomach Mucosa Slide 14.20a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Gastric pits formed by folded  Glands and specialized cells are in the

Structure of the Stomach Mucosa Slide 14.20b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.4b, c

Small Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The body’s major  Site of nutrient into the blood  tube extending form the pyloric sphincter to the ileocecal valve  Suspended from the posterior abdominal wall by the

Subdivisions of the Small Intestine “Dogs Just Itch! Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Duodenum  Attached to the  Curves around the head of the  Jejunum  Attaches anteriorly to the  Ileum  Extends from to large intestine

Chemical Digestion in the Small Intestine Slide 14.23a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Source of enzymes that are mixed with c  I  P  Bile enters from the

Chemical Digestion in the Small Intestine Slide 14.23b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.6

Villi of the Small Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Fingerlike structures formed by the  Give the small intestine more Figure 14.7a

Microvilli of the Small Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Small projections of the  Found on Figure 14.7c

Structures Involved in Absorption of Nutrients Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A  B  L (specialized lymphatic capillaries) Figure 14.7b

Folds of the Small Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Called circular folds or  Deep folds of the and submucosa  Do not disappear when filled with  The submucosa has Peyer’s patches (collections of )

Digestion in the Small Intestine Slide 14.57a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Enzymes from the border  Break double sugars into simple sugars  Complete some  Pancreatic enzymes play the major function  Help complete digestion of starch ( )  Carry out about half of all protein digestion (, etc.)

Digestion in the Small Intestine Slide 14.57b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pancreatic play the major digestive function (continued)  Responsible for fat digestion ( )  Digest nucleic acids ( )  Alkaline content neutralizes acidic

Absorption in the Small Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Water is absorbed along the length of the small intestine  End products of  Most substances are by active transport through cell membranes  are absorbed by diffusion  Substances are transported to the liver by the hepatic portal vein or

Propulsion in the Small Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  is the major means of moving food  Segmental movements  Mix chyme with  Aid in

Large Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Larger in diameter, but shorter than the small intestine  Frames the internal

Large Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.8

Functions of the Large Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Absorption of  Eliminates indigestible food from the body as  Does not participate in  cells produce to act as a lubricant

Structures of the Large Intestine Slide 14.30a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  C – saclike first part of the large intestine  Appendix  Accumulation of tissue that sometimes becomes inflamed (appendicitis)  Hangs from the

Structures of the Large Intestine Slide 14.30b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Colon  A  T  D  S-  Rectum  Anus –

Food Breakdown and Absorption in the Large Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  No digestive enzymes are produced  Resident bacteria digest remaining nutrients  Produce some vitamin K and B  Release gases  Water and vitamins K and B are absorbed  Remaining materials are eliminated via feces

Propulsion in the Large Intestine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sluggish  Mass movements  Slow, powerful movements  Occur  Presence of feces in the rectum causes a  Internal anal sphincter is  Defecation occurs with relaxation of the voluntary (external)

Accessory Digestive Organs Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings STPLGSTPLG

Salivary Glands Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Saliva-producing glands  P – located anterior to ears  S glands

Saliva Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mixture of  Helps to form a food  Contains salivary to begin starch digestion  Dissolves chemicals so they can be

Teeth Slide 14.35a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The role is to masticate ( ) food  Humans have two sets of teeth  D (baby or milk) teeth  20 teeth are fully formed by age

Teeth Slide 14.35b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Permanent teeth  Replace deciduous teeth beginning between the ages of  A full set is teeth, but some people do not have wisdom teeth

Classification of Teeth Slide 14.36a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings ICPMICPM

Classification of Teeth Slide 14.36b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.9

Regions of a Tooth Slide 14.37a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Crown – exposed part  Outer enamel  Dentin  Pulp cavity  Neck  Region in contact with the gum  Connects crown to root Figure 14.10

Regions of a Tooth Slide 14.37b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Root  Periodontal membrane attached to the bone  Root canal carrying blood vessels and nerves Figure 14.10

Pancreas Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Produces a wide spectrum of enzymes that break down all categories of food  Enzymes are secreted into the  Alkaline fluid introduced with enzymes neutralizes chyme  Endocrine products of pancreas  I  G

Liver Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  L gland in the body  Located on the right side of the body under the  Consists of four lobes suspended from the diaphragm and abdominal wall by the  Connected to the gall bladder via the common

Bile Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Produced by cells in the liver  Composition  B  Bile pigment (mostly from the breakdown of hemoglobin)  C  P  E

Role of the Liver in Metabolism Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Several roles in  Detoxifies  Degrades  Produce cholesterol, blood proteins ( and clotting proteins)  Plays a central role in

Gall Bladder Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sac found in hollow of liver  Stores bile from the liver by way of the  Bile is introduced into the in the presence of fatty food  Gallstones can cause blockages

Processes of the Digestive System Slide 14.42a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  – getting food into the mouth  – moving foods from one region of the digestive system to another

Processes of the Digestive System Slide 14.42b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Peristalsis – alternating waves of  Segmentation – moving materials back and forth to aid in Figure 14.12

Processes of the Digestive System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mechanical digestion  Mixing of food in the mouth by the  of food in the stomach  in the small intestine

Processes of the Digestive System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Chemical Digestion  break down food molecules into their building blocks  Each major food group uses different  Carbohydrates are broken to simple  Proteins are broken to amino  are broken to fatty acids and alcohols

Processes of the Digestive System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A  End products of digestion are absorbed in the blood or  Food must enter mucosal cells and then into blood or lymph capillaries  D  Elimination of indigestible substances as feces

Processes of the Digestive System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 14.11

Control of Digestive Activity Slide 14.47a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mostly controlled by reflexes via the division  Chemical and mechanical receptors are located in organ walls that trigger

Control of Digestive Activity Slide 14.47b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Stimuli include:  Stretch  of the contents  Presence of breakdown products  Reflexes include:  Activation or inhibition of secretions  Smooth

Nutrition - Take a Class! Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Nutrient – substance used by the body for growth, maintenance, and repair  Categories of nutrients  Carbohydrates: simple sugars, starches,  : triglycerides, phospholipids, fatty acids  P : amino acids  V  M  W

Body Energy Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Energy intake = total energy output (heat + work + energy storage)  Energy intake is liberated during food  Energy output  Heat is usually about  Storage energy is in the form of fat or