PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham 22

HUMAN ANATOMY

fifth edition

PART 4

The Digestive System

MARIEB | MALLATT | WILHELM

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Pancreas  Exocrine function 

Acinar cells

make, store, and secrete pancreatic enzymes  Enzymes are activated in the duodenum  Endocrine function   Produces

insulin

and

glucagon

Regulates blood sugar Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Exocrine Pancreas: Histology Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 22.29a, b

Disorders of the Digestive System 

Intestinal obstruction

 Mechanical obstructions  Adhesions, tumors, or foreign objects  Nonmechanical obstruction  Halt in peristalsis   Trauma Intestines touched during surgery Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Disorders of the Digestive System 

Inflammatory bowel disease

 Inflammation of intestinal wall   Crohn’s disease Ulcerative colitis 

Viral hepatitis

  Jaundice and flu-like symptoms Major types – A, B, C, and G Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Disorders of the Digestive System  Cystic Fibrosis and the Pancreas  Pancreatic ducts become blocked with mucus  Clogged ducts prevent pancreatic juices from entering small intestine  Leads to malabsorption of fats and other nutrients Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Embryonic Development of the Digestive System  Alimentary canal formed in week three  Encloses tubular portion of yolk sac 

Vitelline duct

 Landmark dividing into three regions    Forgut Midgut Hindgut Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Embryonic Development of the Digestive System Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 22.30a, b

The Digestive System in Later Life   Middle age – gallstones and ulcers Old age – activity of digestive organs decline  Fewer digestive juices and enzymes produced    Absorption is less efficient Dehydration of fecal mass leads to constipation Diverticulosis and cancer of digestive organs Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings