Transcript Document

PowerPoint® Lecture Slides
prepared by Leslie Hendon,
University of Alabama,
Birmingham
22
HUMAN
ANATOMY
PART 4
The Digestive
System
fifth edition
MARIEB | MALLATT | WILHELM
Copyright © 2008 Pearson Education, Inc.,
publishing as Benjamin Cummings
The Liver

Largest gland in the body
 Performs over 500 functions
 Digestive function
 Bile production
 Performs many metabolic functions
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Visceral Surface of the Liver
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.26
Microscopic Anatomy of the Liver


Hepatocyte – functional cells of the liver
Portal triad composed of
 Bile duct tributary
 Branch of hepatic portal vein
 Branch of hepatic artery

Kupffer cells – destroy bacteria
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Microscopic Anatomy of the Liver

Some functions of hepatocytes
 Rough ER manufactures blood proteins
 Smooth ER produces bile salts, detoxifies poisons
 Peroxisomes detoxify poisons (alcohol)
 Golgi apparatus packages secretory products
 Mitochondria provide energy for liver processes
 Glycosomes store sugar
 Great capacity for regeneration
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Microscopic Anatomy of Liver
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.27a, c, d
The Gallbladder


Stores and concentrates bile
Expels bile into duodenum
 Bile emulsifies fats

Cholecystokinin – released from enteroendocrine
cells in response to fatty chyme
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
The Gallbladder
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.20
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