John R. Hoffman is a Professor of Biology, public speaker and a scientist examining the recovery of the nervous system after injury. Since 2006 he has written several unpublished manuscripts and he is currently working on the first Nathaniel Smythe novel and short story collection. He spends his spare time with his family and running.

13. Digestive System

Specific Objectives:

At the end of this lecture, the student will be able to:

  1. Name the 3 types of paired salivary glands and compare them in terms of their contribution to salivary volume, proportion of serous and mucous cells, composition of their secretions.
  2. Describe the 2 types of cells of the exocrine pancreas in terms of staining characteristic, number, and secretory products.
  3. Sketch a schematic diagram of a section through 3 adjacent classic liver lobules and include and label the following: portal triads, hepatic artery, hepatic portal vein, bile duct, central vein, hepatic sinusoid, space of Disse, Hepatocytes, Kupffer’s cells, portal lobule (outline), hepatic acinus (outline), and direction of blood flow, bile flow, and lymph flow.
  4. Name and describe the 3 principal components of a portal triad.
  5. Name the 2 vessels that provide the liver’s blood supply and compare the blood they carry in terms of their origin, contribution to liver blood volume, oxygen content, and nutrient content.
  6. List the functions of the gallbladder.
  7. Sketch a cross section of a generalized tubular organ of the digestive tract showing the layered structure of its walls and indicate the location of the following: lumen,mucosa, submucosa, muscularis externa, serosa, epithelium, lamina propria, muscularis mucosa, Meissner’s plexus, Auerbach’s plexus, mesothelium
  8. List the organs of the digestive tract in the order in which food traverses them. Describe what happens to the food in each.
  9. Compare the gastric glands found in the mucosa of the 3 regions of the stomach in terms of the types of cells present, secretory products, staining properties, depth of gastric pits.
  10. List the 3 features of the wall of the small intestine that increase the surface area exposed to the lumen and thus promote absorption of nutrients.
  11. Name the 5 important cell types found in the epithelium lining the intestinal lumen and the crypts of Lieberkuhn and compare them in terms of their primary function (and secretory product, if any), distribution, distinguishing structural characteristics, and special staining properties (if any).
  12. Compare the duodenum and ileum in terms of the shape and number of villi, presence of submucosal glands, presence of lymphoid tissue, and number of goblet cells.
  13. List the functions of the large intestine.
  14. Indicate how the large intestine differs from the small intestine in terms of the plicae circulares and villi, number of goblet cells, amount of lymphoid tissue, and outer layer of the muscularis externa.

Lectures

Part 1

This lecture reviews the basic functions of the digestive system and the wall structure of digestive tract organs.

Part 2

This lecture reviews the basic structure and function of the oral cavity and the esophagus

Part 3

This lecture reviews the basic structure and function of the stomach.

Part 4

This lecture reviews the basic structure and function of the small and large intestines.

Part 5

This lecture reviews the basic structure and function of the digestive system glands, including the salivary glands and the pancreas.

Part 6

This lecture reviews the basic structure and function of the liver.

Laboratory

Digestive System Prelab Part 1

This video provides an overview of the important concepts to remember as studying histological images to learn about the digestive tract of the digestive system, including the esophagus, stomach, small and large intestine.

Digestive System Prelab Part 2

This video provides an overview of the important concepts to remember as studying histological images to learn about the glands of the digestive system, including the salivary glands, pancreas, and liver.

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