Identify:

Macroscopic

• The longitudinally sectioned colon

• The luminal surface

• A thin dark pink coloured line, the mucosa.
• A central light pink coloured area with fine pink coloured structures, the submucosa.
• An outer pink coloured irregular area, the outer muscle layer.

• Serosa

Microscopic

• Single cell gland or goblet cell (pale staining)

• Simple tubular gland. Note that the simple tubular gland is the whole test tube shaped structure and that it is lined with goblet cells and columnar epithelial cells.

• In the lamina propria of the mucosa, which comprises an epithelial layer and a loose connective tissue layer, the lamina propria, the following cells must be identified:

• Fibroblasts
• Plasma cells
• Macrophages
• Mast cells
• Eosinophils
• Lymphocytes
• Smooth muscle fibers

Draw and annotate:

A line diagram of the colon.

A goblet cell as well as a simple tubular gland (with goblet cells and columnar epithelial cells), as seen in longitudinal section.

The different cell types. List with each cell type, their distinguishing characteristics.

1. What are the characteristics of a goblet cell?
2. What cells form a simple tubular gland?
3. What are the distinguishing characteristics of the crypts as far as their structure and arrangement are concerned?
4. What is typical of the outer layer of M. externa?
5. What are the similarities and differences between the colon, appendix, vermiformis, ileum and duodenum?

Microscope

Medium magnification

High magnification

High magnification of the colon
High magnification of the colon

Very high magnification

• Fig 42-001
• Fig 42-002
• Fig 42-003
• Fig 42-004
• Colon
• Parasympathetic ganglion