| Lab 20 Small & Large Intestines: 1) Index 2) Things to Identify 3) Duodenum 4)Jejunum 5) Ileum 6) Appendix 7) Colon 8) Rectum 9) Rectal Anal Junction 10) Anus 11)Comparison of Structures 12)Practical |
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Rectal
Anal Junction
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| # 126 - Rectum, anus junction, monkey, l.s., h-e |
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Locate the junction between these two organs and oberve the transition between rectal epithelium (simple columnar epithelium with goblet cells) and anal epithelium (a thick, nonkeratinized, stratified squamous epithelium). Note the number of goblet cells on the surface and lining the glands in the rectal area. Note how the muscularis mucosae breaks up and is lost at the junction, as are the intestinal glands. Note also the enlarged blood vessels in this anal region. Some sections may show striated skeletal muscle of the anal sphincter. References: Gartner, p. 291, Fig. 4Ross, p. 494 - 495 Wheater, p. 268, Fig. 14.30 |
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This is a low power image of the Junction between the Rectum and the Anus. The blue arrow is outlining the end of the Rectum, where you can still make out the strait and parallel crypts of lieberkuhn, while the red arrow is pointing to the region where the Anus begins. The anus has a Stratified Squamous Non-Keratinized epithelium, which begins at the black arrow. Blue arrow - end of Rectum Red arrow - Beginning of Anus Black arrow - Transition point
Here is another look at the Rectal Anal Junction. The Red arrow is pointing to the last Crypt of Lieberkuhn before the anus begins. The blue arrow is pointing to the point at which the epithelium of the Anus begins and you lose the goblet cells.
Blue arrow - Anal Epithelium Red arrow - Rectal Crypt |
Rectal-Anal Junction
Transition between Rectum and Anus |
