| Lab 3 Connective Tissue Proper :1)Index 2) Introduction to Connective Tissue / 3)Mucous CT / 4)Loose CT / 5)Reticular CT / 6)Adipose / 7)Dense Irregular CT / 8)Dense Regular CT / 9)Dense Regular Elastic CT / 10) Comparing Connective tissues / 11)Practical |
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DENSE
REGULAR ELASTIC CONNECTIVE TISSUE
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1. Elastic ligaments # 22 - Fibrous tissue, yellow elastic connective tissue, H&E |
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This slide contains cross and longitudinal sections through the ligamentum nuchae (ligament of the neck) which connects the lamina of one vertebrae to the lamina of the next, allowing flexibility as well as secure attachment. Ligaments are straps of Dense Regular Connective Tissue Proper which connect bone to bone. In elastic ligaments the parallel fibers that are under strain are elastic fibers which are woven together by collagen fibers. Note the avascularity and acellularity of this tissue. Why do you not see the elastic fibers in this H&E section? REFERENCE: Gartner, p. 50 - 51, Fig. 3 - 4 |
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This slide shows more of the collagen bundles that are characteristic of dense regular tissue. The yellow lines are outlining the collagen bundles. Can you guess what the blue arrows are pointing to? They are pointing to the fibroblasts making the collagen. It is important to remember that just because you dont see the elastic fibers, it does not mean they are not there!!! You just can't see them with this staining technique. Yellow line - Collagen bundle Blue Arrows - Fibroblast Nuclei |
Ligamentum nuchae |
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2. Elastic membranes in blood vessel walls #78 - Aorta, Verhoeff |
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#78 - Aorta, Verhoeff This slide has been stained by the Verhoeff technique to show elastic fibers in the wall of the aorta. With this stain, however, the smooth muscle cells between the elastic fibers are not clearly visible. Smooth muscle cells, not fibroblasts, are responsible for the synthesis of elastic fibers in the media of blood vessels. Reference: Gartner, p. 58 - 59, Fig. 3 p. 157, Fig. 1 - 4 Ross, p. 124 - 125, Fig. 3 p. 148, Fig. 1 - 4 p. 322 - 323, Fig. 1 - 6 Wheater, p. 144, Fig. 8.7 a,b DiFiore, p. 115, Fig. 8.3 |
| # 74 - Artery and vein, monkey, c.s., h-e |
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This section has not been stained to make elastic fibers prominent. With H&E, elastic fibers are refractile and appear glassy or transparent. Locate elastic fibers in the connective tissue under the endothelium where they form the wavy pink line that is the internal elastic lamina. Reference: Gartner, p.158 -159, Fig. , 1, 2, 3, 4 Ross. pp. 324 - 325 Wheater, p. 68, Fig. 4.9c p. 144, Fig. 8.7 - 8.8 |
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The green arrows are pointing to Red Blood Cells, so where are we? (referring to earlier hint) The yellow lines are outlining the prominent elastic fibers . Notice the dark red, wavy line appearance of them. They are very wavy to allow for stretching when the blood vessels lumen gets full. The blue arrows are pointing to Smooth Muscle Cell Nuclei. Now are there any fibroblasts found here in the wall of the artery? NO! This is a common mistake and a great exam question. Smooth muscle cells are responsible for making the elastic fibers here. Yellow line - elastic fibers Blue line - Smooth muscle cell nuclei Green Arrow - Red Blood Cells |
Artery |
