Graduate Microanatomy, 1998
Graduate Microanatomy, 1998
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Lab Exercises: Bone Development: Endochondral Bone Development: Intramembranous
Date page was last edited 06/06/04 |
Laboratory Exercises: Bone
Ground Bone
You can also see interstitial lamellae which are remnants of earlier remodeled Haversian systems. They are inbetween the osteons. Also, you can see the Volkmann's canals which run perpendicular to the Haversian canals and connect them. They also contain nerves and blood vessels. These photographs were taken from your slide 22 and they show examples of each of the features described. After you find the structures on your slide, for your own benefit, label as many of the structures written in bold as you can find on the photographs. We will check them out to make certain you have labeled them correctly
Ground Bone
Look at slide 21. This slide demonstrates a section through a rib. You can see layers of compact bone on the outside enclosing the marrow space in which a few bone trabeculae can be seen. Find the periosteum which is the flattened connective tissue outside the bone. You can also see osteocytes in their lacunae. The following photo shows the periphery of this section.
Compact Bone: Decalcified rib These sections of compact bone show the osteocytes in the lacunae and the concentric lamellae around the Haversian systems. The canaliculi are difficult to see. You may find them in your slide by focusing up and down. Note the blood vessel in the Haversian systems in the higher magnification photograph. Compact bone
Spongy Bone In your rib slide, you will see areas of spongy bone. Note that this is also organized in lamellae, although they are not concentrically arranged around a blood vessel. The spaces inside the spongy bone are the marrow spaces for red or yellow bone marrow.
Exercises 1. Compare and contrast the routes taken by blood vessels to osteocytes and chondrocytes.
2. Where would you look for osteoblasts in the above photo (of spongy bone)?
3. The grandmother of one of our graduate students had a broken arm which healed crooked. He decided to give her a series of exercises that were designed to strengthen the arm. As she exercised, the arm began to straighten. How did the exercises promote this healing?
4. Which bone cells are target cells for parathyroid hormone? Which are target cells for calcitonin?
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Look
at slide 22. This preparation demonstrates compact bone with its Haversian systems
and interstitial lamellae in cross section. A Haversian system (osteon)
contains concentric lamellae of bone arranged around a Haversian canal. The
Haversian canal contains blood vessels and nerves. In the lamellae, you can see many
lacunae which in living bone contain osteocytes. These cells interconnect with each
other and the blood supply via osteocyte processes. The osteocyte processes run in
canaliculi. Together, the lacunae and canaliculi look like tiny spiders distributed
in the lamellae. 
