Microscopic Structure of Compact Bone 11. Several descriptions of bone structure are given below. Identify the structure involved by choosing the appropriate term from the key and placing its letter in the blank. Then, on the photomicrograph of bone on the right (175x), identify all structures named in the key and draw a bracket enclosing a single osteon. Key: a canaliculi b. central canal C. lacuna d. lamella 1. layer of bony matrix around a central canal 2. site of osteocytes 3. longitudinal canal carrying blood vessels, lymphatics, and nerves 4. tiny canals connecting osteocytes of an osteon
The Correct Answer and Explanation is :
To answer the question about the microscopic structure of compact bone, we need to identify the structures involved by matching the descriptions to the terms given in the key. Here’s how each description corresponds to the key:
- Layer of bony matrix around a central canal – This corresponds to d. lamella. Lamellae are concentric rings of bone matrix that surround the central canal. They form the structural basis of the osteon.
- Site of osteocytes – This corresponds to c. lacuna. Lacunae are small spaces within the bone matrix where osteocytes (bone cells) reside. The osteocytes are embedded in the lacunae and communicate with each other through canaliculi.
- Longitudinal canal carrying blood vessels, lymphatics, and nerves – This corresponds to b. central canal. The central canal (also known as the Haversian canal) runs longitudinally through the osteon and contains blood vessels, nerves, and lymphatic vessels.
- Tiny canals connecting osteocytes of an osteon – This corresponds to a. canaliculi. Canaliculi are small, hair-like channels that radiate from the lacunae and connect osteocytes, allowing for the transfer of nutrients, waste, and signals between the cells.
Explanation:
Compact bone is made up of structural units called osteons (Haversian systems). Each osteon consists of concentric layers of bony matrix (lamellae) surrounding a central canal. Osteocytes, the cells that maintain bone tissue, reside in small spaces within the lamellae called lacunae. Canaliculi are tiny channels that extend from each lacuna, allowing osteocytes to communicate and exchange materials. The central canal, located at the center of each osteon, houses blood vessels, nerves, and lymphatic vessels, supplying nutrients and oxygen to the bone tissue.
This structure is essential for maintaining bone strength and integrity while allowing the bone to respond to mechanical stress.
I’ll generate a photomicrograph for the bone with labeled structures.
The photomicrograph of compact bone at 175x magnification has been generated. It clearly shows the osteons, lamellae, lacunae, canaliculi, and central canal, with the structures labeled. This should provide a helpful visual reference for understanding the microscopic anatomy of compact bone.
Let me know if you need further clarification or additional details!
