Question

Haversian canal contains
A. Blood vessels and nerves
B. Blood vessels only
C. Lymphatic only
D. Connective tissue only

Answer 1

Haversian canal is the structural and functional unit of compact bone. In addition to the imperative medullary canal, it's miles located that the wall of the compact bones is pierced by several narrow longitudinal tunnels known as the Haversian canals that are branches of horizontal channels, acknowledged Volkmann’s canals.

Complete answer:
The char­acteristic feature of the mammalian bones are Haversian canals which are located in the matrix. Every Haversian canal contains a vein, artery, a lymph vessel, some bone cells and nerve, all packed in with connective tissue.
Now let’s study each option one by one
Blood vessels and nerves- Haversian canals contain blood vessels, lymphatic vessels and nerves. Around every Haversian canal, varying numbers of layers of bone are deposited in concentric circles (Haversian lamellae). Lacunae (tiny spaces) are present between adjacent layers; these lacunae are also organized in circles across the Haversian canal. A quantity of pleasant wavy channels run out from all around the lacuna and are called the canaliculi. The lacunae contain the osteocytes which end up imprisoned by the surrounding calcium deposit and the canaliculi con­tain the processes of the osteocytes. So, this option is correct.
Blood vessels only- Haversian canals contain blood vessels but also contain nerves and lymphatic vessels, so this option is not correct.
Lymphatic only- lymphatic vessel is present in Haversian canal but other components are also present.so, this option is not correct.
Connective tissue only- Haversian canal contains a vein, artery, a lymph vessel, some bone cells and nerve, all packed in with connective tissue, saying Haversian canal contains only connective tissue is not correct.

Hence the correct option is (A).

Note:
Through the canaliculi, the lacunae commu­nicate with each other as well as with the crucial Haversian canal, however, most commonly do not communicate with the lacunae of the opposite aversion systems. Each Haversian canal collectively with a concentric lamellated bony deposit, the lacunae and the canaliculi, composes one Haversian gadget. Forming the outer boundary of such a system and separating this system from neighbouring ones, a brilliant skinny line is regularly noticed. This is known as the cementing line of Ebner.