Question

Where does the haversian canal present?
A. Spinal cord
B. Brain
C. Long bone
D. Sponge

Answer 1

Hint: A haversian canal is a structure of microtubules through which blood vessels and nerves pass through. One haversian canal allows for one nerve and two small capillaries. It is found in the bodies of vertebrates and allows for circulation and nerve impulse conduction. Many haversian canals form a haversian canal network.

Complete answer:
Option: A - Spinal cord does not possess any structure like haversian canals.
So, this option is not correct.
Option: B - Brain also does not possess any structure like haversian canals.
So, this is not the correct option.
Option: C - In long bones haversian canals are present as tubes and allow for nervous and vascular supply to bones.
So, this is the correct option.
Option: D - Canal system in sponges is associated with respiration while haversian canals are related to bones.
So, this is also not the correct option.

Hence, Option (C) is the correct answer.

Note:
Nerve fibres and a few capillaries are housed in Haversian canals, which are small tubes or tunnels in cortical bone. This permits bone to get oxygen and nutrients without becoming vascularized. These canals also communicate with bone cells via canaliculi, which are specific connections. Lamellae, or concentric layers of bone, generate Haversian canals, which are housed inside osteons. Osteons are cylinder-like structures that transfer oxygenated blood to bone and are placed parallel to the bone's surface along its long axis. Haversian canals that are intact make up around $$45\mathrm{\%}$$ of cortical bone, or little less than half.