Question

Volkmann’s canals are found in
A. Bones of birds
B. Bones of amphibians
C. Bones of mammals
D. Cartilage of mammals

Answer 1

Hint: Bone is the hardest tissue of the body, which provides a structural frame to the body. Bone consists of four parts: periosteum, matrix, endosteum and bone marrow. Haversian canals present in bone are connected by Volkmann’s canal, with each other and to the periosteum.

Complete answer:
Bones are made up of hard and non-pliable ground substances that are rich in calcium salts and collagen fibres and give bone its strength. Bones consist of four parts.
a) Periosteum: It is a thick and tough sheath that forms an envelope around the bone. It is composed of collagen fibrous tissue. The periosteum contains blood vessels and osteoblasts which produce new bone material.
b) Matrix: The matrix is tough and contains both inorganic (65%) and organic (35%) substances. The inorganic salts present in the matrix are calcium phosphates, calcium carbonate, calcium fluoride, magnesium phosphate. These salts are responsible for the very hard matrix of bones. The osteocytes are found in lacunae. Haversian canals have arteries and veins.
Volkmann’s canal is small minute channels in the bone. They interconnect the Haversian canals with each other and the periosteum of the bone. Presence of Volkmann's canal is a characteristic feature of mammalian bone.

So, the correct answer is option C.

Note:
i) Endosteum: It is present outer to the marrow cavity and consists of bone cells. The long bones grow in thickness from two sides (bidirectional growth).
ii) Bone Marrow: In long bones ( limb bones ), a cavity called the bone marrow cavity is present inner to the endosteum. It contains myelogenous or myeloid tissue.