Bone: Histology, Constituents And Types

Bone: Histology, Constituents And Types

Question 1. Enumerate the various types of cells in the bone tissue.
Answer.

There are four types of cells in the bone tissue:

• Osteogenic cells: They are precursors of other cell types in the bone.
• Osteoblasts: They lay down the matrix of bone tissue.
• Osteocytes: They maintain bone matrix and are the main cells of bone tissue.
• Osteoclasts: They are involved in bone resorption.

Question 2. Define compact bone and list its histological features.
Answer.

The compact bone is dense and hard like ivory, with no visible spaces on naked-eye examination.

Bone Histological features

• Bone consists of Haversian systems. Each Haversian system (osteon) consists of a Haversian canal surrounded by 6–12 concentric bony lamellae.
• Haversian canals are connected and communicate with the marrow cavity through the bony canals called Volkmann’s canals.
• Bone has three types of bony lamellae:
  • Concentric lamellae, around the haversian canals.
  • Interstitial lamellae, between the haversian systems.
  • Circumferential lamellae, subjacent to the periosteum and adjacent to the endosteum.
• The bone is covered by the periosteum.

Sites

• Shaft of long bones.
• The outer layer of all bones.