Lamella (surface anatomy)

Lamella (Surface Anatomy)

Micrograph of lamellae in bone tissue.

In surface anatomy, a lamella refers to a thin layer, membrane, or plate of tissue. The term is often used in the context of bone and cartilage structures, where lamellae are critical components of the osteon or Haversian system.

Structure

Lamellae are concentric rings of calcified matrix found in compact bone. They are organized around a central Haversian canal, which contains the bone's blood supply. Each lamella is composed of collagen fibers that run in parallel within a single lamella but in different directions in adjacent lamellae, providing strength and resilience to the bone.

Function

The primary function of lamellae is to provide structural support and strength to bones. The arrangement of collagen fibers in alternating directions helps bones resist torsion and bending forces. This structural organization is crucial for maintaining the integrity of the skeletal system.

Types of Lamellae

There are several types of lamellae found in bone tissue:

• Concentric lamellae: These are the rings of bone matrix that surround the Haversian canal in an osteon.
• Interstitial lamellae: These are remnants of old osteons that have been partially resorbed during bone remodeling.
• Circumferential lamellae: These are layers of bone matrix that extend around the entire circumference of the bone, just beneath the periosteum and endosteum.

Related Structures

• Osteocyte: A bone cell that resides in small cavities called lacunae, which are located between lamellae.
• Canaliculi: Tiny channels that connect lacunae and allow for communication and nutrient exchange between osteocytes.
• Volkmann's canals: Channels that run perpendicular to the Haversian canals, connecting them to the periosteum and the bone's blood supply.

Related Pages

• Bone
• Cartilage
• Osteon
• Haversian system
• Collagen