Lacuna (histology)

Lacuna (histology)

A Lacuna is a small space, cavity, or depression, especially in a bone, cartilage, or other tissue. In histology, the term is used to describe the spaces within a tissue that are occupied by cells. Lacunae are an integral part of the extracellular matrix and are found in various types of tissues, including bone tissue, cartilage, and fibrous connective tissue.

Structure and Function

Lacunae are typically small, oval-shaped spaces that are surrounded by a thin layer of extracellular matrix. They are most commonly found in bone tissue and cartilage, where they serve as the residence for osteocytes and chondrocytes, respectively.

In bone tissue, lacunae are interconnected by tiny channels called canaliculi, which allow for the exchange of nutrients and waste products between the osteocytes and the blood supply. This network of lacunae and canaliculi is essential for the health and maintenance of bone tissue.

In cartilage, lacunae house the chondrocytes, which are responsible for the production and maintenance of the cartilaginous matrix. Unlike in bone, the lacunae in cartilage are not interconnected, and the chondrocytes receive their nutrients through diffusion.

Clinical Significance

Changes in the size, shape, or number of lacunae can be indicative of various pathological conditions. For example, in osteoporosis, the lacunae in bone tissue may become larger and more numerous, reflecting the increased activity of osteoclasts and the loss of bone mass. Similarly, in osteoarthritis, the lacunae in cartilage may become depleted of chondrocytes, leading to the degradation of the cartilaginous matrix and the progression of the disease.

See Also

• Osteocyte
• Chondrocyte
• Extracellular matrix
• Canaliculi
• Osteoporosis
• Osteoarthritis