In histology

Histology

Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...

, a lacuna is a small space containing an osteocyte

Osteocyte

An osteocyte, a star-shaped cell, is the most abundant cell found in compact bone. Cells contain a nucleus and a thin ring of cytoplasm. When osteoblasts become trapped in the matrix they secrete, they become osteocytes...

 in bone or chondrocyte

Chondrocyte

Chondrocytes are the only cells found in cartilage. They produce and maintain the cartilaginous matrix, which consists mainly of collagen and proteoglycans...

 in cartilage.

Bone

The Lacuna are situated between the lamella, and consist of a number of oblong spaces. In an ordinary microscopic section, viewed by transmitted light, they appear as fusiform opaque spots. Each lacuna is occupied during life by a branched cell, termed an osteocyte

Osteocyte

An osteocyte, a star-shaped cell, is the most abundant cell found in compact bone. Cells contain a nucleus and a thin ring of cytoplasm. When osteoblasts become trapped in the matrix they secrete, they become osteocytes...

, bone-cell or bone-corpuscle. Lacunae are connected to one another by small canals called canaliculi

Canaliculus (bone)

Canaliculi are microscopic canals between the various lacunae of ossified bone. The radiating processes of the osteocytes project into these canals. These cytoplasmic processes are joined together by gap junctions. Osteocytes do not entirely fill up the canaliculi. The remaining space is known...

.
A lacuna never contains more than one osteocyte.

Cartilage

The cartilage cells or chondrocytes are contained in cavities in the matrix, called cartilage lacuna; around these the matrix is arranged in concentric lines, as if it had been formed in successive portions around the cartilage cells. This constitutes the so-called capsule of the space. Each lacuna is generally occupied by a single cell, but during the division of the cells it may contain two, four, or eight cells. Lacunae are found between narrow sheets of calcified matrix that are known as lamellae (lah-MEL-le).

External links

• Photo at ohio-state.edu