Bone Tissue

Vocabulary practice flashcards covering bone tissue histology, gross anatomy, intramembranous and endochondral ossification, bone remodeling, and structural/functional classifications of joints.

Osseous Tissue

The formal term for bone tissue, which is the primary connective tissue type found in bones consisting of a specialized extracellular matrix with scattered cells.

Inorganic Matrix

The mineral portion of bone extracellular matrix comprising approximately $65\%$ of bone weight, primarily made of calcium and phosphorus salts forming hydroxyapatite crystals that resist compression and confer hardness.

Organic Matrix (Osteoid)

The non-mineral portion of bone extracellular matrix comprising approximately $35\%$ of bone weight, composed of collagen fibers, proteoglycans, glycosaminoglycans, glycoproteins, and bone-specific proteins that provide tensile strength and flexibility.

Hydroxyapatite Crystals

Mineral crystals formed by calcium and phosphate salts that incorporate into bone extracellular matrix, giving bone its hardness and compressive strength.

Osteogenic Cells

Bone stem cells derived from mesenchyme that differentiate into osteoblasts in response to specific chemical signals.

Osteoblasts

Bone-forming cells that synthesize and secrete organic bone matrix components during bone deposition and assist in matrix mineralization.

Osteocytes

Mature bone cells derived from osteoblasts that have become entrapped within lacunae in the bone matrix, responsible for maintaining the matrix and regulating bone remodeling.

Osteoclasts

Large, multinucleated cells responsible for bone resorption by breaking down bone matrix and releasing minerals, sugars, and amino acids into the bloodstream.

Diploë

The internal spongy bone layer positioned between the two external layers of compact bone in flat bones.

Red Bone Marrow

A specialized connective tissue composed of a reticular fiber network supporting hematopoietic stem cells that generate red blood cells, white blood cells, and platelets.

Yellow Bone Marrow

Bone marrow primarily composed of blood vessels and adipocytes that stores triglycerides and can convert back into red bone marrow during severe blood loss.