Bone Anatomy, Histology, and Composition Vocabulary

Comprehensive vocabulary flashcards focusing on structural features, cell types, tissues, and chemical components of bone from the lecture notes.

Small leucine-rich proteoglycans (SLRPs)

Non-collagenous proteoglycans necessary for cell proliferation, mineral deposition, and remodeling in bone.

Glycoproteins

Proteins with covalently bound carbohydrates in various patterns that are necessary for mineral regulation.

Epiphysis

The end part of a long bone, which initially grows separately from the shaft.

Diaphysis

The shaft or central part of a long bone that contains mostly compact bone.

Metaphysis

The region of a long bone where the epiphysis joins the diaphysis.

Epiphyseal plate

A hyaline cartilage plate located in the metaphysis at each end of a long bone.

Medullary space

The hollow part of bone that contains bone marrow.

Trabecular bone

A hierarchical, spongy, porous material composed of hard and soft tissue components found at epiphyses, metaphyses, and vertebral bodies.

Compact bone

The hard, dense outer layer of all bones throughout the body.

Periosteum

A dense outer layer of bone containing vascular connective tissue that envelopes bones except at joint surfaces.

Endosteum

A single loose connective tissue layer lining the inner surface of the bony wall and bone marrow.

Osteoblasts

Mononuclear cells originating from mesenchymal cells in bone marrow that form new bone during ossification.

Primary ossification

The formation of a 1-cell thick layer covering bone surfaces undergoing remodeling.

Osteoclasts

Large, mobile, multinucleated cells located at the bone surface that actively resorb bone.

Osteocytes

Inactive and entrapped osteoblasts within the bone matrix that possess long cytoplasmic projections.

Osteoprogenitor

A germ cell that differentiates into other cell types in bone.

Ground substance

A substance within compact bone rich in a mineralized calcium phosphate compound known as hydroxyapatite.

Osteon

Cylindrical structures composed of concentric layers of bone tissue called lamellae surrounding a central canal.

Haversian canals

Minute tubes forming a network in bone that contain blood vessels running parallel to the length of the bone.

Volkmann canals

Channels containing smaller blood vessels running perpendicular to Haversian canals, connecting them to the periosteum and medullary cavity.

Lacunae

Small areas or holes in the bone matrix where osteocytes reside.

Canaliculi

Tunnels forming a labyrinth of connections between neighboring osteocytes through which cytoplasmic projections extend.

Trabeculae

Thin columns and plates of bone that form a spongy structure along stress lines.

Red bone marrow

Marrow containing hematopoietic tissue that forms blood cells, located in flat bones and proximal ends of the humerus and femur in adults.

Yellow bone marrow

Marrow containing mostly adipose tissue, located primarily in long bones.

Hydroxyapatite crystals

The general structure of bone mineral with the chemical formula $\text{Ca}_{10}(\text{PO}_4)_6(\text{OH})_2$.

Type I collagen

The main form of collagen found in bone ($90\%$), synthesized primarily in osteoblasts.

Tropocollagen

A rigid structure formed by three braided collagen fibrils, five of which join to form a microfibril.

Hydroxyproline

A neutral heterocyclic protein amino acid found in bone and gelatin, used as a diagnostic indicator of bone destruction when elevated in blood.

Hydroxylysine

An amino acid unique to collagen-like peptides containing a covalent norleucine cross-link across adjacent collagen fibrils to stabilize them.

Osteocalcin

A protein produced solely by osteoblasts that aligns apatite crystals parallel with collagen fibrils and acts as a chemoattractant for osteoclasts.