Bones and Skeletal Tissues – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key terms related to cartilage, bone structure, growth, ossification, remodeling, and fracture repair from Chapter 6 lecture notes at Pasadena City College.

Cartilage

Flexible connective tissue located in the external ear, nose, articular and costal cartilages, larynx, trachea, intervertebral discs, pubic symphysis, and articular discs.

Chondrocyte

Mature cartilage cell that lives in a lacuna and maintains the cartilage matrix.

Lacuna

A small cavity in cartilage or bone matrix that houses a chondrocyte or osteocyte.

Perichondrium

Dense connective tissue membrane surrounding cartilage; resists outward pressure and contains chondroblasts for growth and repair.

Chondroblast

Immature cartilage cell in the perichondrium that secretes new cartilage matrix.

Appositional growth

Cartilage growth from the outside as chondroblasts in the perichondrium add new matrix to the surface.

Interstitial growth

Cartilage growth from within as chondrocytes divide and secrete new matrix.

Osteoid

Organic part of bone matrix (collagen and ground substance) providing flexibility and tensile strength.

Organic components (bone)

Cells, collagen fibers, and ground substance making up 35 % of bone matrix; allow resistance to stretching and twisting.

Inorganic components (bone)

Mineral salts (65 %), chiefly hydroxyapatite, giving bone hardness and compressional strength.

Hydroxyapatite

Crystallized calcium phosphate mineral that provides bone’s exceptional hardness.

Osteoprogenitor cell

Bone stem cell that differentiates into an osteoblast.

Osteoblast

Bone-forming cell that actively secretes bone matrix.

Osteocyte

Mature bone cell residing in a lacuna that keeps bone matrix healthy.

Osteoclast

Large, multinucleated cell derived from white blood cells that resorbs bone by secreting acids and enzymes.

Bone connective tissue

Dominant tissue of skeletal organs characterized by a mineralized matrix.

Long bone

Bone longer than wide with a shaft (diaphysis) and two ends; e.g., humerus, femur.

Short bone

Roughly cube-shaped bone such as carpals and tarsals.

Sesamoid bone

Type of short bone embedded in a tendon or muscle, e.g., the patella.

Flat bone

Thin, flattened, usually curved bone like the sternum or cranial bones.

Irregular bone

Bone with complex shape not fitting other categories; e.g., vertebrae, hip bones.

Compact bone

Dense outer layer of bone that appears smooth and solid.

Spongy bone

Internal lattice of bone made of trabeculae with open spaces containing red marrow.

Trabecula

Needle-like plate of bone forming the framework of spongy bone.

Diaphysis

Shaft of a long bone containing the nutrient foramen and medullary cavity.

Epiphysis

End of a long bone covered with a thin layer of articular (hyaline) cartilage.

Medullary cavity

Hollow space within the diaphysis filled with yellow marrow for fat storage.

Periosteum

Double-layered connective tissue membrane covering the outer surface of bone except at joints.

Sharpey’s fibers

Perforating collagen fiber bundles that anchor the periosteum to underlying compact bone.

Endosteum

Thin connective tissue membrane lining internal bone surfaces and canals.

Diploë

Internal spongy bone layer of flat bones sandwiched between two layers of compact bone.

Bone marking

Surface feature of bone indicating relations to muscles, ligaments, joints, or passages for vessels and nerves.

Osteon (Haversian system)

Cylindrical structural unit of compact bone composed of concentric lamellae surrounding a central canal.

Lamellae

Concentric rings of bone matrix within an osteon.

Central canal

Core of an osteon containing a nerve, artery, and vein.

Perforating canal

Canal running perpendicular to central canals, connecting blood and nerve supply of osteons.

Intramembranous ossification

Bone formation directly from mesenchyme producing cranial bones and clavicles.

Endochondral ossification

Bone formation that replaces a hyaline cartilage model; produces most bones of the body.

Primary ossification center

First site in the diaphysis of a cartilage model where bone tissue begins to replace cartilage.

Secondary ossification center

Ossification site that appears in the epiphyses of a long bone around birth.

Bone collar

Ring of compact bone that forms around the diaphysis of a cartilage model early in endochondral ossification.

Epiphyseal plate

Hyaline cartilage plate between epiphysis and diaphysis where lengthwise bone growth occurs during childhood.

Growth hormone

Pituitary hormone that stimulates growth of the epiphyseal plates.

Thyroid hormone

Hormone ensuring the skeleton retains proper proportions during growth.

Sex hormones

Estrogen and androgens that trigger adolescent growth spurts and later cause epiphyseal plate closure.

Bone remodeling

Continuous process in which bone is deposited and removed to maintain mineral balance and respond to mechanical stress.

Bone resorption

Removal of bone matrix by osteoclasts during remodeling.

Bone deposition

Addition of new bone matrix by osteoblasts during remodeling.

Simple fracture

Bone breaks cleanly but does not penetrate the skin.

Compound fracture

Broken bone ends protrude through the skin.

Closed reduction

Non-surgical realignment of fractured bone ends by manual manipulation.

Open reduction

Surgical realignment of fractured bone ends using pins or wires.