(VOCAB) Bone Tissue and The Skeletal System

Articular cartilage

Thin layer of cartilage covering an epiphysis; reduces friction and acts as a shock absorber.

Articulation

Where two bone surfaces meet.

Bone

Hard, dense connective tissue that forms the structural elements of the skeleton.

Canaliculi (Singular = canaliculus)

Channels within the bone matrix that house one of an osteocyte’s many cytoplasmic extensions that it uses to communicate and receive nutrients.

Cartilage

Semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement.

Central Canal

Longitudinal channel in the center of each osteon; contains blood vessels, nerves, and lymphatic vessels; also known as teh Haversian canal.

Closed Reduction

Manual manipulation of a broken bone to set it into its natural position without surgery.

Compact Bone

Dense osseous tissue that can withstand compressive forces.

Diaphysis

Tubular shaft that runs between the proximal and distal ends of a long bone.

Diploë

Layer of spongy bone, that is sandwiched between two the layers of compact bone found in flat bones.

Endochondral ossification

Process in which bone forms by replacing hyaline cartilage.

Endosteum

Delicate membranous lining of a bone’s medullary cavity.

Epiphyseal line

Completely ossified remnant of the epiphyseal plate.

Epiphyseal plate (also, growth plate)

Sheet of hyaline cartilage in the metaphysis of an immature bone; replaced by bone tissue as the organ grows in length.

Epiphysis

Wide section at each end of a long bone; filled with spongy bone and red marrow.

External callus

Collar of hyaline cartilage and bone that forms around the outside of a fracture.

Flat Bone

Thin and curved bone; serves as a point of attachment for muscles and protects internal organs.

Fracture

Broken bone

Fracture hematoma

Blood clot that forms at the site of a broke bone.

Hematopoiesis

Production of blood cells, which occurs in the red marrow of the bones.

Hole

Opening or depression in a bone

Hypercalcemia

Condition characterized by abnormally high levels of calcium.

Hypocalcemia

Condition characterized by abnormally low levels of calcium.

Internal Callus

fibrocartilaginous matrix, in the endosteal region, between the two ends of a broken bone.

Intramembranous Ossification

Process by which bone forms directly from mesenchymal tissue.

Irregular Bone

Bone of complex shape; protects internal organs from compressive forces.

Lacunae (singular = lacuna)

Spaces in a bone that house an osteocyte.

Long Bone

Cylinder-shaped bone that is longer than it is wide; functions as a lever.

Medullary Cavity

Hollow region of the diaphysis; filled with yellow marrow.

Modeling

Process, during bone growth, by which bone is resorbed on one surface of a bone and deposited on another.

Nutrient Foramen

Small opening in the middle of the external surface of the diaphysis, through which an artery enters the bone to provide nourishment.

Open Reduction

Surgical exposure of a bone to reset a fracture.

Orthopedist

Doctor who specializes in diagnosing and treating musculoskeletal disorders and injuries.

Osseous Tissue

Bone tissue; a hard, dense connective tissue that forms the structural elements of the skeleton.

Ossification (also, osteogenesis)

Bone formation

Ossification Center

Cluster of osteoblasts found in the early stages of intramembranous ossification.

Osteoblast

Cell responsible for forming new bone.

Osteoblast

Cell responsible for resorbing bone.

Osteocyte

Primary cell in mature bone; responsible for maintaining the matrix.

Osteogenic Cell

Undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts.

Osteoid

Uncalcified bone matrix secreted by osteoblasts.

Osteon (also, Haversian system)

Basic structural unit of compact bone; mad eof concentric layers of calcified matrix.

Osteoporosis

Disease characterized by a decrease in bone mass; occurs when the rate of bone resorption exceeds the rate of bone formation, a common occurrence as the body ages.

Perforating Canal (also, Volkmann’s Canal)

Channel that branches off from the central canal and hoses vessels and nerves that extend to the periosteum and endosteum.

Perichondrium

Membrane that covers cartilage.

Periosteum

Fibrous membrane covering the outer surface of bone and continuous with ligaments.

Primary ossification center

Region, Deep in the periosteal collar where bone development starts during endochondral ossification.

Projection

Bone markings where part of the surface sticks out above the rest of the surface, where tendons and ligaments attach.

Proliferative Zone

Region of the epiphyseal plate that makes new chondrocytes to replace those that die at the diaphyseal end of the plate and contributes to longitudinal growth of the epiphyseal plate.

Red marrow

Connective tissue in the interior cavity of a bone where hematopoiesis takes place.

Remodeling

Process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is resorbed.

Reserve Zone

Region of the epiphyseal plate that anchors the plate to the osseous tissue of the epiphysis.

Secondary ossification center

Region of bone development in the epiphyses.

Sesamoid bone

Small, round bone embedded in a tendon; protects the tendon from compressive forces.

Short Bone

Cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion.

Skeletal System

Organ system composed of bones and cartilage that provides for movement, support, and protection.

Spongy Bone (also, cancellous bone)

Trabeculated osseous tissue that supports shifts in weight distribution.

Trabeculae (singular = trabecula)

Spikes or sections of the lattice-like matrix in spongy bone.

Yellow Marrow

Connective tissue in the interior cavity of a bone where fat is stored.

Zone of calcified matrix

Region of the epiphyseal plate closest to the diaphyseal end; functions to connect the epiphyseal plate to the diaphysis

Zone of Maturation and Hypertrophy

Region of the epiphyseal plate where chondrocytes from the proliferative zone grow and mature and contribute to the longitudinal growth of the epiphyseal plate.