Chapter 6: Cartilage and Bone

Comprehensive vocabulary flashcards covering the characteristics, growth, anatomy, and physiology of cartilage and bone as described in Chapter 6.

Skeletal system

An organ system with tissues that grow and change throughout life, consisting of bones, cartilages, ligaments, and other supportive connective tissues.

Cartilage

A semirigid connective tissue that is weaker than bone but more flexible and resilient; mature forms are avascular.

Chondroblasts

Cells that produce the cartilage matrix.

Chondrocytes

Mature cartilage cells that are surrounded by matrix and occupy small spaces called lacunae.

Lacunae

Small spaces within the matrix of cartilage or bone that house chondrocytes or osteocytes.

Interstitial growth

Growth from within the cartilage; in bone, it refers to growth in length occurring at the epiphyseal plate.

Appositional growth

Growth along the periphery of cartilage or increase in a bone's diameter occurring in the periosteum.

Calcification

The deposition of minerals into the extracellular matrix of bone, making it sturdy and rigid.

Hemopoiesis

The process of blood cell production which occurs in red bone marrow.

Long bones

Bones that have a greater length than width, such as the femur and other upper and lower limb bones.

Short bones

Bones with nearly equal length and width, such as the carpals in the wrist and tarsals in the ankle.

Flat bones

Bones with thin, flat surfaces, such as the roof of the skull and the sternum.

Irregular bones

Bones with complex shapes, such as the vertebrae.

Diaphysis

The elongated, cylindrical shaft of a long bone.

Epiphysis

The knobby, enlarged region at each end of a long bone that strengthens joints and provides attachment sites for tendons and ligaments.

Metaphysis

The region in a long bone between the diaphysis and epiphysis which contains the epiphyseal plate.

Articular cartilage

A thin layer of hyaline cartilage covering the epiphysis that reduces friction and absorbs shock in moveable joints.

Medullary cavity

The hollow, cylindrical space within the diaphysis that contains yellow bone marrow in adults.

Endosteum

A layer covering most internal surfaces of bones containing osteoprogenitor cells, osteoblasts, and osteoclasts; active in bone remodeling and repair.

Periosteum

Dense irregular connective tissue covering external surfaces of bones (except where articular cartilage is present), attached by perforating fibers.

Osteoprogenitor cells

Mesenchymal stem cells located in the endosteum and periosteum that can produce more stem cells or osteoblasts.

Osteoblasts

Cells that form the bone matrix by secreting the organic component called osteoid.

Osteocytes

Bone cells residing in lacunae that maintain the matrix and detect mechanical stress on the bone.

Osteoclasts

Large, multinuclear cells with a ruffled border that dissolve bone matrix through bone resorption.

Osteolysis

The release of stored calcium and phosphate from bone into the blood.

Hydroxyapatite

The primary inorganic component of bone matrix composed of calcium phosphate and calcium hydroxide: $Ca_{10}(PO_4)_6(OH)_2$.

Compact bone

Bone tissue that is solid and relatively dense, forming the external surfaces of long and flat bones.

Spongy bone

Bone tissue consisting of an open lattice of narrow plates called trabeculae; also called diploe in flat bones of the skull.

Osteon

The basic functional and structural unit of adult compact bone; also known as a Haversian system.

Central canal

A cylindrical channel at the center of the osteon that carries blood vessels and nerves.

Concentric lamellae

Rings of bone matrix that surround the central canal of an osteon.

Canaliculi

Tiny interconnecting channels extending between lacunae that allow osteocytes to connect and communicate.

Perforating canals

Passageways carrying blood vessels and nerves that run perpendicular to central canals to help connect them.

Ossification

The process of formation and development of bone connective tissue; also known as osteogenesis.

Intramembranous ossification

A pattern of bone development from mesenchyme that produces the flat bones of the skull, some facial bones, the mandible, and the central clavicle.

Endochondral ossification

A pattern of bone development that begins with a hyaline cartilage model and produces most bones of the skeleton.

Epiphyseal plate

A layer of hyaline cartilage at the boundary of the epiphysis and diaphysis that is the site of interstitial growth.

Bone remodeling

The continual production of new bone and resorption of old bone, stimulated by stress and helping maintain mineral levels.

Calcitonin

A hormone that promotes calcium deposit from blood to bone and inhibits osteoclast activity.

Parathyroid hormone

A hormone that stimulates osteoclasts to resorb bone, thereby increasing calcium levels in the blood.

Vitamin D

A vitamin that stimulates calcium absorption from the GI tract into the blood for use in bone formation.

Compound fracture

A bone break where the broken bone penetrates the skin.

Condyle

A large, smooth, rounded oval structure serving as an articulating surface.

Foramen

A rounded passageway through a bone for the transmission of blood vessels and nerves.

Osteoporosis

A condition characterized by a decrease in bone mass, often resulting from osteopenia, which increases the risk of fractures.