Bone and Skeletal Tissues Vocabulary

Comprehensive vocabulary flashcards covering skeletal tissues, cartilage classification, bone markings, cells, histology, ossification, growth, fractures, and bone pathologies.

Hyaline Cartilage

The most abundant type of cartilage, containing large amounts of water and matrix with only collagen fibers; functions to resist compression.

Elastic Cartilage

A type of cartilage whose matrix contains elastic and collagen fibers, functioning to tolerate repeated bending in structures such as the epiglottis, ear, and auditory tube.

Fibrocartilage

Cartilage consisting of dense irregular connective tissue with thick collagen fibers surrounding chondrocytes, functioning to resist compression and pulling forces.

Chondrocyte

The mature cell type found within lacunae in cartilage tissues.

Lacuna

A small cavity or space within the matrix of cartilage or bone that houses cells such as chondrocytes or osteocytes.

Long Bone

A bone category characterized by a shaft and ends, exemplified by the humerus and femur.

Short Bone

A cube-shaped bone category exemplified by the talus, carpals, and tarsals.

Sesamoid Bone

A specialized type of short bone that forms within tendons, such as the patella.

Flat Bone

A thin, flattened bone category exemplified by the sternum and scapula.

Irregular Bone

A bone with a complex shape that does not fit into other classification categories, such as a vertebra.

Sutural Bone

Small, irregularly shaped bones located within the suture joints of the skull.

Tuberosity

A large rounded projection on a bone that may be roughened, serving as a site for muscle and ligament attachment.

Crest

A narrow, prominent ridge of bone that serves as an attachment site for muscles and ligaments.

Trochanter

A very large, blunt, irregularly shaped process, the only examples of which are located on the femur.

Line (Bone Marking)

A narrow ridge of bone that is less prominent than a crest.

Tubercle

A small rounded projection or process on a bone.

Epicondyle

A raised area situated on or above a condyle.

Spine (Bone Marking)

A sharp, slender, often pointed projection on a bone.

Process (Bone Marking)

Any bony prominence.

Head (Bone Marking)

A bony expansion carried on a narrow neck that forms a joint.

Facet

A smooth, nearly flat articular surface on a bone.

Condyle

A rounded articular projection that often articulates with a corresponding fossa.

Foramen

A round or oval opening through a bone for the passage of vessels and nerves.

Groove (Bone Marking)

A furrow along a bone surface for the passage of blood vessels and nerves.

Fissure

A narrow, slitlike opening through a bone.

Notch

An indentation at the edge of a bone structure.

Fossa

A shallow basinlike depression in a bone, often serving as an articular surface.

Meatus

A canal-like passageway through a bone.

Sinus

An air-filled cavity within a bone, lined with mucous membrane.

Diaphysis

The tubular shaft forming the main long axis of a long bone.

Epiphysis

The expanded end portion of a long bone, containing internal spongy bone.

Periosteum

An external connective tissue membrane covering bone, consisting of an outer dense irregular connective tissue layer and an inner osteogenic layer containing osteoblasts and osteoclasts.

Endosteum

An internal connective tissue membrane lining bony canals, the medullary cavity, and covering trabeculae.

Diploë

The internal layer of spongy bone tissue found in flat bones, sandwiched between outer layers of compact bone.

Organic Bone Matrix

The organic component of bone matrix (primarily osteoid composed of collagen) secreted by osteoblasts, contributing flexibility and tensile strength to resist bending and twisting, accounting for approximately $35\%$ of bone weight.

Hydroxyapatites

The inorganic mineral composition of bone tissue (predominantly calcium phosphate) that provides bone hardness and resistance to compression forces.

Osteogenic Cell

A stem cell in bone tissue that differentiates into osteoblasts.

Osteoblast

A bone-forming cell that secretes osteoid and forms the matrix of bone tissue.

Osteocyte

A mature bone cell residing in a lacuna that maintains and monitors bone tissue matrix.

Osteoclast

A specialized cell responsible for bone resorption.

Osteon (Haversian System)

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

Lamellae

Concentric matrix rings or layers of bone tissue surrounding the central canal of an osteon.

Central Canal (Haversian Canal)

A longitudinal channel running through the core of an osteon that houses blood vessels and nerve fibers.

Perforating Canal (Volkmann's Canal)

Canals running at right angles to central canals that connect blood vessels and nerves from the periosteum to central canals and the medullary cavity.

Canaliculi

Hairlike canals that connect lacunae to each other and to the central canal, allowing nutrients to pass between osteocytes.

Intramembranous Ossification

The process of bone development directly from fibrous connective tissue membranes, forming flat skull bones and the clavicle.

Endochondral Ossification

The process of bone formation wherein a pre-existing hyaline cartilage model is calcified and replaced by bone tissue.

Primary Ossification Center

The initial region of bone formation located in the center of the diaphysis during endochondral ossification.

Secondary Ossification Center

Sites of bone formation that appear in the epiphyses of long bones near or after birth.

Interstitial Bone Growth

Growth in the length of a long bone occurring as cartilage grows at the epiphyseal plate and is subsequently replaced by bone.

Appositional Bone Growth

Growth in bone thickness or diameter accomplished by osteoblasts adding bone tissue at the periosteum while osteoclasts resorb bone at the endosteum.

Comminuted Fracture

A fracture type in which the bone fragments into three or more pieces, particularly common in the elderly with brittle bones.

Compression Fracture

A fracture in which the bone is crushed, common in porous or osteoporotic bones subjected to extreme trauma.

Spiral Fracture

A ragged break occurring when excessive twisting forces are applied to a bone, common in sports injuries.

Epiphyseal Fracture

A fracture where the epiphysis separates from the diaphysis along the epiphyseal plate, tending to occur where cartilage cells are dying and matrix calcification is taking place.

Depressed Fracture

A fracture in which the broken bone portion is pressed inward, typical of skull fractures.

Greenstick Fracture

An incomplete break in which one side of the bone shaft breaks while the other side bends, common in children whose bones have relatively more organic matrix.

Osteoporosis

A bone disease resulting from low bone mass where bones become porous and thinner, making them highly vulnerable to fractures (especially at the vertebral column and neck of femur).

Paget's Disease

A chronic bone disorder characterized by excessive and haphazard rates of bone deposition and resorption, producing immature and abnormally thick bones.

Rickets

A form of osteomalacia occurring in children where bones fail to calcify fully and become soft, caused by deficiencies in calcium phosphate or Vitamin D.