Ch 6 PHYL 141 Exam

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

channels within the bone matrix that house an osteocyte's cytoplasmic extensions used for communication and nutrient exchange

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 containing blood vessels nerves and lymphatic vessels; also called the Haversian canal

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 sandwiched between two layers of compact bone 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

sheet of hyaline cartilage in the metaphysis of an immature bone that is replaced by bone tissue as the bone grows in length

epiphysis

wide section at each end of a long bone filled with spongy bone and red marrow

flat bone

thin and curved bone that serves as a point of muscle attachment and protects internal organs

fracture

broken bone

hematopoiesis

production of blood cells that occurs in red marrow

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

intramembranous ossification

process by which bone forms directly from mesenchymal tissue

irregular bone

bone of complex shape that protects internal organs from compressive forces

lacunae

spaces in bone that house osteocytes

long bone

cylinder-shaped bone that is longer than it is wide and functions as a lever

modeling

process during bone growth in which bone is resorbed on one surface and deposited on another

open reduction

surgical exposure of a bone to reset a fracture

osseous tissue

bone tissue; hard dense connective tissue that forms the structural elements of the skeleton

ossification

bone formation; also called osteogenesis

ossification center

cluster of osteoblasts found in the early stages of intramembranous ossification

osteoblast

cell responsible for forming new bone

osteoclast

cell responsible for resorbing bone

osteocyte

primary cell in mature bone responsible for maintaining the matrix

osteogenic cell

undifferentiated cell with high mitotic activity that differentiates into osteoblasts

osteoid

uncalcified bone matrix secreted by osteoblasts

osteon

basic structural unit of compact bone made of concentric layers of calcified matrix; also called a Haversian system

osteoporosis

disease characterized by decreased bone mass when bone resorption exceeds bone formation

perforating canal

channel branching from the central canal that houses vessels and nerves extending to the periosteum and endosteum; also called a Volkmann's canal

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 marking where part of the surface sticks out and serves as an attachment site for tendons and ligaments

red marrow

connective tissue in the interior cavity of bone where hematopoiesis occurs

remodeling

process by which osteoclasts resorb old bone while osteoblasts form new bone to replace it

secondary ossification center

region of bone development in the epiphyses

sesamoid bone

small round bone embedded in a tendon that protects the tendon from compressive forces

short bone

cube-shaped bone approximately equal in length width and thickness that provides limited motion

skeletal system

organ system composed of bones and cartilage that provides movement support and protection

spongy bone

trabeculated osseous tissue that supports shifts in weight distribution; also called cancellous bone

trabeculae

lattice-like spikes or sections of matrix found in spongy bone

yellow marrow

connective tissue in the interior cavity of bone where fat is stored

osteoprogenitor cell

bone stem cell found in the periosteum and endosteum that can divide and differentiate into osteoblasts

hydroxyapatite

calcium phosphate crystals that provide hardness and compressive strength to bone

concentric lamellae

concentric rings of calcified bone matrix that form an osteon

trabecular bone

spongy bone composed of a network of trabeculae

ligament

connective tissue structure that connects bone to bone

tendon

connective tissue structure that connects muscle to bone

fibrocartilage

cartilage rich in collagen fibers that resists compression and is found in symphysis joints

hyaline cartilage

most abundant cartilage type found at joints and in developing bones

medullary cavity

hollow cavity within the diaphysis that contains bone marrow

metaphysis

region between the epiphysis and diaphysis containing the growth plate

growth plate

another name for the epiphyseal plate

interstitial growth

growth occurring within a tissue that increases bone length

appositional growth

growth occurring at the surface of a tissue that increases bone thickness

calcification

accumulation and deposition of calcium salts within a tissue

angiogenesis

formation of new blood vessels

periosteal bud

passageway of blood vessels extending from the periosteum into developing bone

calcified zone

region of the growth plate where calcium deposition occurs

proliferating zone

growth plate region where chondrocytes rapidly divide

hypertrophic zone

growth plate region where chondrocytes enlarge in size

resting zone

growth plate region nearest the epiphysis that anchors the epiphysis to the diaphysis

ossification zone

growth plate region where osteoblasts form new bone tissue

chondroblast

cartilage-forming cell that secretes cartilage matrix

chondrocyte

mature cartilage cell located within lacunae

Wolff's law

principle stating that bone structure strengthens in response to mechanical stress

growth hormone (GH)

hormone that stimulates chondroblast division and bone growth

insulin-like growth factors (IGFs)

potent stimulators of bone growth released in response to growth hormone

calcitonin

hormone that inhibits osteoclast activity and lowers blood calcium levels

parathyroid hormone (PTH)

hormone that stimulates osteoclast activity and raises blood calcium levels

osteitis deformans (Paget's disease)

disease involving excessive bone remodeling that produces weak disorganized bone

gigantism

excessive skeletal growth caused by excess growth hormone during childhood

achondroplasia

disorder in which abnormal cartilage growth causes shortened long bones

osteomalacia

poor bone mineralization due to inadequate calcium phosphate or vitamin D

rickets

childhood form of osteomalacia

scurvy

disease caused by vitamin C deficiency that impairs collagen formation

osteopenia

normal age-related loss of bone mass

osteogenesis imperfecta

genetic disorder causing brittle bones due to abnormal collagen production

stress fracture

fracture caused by repetitive physical stress

pathologic fracture

fracture caused by disease within bone tissue

simple fracture

fracture in which the skin remains intact

compound fracture

fracture in which bone pierces the skin

comminuted fracture

fracture producing many small bone fragments

greenstick fracture

incomplete fracture in which only one side of the bone breaks

Pott's fracture

fracture involving the bones of the ankle

transverse fracture

fracture occurring straight across the long axis of a bone

oblique fracture

fracture occurring at an angle

spiral fracture

fracture caused by twisting forces

impacted fracture

fracture in which one bone fragment is driven into another

reduction

process of realigning a fractured bone

traction

technique using pulling forces to assist fracture reduction

hematoma

localized accumulation of blood that forms the first stage of fracture healing