Anatomy_Key Terms_Ch6 Flashcards
articular cartilages
cover the ends of most bones at moveable joints
costal cartilages
connect the ribs to the sternum (breastbone)
perichondrium
layer of dense irregular connective tissue surrounding a cartilaginous structure which acts like a girdle to resist outward expansion when the cartilage is subjected to pressure and functions in the growth and repair of cartilage
chondrocytes
cells that, with an abundant extracellular matrix, make up the cartilage connective tissue
lacuna
each chondrocyte in cartilage tissue is located in a space in the matrix called a
hyaline cartilage
most abundant kind of cartilage; chondrocytes appear spherical; only fiber is a collagen unit fibril; provides support through flexibility and resilience; makes up the articular cartilage that covers the ends of adjoining bones in movable joints and the cartilaginous attachments of the ribs to the sternum, accounts for most of the cartilage found in the respiratory structures, and forms the embryonic skeleton
elastic cartilage
matrix contains many elastic fibers along with collagen fibrils; found in the epiglottis and the outer ear
fibrocartilage
resists both strong compression and trong tension forces; occurs in certain ligaments and certain cartilages that experience both of these forces; consists of thick collagen fibers surrounding the chondrocytes within lacunae; exists in the anulus fibrosus portion of the discs between the vertebrae and in the articular discs of some joints eg the menisci of the knee
appositional growth
”"”growth from outside””, chondroblasts in the surrounding perichondrium produce the new cartilage tissue by actively secreting matrix”
interstitial growth
”"”growth from within””, the chondrocytes within the cartilage divide and secrete new matrix”
calcified cartilage
not bone; crystals of calcium phosphate precipitate in the matrix of cartilage under certain conditions
osteoprogenitor cells
stem cells that differentiate into bone-forming osteoblasts
osteoblasts
cells that catively produce and secrete the organic components of the bone matrix: the ground substance and the collagen fibers
osteoid
the bone matrix secreted by osteoblasts
osteocytes (bones)
osteoblasts completely surrounded by bone matrix and no longer producing new osteoid; function to keep the bone matrix healthy
osteoclasts
cells responsible for the resorption of bone; derived from a lineage of white blood cells
compact bone
dense outer layer that looks smooth and solid to the naked eye
spongy bone
aka trabecular bone, internal to compact bone, a honeycomb of small needle-like or flat ieces called trabeculae and filled with red or yellow bone marrow
trabeculae
”"”little beams””, small needle-like or flat pieces that make the honeycomb of spongy bone”
diaphysis
shaft, forms the long axis of a long bone
epiphyses
bone ends of a long bone
epiphyseal line
remnant of the epiphyseal plate (aka growth plate) between the diaphysis and each epiphysis of an adult long bone
medullary cavity
aka marrow cavity, very center of the diaphysis of long bones is filled with yellow bone marrow
periosteum
”"”around the bone””, connective tissue membrane that covers the entire outer surface of each bone except on the ends of the epiphyses; two sublayers: a superficial layer of dense irregular connective tissue which resists tension placed on a bone during bending, and a deep layer that abuts the compact bone which is osteogenic containing osteoblasts and osteoclasts”
perforating collagen fiber bundles
thick bundles of collagen that run from the periosteum into the bone matrix, securing periosteum to the underlying bone
endosteum
much thinner connective tissue membrane covering internal bone surfaces, specifically the trabeculae of spongy bone and lines the central canals of osteons; also osteogenic
diploe
”"”double””, the internal spongy bone of flat bones”
bone markings
provide a wealth of info about the functions of bone and muscles and on the relationship of bones to their associated soft structures
osteon
aka Haversian system, long, cylindrical structures oriented parallel to the long axis of the bone and to the main compression stresses; like miniature weight-bearing pillars; a group of concentric tubes resembling the rings of a tree trunk in cross section
lamella
”"”little plate””, tube of the osteoen, a layer of bone matrix in which the collagen fibers and mineral crystals align and run in a single direction; in adjacent lamellae they run in roughly opposite directions”
central canal
aka Haversian canal, core of each osteon canal, lined with endosteum, contains its own blood vessels and its own nerve fibers
perforating canals
“aka Volkmann’s canals, lie at right angles to te central canals of osteons and connect the blood and nerve supply of the periosteum to that of the central canals and the marrow cavity”
canaliculi
“thin tubes occupied by the ““spider legs”” of osteocytes (the bodies lie in lacunae)”
interstitial lamellae
groups of impomplete lamellae lying between the osteons, remains of old osteons that have been cut hrough by bone remodeling
circumferential lamellae
occure in the external and internal surfaces of the layer of compact bone; each of these lamellae extends around the entire circumference of the diaphysis
osteogenisis/ossification
names for the process of bone-tissue formation
membranous bones
develop from a mesenchymal membrane through a process called intramembranous ossification
endochondral bones
aka cartilage replacement bones, bones that develop as hyaline cartilage and are replaced thorugh a process called endochondral ossification
woven bone tissue
trabeculae are arranged in networks
endochondral ossification
all bones from the base of the skull down except the clavicle are endochondral bones; first modeled in hyaline cartilage which then is gradually replaced by bone tissue
periosteal bud
consists of a nutrient artery and vein, along with the cells that will form the bone marrow and contains osteoprogenitor cells and osteoclasts
primary ossification center
bone tissue forming around the diaphysis from the periosteum and appearing in the center of the diaphysis
secondary ossification centers
areas of bone formation in the epiphyses
epiphyseal plates
aka growth plates, are responsible for lenthening the bones during the two decades following birth
resting zone
relatively small and inactive cartilage cells nearest the epiphysis
proliferation zone
“quickely dividing chondroblasts at the ““top”” of the stack of tall columns of cartilage cells”
hypertrophic zone
older chondrocytes deeper in the stacks of cartilage cells enlarge and signal the surrounding matrix to calcify
calcification zone
cartilage matrix becomes calcified and the chondrocytes die
ossification zone
spicules (trabeculae) of calcified cartilage on the diaphysis side of the epiphysis-diaphysis junction are partly eroded by osteoclasts, then covered with bone tissue by osteoblasts, forming spicules of bone
