Anatomy Quiz

axial Skeleton

bones that form the longitudinal axis of the body

apendicular skeleton

bones of the limbs and girdles

skeletal system

joins, cartilages, and ligaments

compact bone

dense; looks smooth and homogeneous

spongy bone

composed of small needle like pieces of bone and lots of open space

long bone

longer than they are wide

short bone

generally cube shaped and mostly spongy bone

flat bone

thin, flattened, and usually curved; two thin layers of compact bone sandwiching a layer of spongy bone between them

irregular bone

bones that do not fit into any other categories

diaphysis

shaft of a long bone that makes up most of the bone’s length and is composed of compact bone

periosteum

fibrous connective tissue that protects the long bone

perforating

secure the periosteum to the underlying bone

epiphyses

ends of the long bone; consists of thin layer of compact bone enclosing an area of spongy bone

articular cartilage

covers the external surface of the epiphysis; glassy hyaline cartilage that creates a smooth, slippery surface that decreases friction at joint surfaces

epiphyseal line

thin line of bony tissue spanning the epiphysis that looks a bit different from the rest of the bone in that area; shows where epiphyseal plate once was

epiphyseal plate

flat plate of hyaline cartilage seen in young, growing bone; causes lengthwise growth of long bone; end of puberty causes plates to be replaced by bone leaving only the line

yellow marrow/ medullary cavity

in adults the cavity of the shaft is mainly a storage area for adipose tissue

red marrow

in infants: forms blood cells

in adults: confined to the cavities of spongy bone of flat bones and the epiphyses of some long bones

bone markings

reveal where muscles, tendons, and ligaments were attached and where blood vessels and nerves passed

osteocytes

mature bone cells

lacunae

tiny cavities within the matrix of bone

lamellae

lacunae arranged in concentric circles around a central canal

haversian canal

channels in bone that contain blood vessels and nerves

osteon

each complex consisting of central canal and matrix rings

canaliculi

tiny canals that radiate outward from the central canals to all lacunae; forms transportation system that connects all bone cells to nutrient supply

perforating/ volkmann’s canal

run into compact bone at right angles to the shaft

ossification

bone formation

osteoblasts

bone-forming cells

osteoclasts

giant bone- destroying cells

bone remodeling

osteoblasts lay down new matrix and become trapped within it- essential if bones are to retain normal proportions and strength during long bone growth as the body increases in size and weight

rickets

a disease in children in which bones fail to calcify; bones soften, and weight-bearing bones of legs show a definite bowing - usually due to lack of vitamin D or calcium

fractures

a crack or break in a bone

reduction

realignment of the broken bone ends

hematoma

blood filled swelling

fibrocartilage callus

contains several elements- some cartilage matrix, some bony matrix, and collagen fibers- and acts to “splint” the broken bone

bony callus

the fibrocartiliage callus is gradually replaced by one made of spongy bone

sharpeys fibers

secure the periosteum to the underlying bone