Human Anatomy Chapter 5

axis

1) the second cervical vertebra; has a vertical projection called the dens around which the atlas rotates 2) the imaginary line about which a joint or structure revolves

process (projection)

1)prominence 2) series of actions for a specific purpose

rickets

a disease of children in which the bones fail to calcify

epiphyseal plate

a flat plate of hyaline cartilage seen in a young, growing bone, causing the lengthwise growth of a long bone

closed (simple)fracture

a fracture in which the bone breaks cleanly and does not penetrate the skin

lacunae

a small space, cavity, or depression; lacunae in bone or cartilage are occupied by cells

ramus

armlike bar of bone

greenstick fracture

bone breaks incompletely, much in the way a greentwig breaks

comminuted fracture

bone breaks into many fragments

compression fracture

bone is crushed

spongy bone

bone tissue that is composed of small needle like pieces of bone and lots of open space

compact bone

bone tissue that is dense and looks smooth and homogeneous

osteoblasts

bone-forming cells

irregular bones

bones that are not long, flat, or short (vertebrae, hip, spinal column)

flat bones

bones that are thin, flattened, and usually curved. They have 2 thin layers of compact bone with spongy bone between them

long bones

bones that are typically longer than they are wide with a shaft with heads at both ends (mostly compact bone)

head

bony expansion carried on a narrow neck

impacted fracture

broken bone ends are forced into each other

depressed fracture

broken bone portion is pressed inward

meatus

canal-like passageway

sinus

cavity with a bone, filled with air and lined with mucuous membrane

lamella

concentric circle in which lacunae are arranged in a compact bone

short bones

cube-shaped and mostly spongy bone

disphysis

elongated shaft of a long bone

canaliculi

extremely small tubular passage or channel

fontanels

fibrous membranes at the angles of cranial bones that accommodate brain growth in the fetus and infant

open (compound) fracture

fracture in which the broken bone ends penetrate through the skin

groove

furrow

foreman

hole or opening in a bone or between body cavities

cribriform plates

holey areas on the crista galli that allow nerve fibers to carry impulses from the factory receptors of the nose to reach the brain

depression (cavity)

indentations in the bone

osteoclasts

large cells that reabsorb or break down bone matrix

tuberosity

large, rounded projection; may be roughened

osteocytes

mature bone cell

line

narrow ridge of bone; less prominent than the crest

crest

narrow ridge of bone; usually prominent

fissure

narrow, slitlike opening

intervertebral discs

pads of flexible fibrocartilage that separate the single vertebrae, cushion it, and absorb shocks

spiral fracture

ragged break occurs when excessive twisting forces are applied to a bone

epicondyle

raised area on or above a condyle

condyle

rounded articular projection

fossa

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

spine

sharp, slender, often pointed, projection

tubercle

small, rounded projection or process

facet

smooth, nearly flat articular surface

epiphyses

the end of a long bone

atlas

the first cervical vertebra; articulates with the occipital bone of the skull and the second cervical vertebra

true ribs

the first seven pairs of the ribs that attach directly to the sternum by costal cartilages

floating ribs

the last two pairs of false ribs that lack the sternal attachments

false ribs

the next five pairs of ribs that either attach to the sternum indirectly or are not attached at all

appositional growth

the process by which bones increase in diameter

ossification

the process of bone formation in which bones develop using hyaline cartilage structures as their "models"

open reduction

the realignment of broken bone ends in which surgery is performed and the bone ends are secured together with pins or wires

closed reduction

the realignment of broken ends in which the bone ends are coaxed back into their normal positions by a physician's hands

trochanter

very large, blunt, irregularly shaped process (examples are on the femur)