Anatomy Quiz 130-142 thru "green stick"

two subdivisions of the skeleton

axial and appendicular

axial skeleton

forms longitudinal axis: skull, vertebral column, ribs, sternum

appendicular skeleton

shoulder girdle(collar bone and scapula), arms, pelvic girdle, legs

parts of the skeletal system

bones, joints, ligaments, cartilage

function of bones

support, protection, movement, storage, blood cell formation(hematopoiesis)

compact bone

homogenous

spongy bone

small, needle-like pieces of bone, many open spaces, contains red marrow(blood is made here)

long bones

longer than they are wide: all bones of limbs except patella, ankle, wrist bones

short bones

cube-shaped: carpals, tarsals

flat bones

thin, flattened, usually curved: skull, ribs, sternum

irregular bones

irregular shaped, don’t fit into other categories: vertebrae, hip bones

diaphysis

shaft composed of compact bone, protected by periosteum

periosteum

outside covering of diaphysis, fibrous connective tissue membrane, nerves and blood vessels

perforating or Sharpey’s fibers

secures periosteum to underlying bone

epiphyses

ends of bones, thin layer of compact surrounding spongy, protected by articular cartilage

articular cartilage

covers the external surface of epiphyses, made of hyaline cartilage, decreases friction at joint surfaces

epiphyseal line

remnant of epiphyseal plate, seen in adult bones

epiphyseal plate

flat plate of hyaline cartilage seen in young, growing bone

medullary cavity

cavity inside of shaft, contains yellow marrow in adults and red marrow in infants

yellow marrow

mostly fat

red marrow

for blood cell formation

bone markings

sites of attachments for muscles, tendons, and ligaments & passages for nerves and blood vessels

projections or processes

grow out from the bone surface

depressions or cavities

indentations

trochanter

(projection) very large, blunt, irregularly shaped process—femur

epicondyle

(projection) raised area on or above a condyle

process

(projection) any bone prominence

facet

(projection) smooth, nearly flat articular surface

condyle

(projection) rounded articular projection

foramen

(depression) round or oval opening through a bone

meatus

(depression) canal-like passageway

sinus

(depression) cavity within a bone, filled with air and lined with mucous membrane

osteocytes

bone cells

lacunae

cavities containing osteocytes, arranged in concentric rings

lamellae

rings around the central canal(concentric circles), sites of lacunae

central or Haversian canals

opening in the center of an osteon, carries blood vessels and nerves

osteon or Haversian system

a unit of bone containing central canal and matrix rings

cannaliculi

tiny canals, radiate from the central canal to lacunae, form transport system connecting all bone cells to a nutrient supply

perforation or Volkmann’s canals

canal perpendicular to the central canal, carries blood vessels and nerves

ossification

new cartilage is continuously formed, older cartilage becomes ossified, cartilage is broken down, enclosed cartilage is digested away opening up a medullary cavity

osteoblasts

bone-forming cells, action replaces cartilage

appositional growth

bone growth in width

osteoclasts

bone-destroying cells, break down bone matrix for remodeling and release of calcium in response to parathyroid hormone

hypercalcemia

blood calcium ion level is too high, calcium deposited in bone matrix as hard calcium salts (by osteoblasts)

bone remodeling

how bones grow and repair after a bone breaks, done by osteoclasts and osteoblasts

bones are remodeled in response to two factors

blood calcium levels, pull or gravity and muscles on the skeleton

osteoporosis

a disorder in bones decrease in density and become weak and brittle

rickets

disease of children in which bones fail to calcify—bones and weight-bearing bones of the legs show definite bowing

closed or simple fracture

doesn’t penetrate skin

open or compound fracture

penetrates skin

reduction

realignment of broken bone ends

closed reduction

bone ends coaxed back into their normal position by physician

open reductions

surgery is performed and the bone ends are secured together with pins or wires

hematoma

blood-filled swelling

comminuted

bone breaks into many fragments, common in old people

compression

bone is crushed, common on osteoporotic bones

depressed

broken bone portion is pressed inward, typical of skull fracture

impacted

broken bone ends are forced into each other, common when you break a fall with outstretched arms

spiral

jagged break occurs when excessive twisting forces are applied to a bone, common sports fracture

greenstick

bone breaks incompletely, much in the way a green twig breaks, common in children

repair of bone fractures

hematoma is formed, break is splinted by fibrocartilage to form a callus, fibrocartilage callus is replaced by a bony callus, bony callus is remodeled to form a permanent patch