Skeletal System HAP

206 and 6

206 and 6

how many bones are in the human body? how many different bone shapes?

the pelvis

what’s the most prominent way to identify a female vs male skeleton?

axial skeleton

long axis (skull, vertebral column, rib cage), function is to protect

appendicular skeleton

limbs and girdles, function is to help move

support

structural support for the body and cradles soft organs

protect

vital organs and soft tissues

movement

muscles and moves bones

storage

minerals (CA2+ salts, phosphorus) and growth factors, and fat (triglycerides) located in yellow bone marrow

support, protect, movement, storage, blood cell formation, leverage

SPMSBL

long bones

long and slender; in the limbs, soles, palms and phalanges

flat bones

thin, parallel surfaces; in roof of skull, sternum, ribs, scapula; provides protection; large surface area for attachment of muscles

sutural bones (wormian bones)

small, flat, irregularly shaped; found between flat bones of skull

irregular bones

complex shapes with short, flat, notched or ridged surfaces; in vertebrae, pelvis, and some skull bones

short bones

small and boxy; in wrist bones and ankle bones

sesamoid bones

small, flat, shaped like a sesame seed; in kneecaps, some bones in hands and feet

compact bone (cortical)

outer layer- dense and solid. surrounds the marrow cavity

spongy bones (cancellous)

inner layer- open spaces, marrow. no marrow cavity

diaphysis

tubular shaft

epiphysys

expanded area at each end of the diaphysis

metaphysis

thin area that connects the epiphysis to the doaphysis

bone histology

study of microscopic structure of tissues

matrix

an environment or medium in which something develops

four

how many characteristics of bones are there

matrix composition

(Ca3(Po4)2) makes up about 2/3 of bone, about 1/3 of bone consists of collagen fibers (protein) and about 2% of bone mass is cells

can withstand compression. will shatter when exposed to bending, twisting, or sudden impacts

what can calcium phosphate withstand?

stronger than steel when subjected to tension. easily tolerate bending and twisting, but when compressed, they bend out of the way

how are collagen fibers/protein strong and flexible?

osteocytes

mature bone cells, maintain mineral and protein content of surrounding matrix

osteoblasts

make new bone matrix- process called osteogenesis. form directly from stem cells

osteoprogenitor cells

stem cells that give rise to osteoblasts

osteoclasts

remove and recycle bone matrix, process called osteolysis

osteon (haversion system)

basic functional unit of mature compact bone

haversian canal/central canal

osteocytes are arranged in layers around this

where stresses arrive from limited directions

where/when is compact bone thickest?

15 times your body weight through long axis

how much can your femur withstand?

they form struts and plates called trabeculae

how are lamellae arranged

no

is there blood supply in spongy bone?

red bone marrow

forms blood cells. found in greater quantities in juvenile bones- turns into yellow marrow as you age

yellow bone marrow

made up of adipose tissue- fat storage for energy reserve

periosteum

isolates bone from surround tissue, provides route for circulatory and nervous supply, actively participates in bone growth and repair

endosteum

lines marrow activity, active during bone growth, repair, and remodeling. incomplete layer of osteoprogenitor cells