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weight of the skeletal system
20 lbs
functions of skeletal system
-provides the framework/support of the body -produces blood cells -provides protection for the organs -helps us breathe -stores minerals
production of blood cells
hematopoiesis
minerals that bones store
calcium and phosphorus
osteocytes
mature bone cells
% of bone weight that comes from mineral content
60-70
% of bone weight that comes from collagen and water
30-40
collagen
a protein that makes bones flexible
reason children's bones are more flexible than adults
they have a higher collagen and water levels
shapes of bones
-long bones -short bones -flat bones -irregular bones
long bones
longer than they are wide
examples of long bones
arms and legs
short bones
cube shaped; made mostly of trabecular bone
examples of short bones
wrist and ankles
flat bones
flat or curved, or platelike
examples of flat bones
sternum, skull, and ribs
irregular bones
fit together like a jigsaw puzzle
examples of irregular bones
vertebrae and hips
types of bone tissue
cortical and trabecular
cortical bone
-dense -outer layer of the bone (hard, protective) -higher mineral content stronger than trabecular bone
trabecular bone
-spongy bone -porous -makes up the interior bone -more flexible than cortical -makes bone lighter in weight
periosteum
outer covering of the bone
epiphysis
ends of the bone
diaphysis
middle part of the bone (shaft)
epiphyseal plate
growth plate
medullary cavity
hollow area in diapysis
endosteum
lines the medullary cavity
parts of periosteum
-blood vessels -lymph vessels -nerves
parts of epiphysis
-trabecular bone tissue -filled with red marrow -covered with articular cartilage
yellow marrow in an emergency
converts to red bone marrow to help in RBC production
parts of diaphysis
is hollow
parts of medullary cavity
-filled with yellow bone marrow -blood vessels -stores fat
function of epiphyseal plate
bone fuses together when you are done growing
Studied by 29 People