skeletal sysytem Flashcards
functions of the skeletal system
1) support
2) protection
3) movement
4) storage
5) blood cell production
long bone
longer than theyre wide (upper limbs)
short bone
shorter than it is long (tarsals)
flat bone
thin bones such as ribs
irregular bone
protect vital organs (cranium)
structure of a long bone
-diaphysis = the shaft and the compact bone
-epiphysis - end of the bone and its spongy bone
-epiphyseal plate = growth plate
-epiphyseal line - bone stops growing in lenght
-medullart cavity - turns from red to yellow in limbs and skull
rest in red
structure of a long bone
periosteum - outer is fibrous
- inner is single layer of bone cells including osteoblasts, osteoclasts and osteochondral progenitor cells
endosteum - similar to periosteum but more cellular. lines all internal spaces including spaces in spongy bone
strucuture of flat bones
-no diaphyses, epiphyses
-sandwish of spongy between compact bone
short and irregular bone
-> compact bone that surrounds spongy bone center of epiphyses of long bones
- no diaphyses and not elongated
growth at articular cartilage
-increases size of bones with no epiphyses (short bone)
-chondrocytes near the surface of the articualr cartilage similar to those in zone of resting cartilage.
factors affecting bone growth
hormones - growth hormone from anterior pituaitary. stimulates interstital cartiage growth and appositional bone growth
-thyroid hormone required for growth of all tissues
-sex hormones such as oestrogen and testosterone
mechanical stress and bone strength
-stress causes bone remodeling to: increase bone mass (density)
-align trabeculae with stress
-changes causes by osteoblast activity
the effects of aging on skeletal sysytem
-bone matrix decreases. more brittle due to lack of collagen
-bone mass decreases. highest around 30. men denser (test)
