biological properties and remodelling of bone Flashcards
what hormones are involved in the regulation of calcium?
calcitonin, parathyroid hormone, 1, 25 diOH vitamin D and oestrogen
what percent of bone is protein (osteoid)
25%
what percent of bone is mineral (calcium and phosphate)
75%
what type of collagen is the protein matrix largely compromised of?
type 1
what is an example of type 1 collagen abnormality?
osteogenesis imperfecta - brittle bone disease
what is hydrated calcium and phosphate called?
hydroxyapatite
where does rickets effect on bones in growing children?
at the end plates of bones leading to bowing of bones.
what are the two types of bones called?
trabecular
cortical
what system is the whole thing on cortical bone called?
Haversian system
how do osteoclasts resorb bone?
by producing acid to remove the mineral and producing proteolytic enzymes to digest the matrix
how does oestrogen affect bone growth?
oestrogen inhibits ostetoclasts - menopause causes a decrease in oestrogen
what is osteoporosis
generalised overactivity of osteoclasts
what is pagets disease
localised imbalanced resulting in increased bone turnover
what hormones increase bone density?
oestrogen/androgens
GH/IGF-1
calcitonin
what hormones decrease bone density?
thyroxine
glucocorticoids
PTH
