bone pathology

Question 1

roe of osteoclasts

Answer 1

bone resorbing = lysosomes to digest
fusion of monocytes = multinucleated cell
@ edges of bone in resorption pits

Question 2

role of osteoblasta

Answer 2

bone forming
calcification
some differentitate into osteocutes
@ edfe of bone (periosteum.endosteum)

Question 3

regualtion of bone remodelling

Answer 3

endocrine, paracrine (RANKL, RANK, OPG), medication

Question 4

what is bone resorption controlled by

Answer 4

RANK:OPG ratio
ostecoclast activation = bone resoroption
oclast inhib=no resorption

Question 5

what is bone strength determined by

Answer 5

STRENTFH = QUALITY + DENSITY

Question 6

what is osteoporosis characteristiics

Answer 6

systemic skeletal disorder = decrease in total bone mass density
loss of BMD< microstructure, brittel + fragile + fracture
caused by change in formation + resorption balance

Question 7

describe risk factors for post menopausal osteoporosis (type 1)

Answer 7

late menarche, early menopause, osetrogen deficiency, dec ca2+, dec vit D, underweight, dec peak bone mass

Question 8

non-modifiable and modifiable risk factors for osteoporosis and osteopenia (low BMD but not low enough for osteporosis)

Answer 8

non = age, ethcnicity, fam, malabsorption, chronic, ling terms meds, fracturs, osteomalcia
modifiable = dec BMD, low body mass, sedentary lifestyle, low ca2+ + vit D

Question 9

describe patho of osteoporsis

Answer 9

imbalance in bone formation + resorption
diamateer increases = thinning of bone and loss of trabeculae
inc ostecolasts + dec osteoblasts
trabecular bone initially -> cortical bone = decrease density wtih normal mineral content

Question 10

what are osteomalacia and rickets

Answer 10

osteomalacia = abnormal mineralisation pf osseous ,atrix + bone softening
rickets = same but children = porrt mineratlisation of cartilage in epiphyseal growth plate
caused by vit D deficiency

Question 11

describe patho of rickets

Answer 11

ossification = oblasts deposit osseous tissue + chodrocytes degen + calcify -> bone
hypertrophy = chon mature, enlarge, calcium deposited into matrix
proliferation = chondrocytes divide by mitosis
resting cartilage = chrondrocytes differntiate
= normal but rickets gets abnormalities

Question 12

morphologicao cahgnes in rickets

Answer 12

defective mineralisation = dec mineraralised trabecular bone
disorganisation growth plate
dec longitudainal growth
widenig of epiphysela regions