bone hx

inorganic comp

• STRENGTH (2/3)

• hydroapatite (Ca & PO4)

organic comp

• FLEX. (1/3)

• cells, collagen (FLEX.) intercell. matrix

mems

peri & endo

1. dense CT

2. osteoprogenitor cells (becomes bone cart)

epiphysis

end - SPONGY

diaphysis

shaft - COMPACT

epiphyseal plate

cart in growing bone - grows length

medullary cavity

middle - mostly yellow marrow (fat)

cells

blast = make

clast = break

cyte = mature - LACUNAE

osteon

cylinder unit - STRENGTH

COMPACT BONE

lamellae

rings surrounding osteon

haverian canal

middle - BV & nerves

BONE IS VASC

cartilage

AVASC - synovium

cart comps

1. intercell. matrix = chondroitin SO4

2. cells = chondro - cytes & blasts

3. peri = chondrium

hyaline

art surface

nose, trachea, bronchi, costal

fibrocartilage

compression

vert, pubic symphysis, menisci

elastic

flex

eustachian tube, ex. ear, epiglottis

osteogenesis

bone formation

ossification

oblast makes osteoid

ORG

intramembranous ossification

bone develops in-between fibrous CT sheets

fetal protection bones

endochondral ossification

oblasts replace hyaline

up to 25 - most bones

1. BV

2. bone → cart in med cav

3. increase diaphysis

4. increase epiphysis

5. increase bone l/w

calcification

deposit Ca - hardens bone

INORG

bone growth

• Ca

• PO4

• vit A & C - make healthy oblast

• vit D - increase Ca absorp.

parathyroid

stim oclast & Ca absorp.

calcitonin

inhibits oclast

thyroid

growth hormone

stim oblast

pituitary

sex hormones

stim oblast