Bones Flashcards
what is the compound that makes up the inorganic component of the extracellular matrix of bone
calcium hyroxyapatite
what cell is responsible for bone synthesis
osteoblast
what cell is responsible for bone breakdown
osteoclast
what cell is responsible for bone maintaince (also a mature osteoblast)
osteocyte
what is the name of bone stem cells
osteogenic cells
what chemicals do osteoclasts use to break down bone
acid and carbonic anhydrase II
where is compact bone found
diaphysis
what is the name of the repeating structure in compact bone
Haversian system or osteon
what is the name of the structure that surrounds compact bone
periosteum
where is soft bone found
epiphysis
what is the name of the porous structure in soft bone
trabeculae
what is the function of red bone marrow
haemopoeitic tissue
what is yellow bone marrow made of
fat adipose tissue
what process form the skull and clavicle
intramembranous ossification
what is the name of the organic material osteoblasts secrete in intramembranous ossification
osteoid
outline the 4 steps of lengthwise bone growth
- resting cartilage
- chondrocytes cause cartilage atrophy
- cartilage dies
- cartilage calcifies
what is the location of lengthwise bone growth
epiphyseal plate
outline the 5 steps of widthwise bone growth
- osteoblast secrete bone matrix
- matrix forms a groove around blood vessels
- remodelling to form osteon
outer lamellae laid down
what 2 ways does physical activity affect bone growth
stimulates bone growth and encourages remodelling
why is bone remodelled when there is a change in physical activity type
trabeculae are along lines of stress
how does PTH impact bone
breakdown
how does calcitonin impact bone
formation
what is role of insulin in bone maintenance
synthesises proteins for bone growth
what is role of thyroid hormone in bone maintenance
stimulates osteoblasts
what is role of oestrogen in bone growth
stimulates or stops growth
relevance of vitamin A in bones
enhances osteoblast activity
relevance of vitamin C in bones
collagen synthesis
relevance of vitamin D in bones
calcium reabsorption
relevance of vitamin K and B12 in bones
synthesises bone proteins
relevance of manganese in bones
activates enzymes used in formation
outline the 5 stages of bone remodelling
- quiescence
- osteoclasts digest bone
- macrophages clean up
- osteoblasts lay down new bone
- new bone mineralises
what is the name of the new bone that osteoblasts lay down in fracture repair
hard callus
first stage of fracture repair
haematoma- to stop bleed
second stage of fracture repair
inflammation- clean up damaged tissue and soft callus laid
what cells lay down soft callus in inflammatory stage of fracture repair
chondrocytes
third stage of fracture repair
hard callus
what cells lay down hard callus in fracture repair
osteoblasts
fourth stage of fracture repair
remodelling
what is the name of the process that forms long bone
endochondrial ossification
name of the initial bone model in endochondrial ossification
hyaline cartilage model
