bone anatomy and physiology Flashcards
diagram
Osteocytes
As the osteoid mineralises, the osteoblasts become entombed between lamellae in lacunae where they mature into osteocytes. They then monitor the minerals and proteins to regulate bone mass.
woven vs lamellar
Woven bone (primary bone) – Appears in embryonic development and fracture repair, as it can be laid down rapidly. It consists of osteoid (unmineralised ECM), with the collagen fibres arranged randomly. It is a temporary structure, soon replaced by mature lamellar bone.
Lamellar bone (secondary bone) – The bone of the adult skeleton. It consists of highly organised sheets of mineralised osteoid. This organised structure makes it much stronger than woven bone. Lamella bone itself can be divided into two types – compact and spongy.
define ossification and the different types
process of producing new bone - 2 mechanisms
endochondrial - hyaline cartilage is replaced by osteoblasts
intramembranous ossification - mesenchymal tissue (embryonic) is condensed into bone - forms flat bones such as temporal bone and scapula
primary bone is made initially and replaced with mature bone later on
where is irregular trebeculae presnt
spongy bone
bone ossification vs bone repair
woven vs lamellar bone
fragility, dysplasia, mineralisation, pyrophosphates
Bone Fragility: Increased susceptibility to fractures due to reduced bone strength. Common in osteoporosis, osteogenesis imperfecta, and osteomalacia.
Bone Dysplasia: Abnormal bone growth or development, often genetic. Examples include achondroplasia (short stature) and fibrous dysplasia (bone deformities).
Bone Mineralisation: The process of depositing minerals (calcium, phosphate) into the bone matrix. Defects in mineralization occur in rickets, osteomalacia, and hypophosphatasia.
Pyrophosphates: Inorganic compounds that regulate bone mineralization. Excess pyrophosphate can lead to calcium pyrophosphate deposition disease (CPPD), while deficiency can cause excessive bone mineralization.
