Introduction of Human Body & Structure of cell.pptx
Formation of Bone
1.
2. General overview: Bone
Specialized connective tissue
Components of bone:
Cell:osteogenic
cell,osteoblast,osteocytes,osteoclast
Fibres:collagen type –I
Ground substanse:chondroital sulphate,keratin
sulfate and glycoprotein
Minerals:calcium phosphate,hydroxy apatite
crystal of calcium phosphate
3. Formation of bone:
Mesodermal in origin
Formed by process of ossification
a. Endochondrial ossification(cartilagenous
model)
b. Intramembranous ossification(membranous
model)
4. Law of ossification:
secondary center which appears first unites
last with diaphysis and secondary center
which appears last unites first with diaphysis
Exception: Fibula
Primary center forms diaphysis whereas
secondary center forms epiphysis
5. 1.Endochondrial ossification:
Begins at second month of embryonic
development
Hyaline cartilage is subsequently replaced by
bone
Leads to Growth in length and width of bone
Bones formed are known as cartilage bones
Formation of short and long bones.
14. Intramembranous ossification:
Mesenchymal cells directly converts to
osteoblasts with capillaries in center of
ossification
Mostly forms flat bones
e.g: formation of mandible, maxilla, clavicle
and most of flat bones of skull
Begins at 8th week of development
19. Hormonal regulation of bone
formation:
1) Human growth hormone:
Bone growth before puberty
2) Sex hormones(testosterone and estrogen)
Development of typical male and female
shaped skeleton after puberty.
3)Parathyroid hormones:release of calcitonin
21. REFERENCES:
Langman’s medical embryology,9th edition
Singh Inderbir, G.P pal, human embryology, ninth
edition,2012
Keith L.moore, The developing human, clinically
oriented embryology,8th edition
Krishna Garg,Indira Bahl,Mohini Kaul A text book
of histology,a colour atlas and text, 3rd edition
Basic histology, text and atlas,11th edition,2005
penny(2012), bone development, retrieved on 26th
April, 2014.