CHP7 Bone Tissue

Embryonic mesenchyme condensing into a sheet of soft

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: eddish jelly’ that has replaced yellow reddish Gelatinous marrow of elderly marrow Bone development- 2 methods of ossification (or osteogenesis) …intramembranous & endochondral endochondral Intramembranous ossification Intramembranous Intramembranous= produces flat bones of skull & clavicle Steps of the process~ • Begins w/ embryonic mesenchyme condensing into a sheet of soft tissue (& lots of bld capillaries) • Some of sheet transforms into network of soft trabeculae, other cells differentiate into osteogenic cells • Next, osteogenic cells become osteoblasts, gathering on trabeculae & begin depositing matrix (= osteoid tissue) • Soft collagenous tissue lacking minerals • Larger trabeculae begin depositing Ca3(PO4)2, thus, osteoblasts change into osteocytes once trapped in lucanae • Concurrently, osteoclasts remodel the center for marrow spaces, while osteoblasts remodel the surface to form compact bone • Mesenchyme at the surface gives rise to periosteum Endochonral ossification Endochonral Endochondral ossification Endochondral Endochondral= produces most other bones; vertebrae, pelvic produces & limb bones limb • Mesenchyme transforms into a hyaline cartilage ‘model’ that Mesenchyme is broken down & reorganized & calcified into bone Primary ossification center= 1st step, chondrocytes w/in center Primary of model multiple & swell (forming the p.o.c.) of • Lucanae enlarge, reducing matrix & so model becomes weak • Some perichondrium cells become osteoblasts that produce Some a bony collar around model bony • Diffusion of nuts is cut off & cartilage cells die; perichondrium is Diffusion replaced w/ periosteum replaced • Buds of c.t. from periosteum grow into cartilage & penetrate Buds & breakdown lucanae…transforming p.o.c. into a cavity (p.m.s.) (p.m.s.) Endochonral ossification (cont.) Endochonral Primary marrow space= iinner cavity; osteogenic cells invade nner model & transform into osteoblasts that line the marrow space space Osteoblasts deposit osteoid tissue & then calcify it,...
View Full Document

This note was uploaded on 01/12/2014 for the course ZOO 250 taught by Professor Staff during the Fall '08 term at S.E. Louisiana.

Ask a homework question - tutors are online