Bone Development George Fishback Chelsea Marsh Paulina Cywinski

Bone Development George Fishback Chelsea Marsh Paulina Cywinski Colin Brannagan O’Mani Golston Stephannie Grybet Alec Mackethon

What is Ossification? • The process of laying down/creating new bone. • • Bones affected Third month of embryonic development – • Fourth month – • Bone of the lower limbs and os coxae become completely ossified 23 to 25 years – • Bone of upper limbs and scapulae becoming completely ossified 18 to 23 years – • Ossification is spreading rapidly from the ossifcation centers and various bones are becoming ossified 17 to 20 years – • Secondary ossification centers appear in the epiphyses 5 years to 12 years in females, 5 to 14 years in males – • Most primary ossification centers have appeared in the diaphyses of bone. Birth to 5 years – • Ossification in long bones beginning Bone of the sternum, clavicles, and vertebrae become completely ossified By 25 years – Nearly all bones are completely ossified

Formation of hand…

Intramembranous Ossification • Formation of bone spicules • Formation of woven bone replaced by lamellar bone • Creates bone

Endochondral Ossification • One of the processes that results in the creation of bone • During fetal development • Creates Cartilage – a specialized fibrous connective tissue

Endochondral Ossification Continued • Endochondral ossification is one of two essential processes in fetal development by which bone tissue is created. Unlike intramembranous ossification, which is the other process by which bone tissue is created, cartilage is present during endochondral ossification. This process is also essential during the formation of long bones, the growth of the length of long bones, and the natural healing of bone fracture.

Osteoblasts • One of two primary cell types used to produce and maintain bone. • Cells that create bone.

Osteoclasts • The cells that reabsorb, or break down and absorb, bone tissue back into the body. • Highly specialized cells that have to work in perfect synchronization with osetoblasts.

Video • http: //www. youtube. com/watch? v=78 RBp. WS Ol 08&feature=relmfu&safety_mode=true&pe rsist_safety_mode=1&safe=active