Bone provides shape and support for the body, as well as protection for some organs. Bone also serves as a storage site for minerals and provides the medium—marrow—for the development and storage of blood cells. A very large cell formed in bone marrow, its function is to absorb and remove unwanted tissue. Found within the bone, its function is to help maintain bone as living tissue. Found in bone marrow, its function is to produce red blood cells, white blood cells, and platelets.
It contains blood vessels and nerves that provide nourishment and sensation to the bone. With out it our bones would not receive nutrients, would be ill protected and with out a means to repair itself, leaving us brittle, delicate and frail. Initally, the bleeding sources from the blood vessels in the bone and periosteum. This forms a hematoma beneath the surface of the periosteum.
This article has been cited by other articles in PMC. Abstract Nearly every bone in the body is invested in periosteum. Histology of the periosteum Periosteum can be thought of as consisting of two distinct layers, an outer fibrous layer and an inner layer that has significant osteoblastic potential.
Outer layer The outer fibrous layer can be subdivided into two parts. Inner cambium layer The cambium layer is highly cellular and is composed of mesenchymal progenitor cells, differentiated osteogenic progenitor cells, osteoblasts and fibroblasts in a sparse collagenous matrix. Developmental anatomy of the periosteum Anatomically, periosteum covers the majority of the bony structures with the exception of their intra-articular surfaces and sesamoid bones. Periosteal substitutes The periosteum and its precursor, perichondrium, have two major functions aside from lending some structural integrity to the skeleton.
Appositional growth Secondary centers of ossification are frequently largely intra-articular structures and therefore, like sesamoid bones, are largely devoid of periosteum. Fracture healing While it is true that periosteum and periosteally derived cells are major contributors to fracture healing, it is by no means the only mechanism available to the osseous structures for its repair. Conclusion The periosteum is a complex structure composed of an outer fibrous layer that lends structural integrity and an inner cambium layer that possesses osteogenic potential.
Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author s and source are credited.
References 1. Osteogenic capacities of tibial and cranial periosteum: a biochemical and histologic study. J Craniofac Surg. Localization of chondrocyte precursors in periosteum. Osteoarthritis Cartilage. Ultrastructure of the periosteum from membrane bone. J Anat. Jaffe H. Metabolic, degenerative and inflammatory diseases of bones and joints.
Periosteum: biology, regulation, and response to osteoporosis therapies. Pericytes as a supplementary source of osteoblasts in periosteal osteogenesis. Clin Orthop Relat Res. Uddstromer L. The osteogenic capacity of tubular and membranous bone periosteum. A qualitative and quantitative experimental study in growing rabbits. Scand J Plast Reconstr Surg. Histogenesis, anatomy and physiology of bone.
In: Resnick D, editor. Diagnosis of bone and joint disorders. Philadelphia: W. Saunders Company; Williams P, Warwick R. Williams N. Textbook of rheumatology.
Organization and cellular biology of the perichondrial ossification groove of ranvier: a morphological study in rabbits. J Bone Joint Surg Am. Davies DV. The anatomy and physiology of joints. In situ examination of the time-course for secondary mineralization of Haversian bone using synchrotron Fourier transform infrared microspectroscopy.
Matrix Biol. The vascularized medial femoral condyle periosteal bone flap for the treatment of recalcitrant bony nonunions. Ann Plast Surg.
MR imaging anatomy of the infant hip. Human femoral neck has less cellular periosteum, and more mineralized periosteum, than femoral diaphyseal bone. Evidence for bone formation on the external "periosteal" surface of the femoral neck: a comparison of intracapsular hip fracture cases and controls. Osteoporos Int. Evidence of a hypermineralised calcified fibrocartilage on the human femoral neck and lesser trochanter.
Fetal and postnatal development of the patella, patellar tendon and suprapatella in the rabbit; changes in the distribution of the fibrillar collagens.
Andersen H. Histochemical studies on the histogenesis of the knee joint and superior tibio-fibular joint in human foetuses. Acta Anat Basel ; 46 — Prepatellar quadriceps continuation: MRI of cadavers with gross anatomic and histologic correlation.
The nerves sense pain, and it appears the nerves also play roles in regulating blood supplies and in bone growth, hence their concentrations in metabolically active sites of the bone. Watch this video to see the microscopic features of a bone. A hollow medullary cavity filled with yellow marrow runs the length of the diaphysis of a long bone. The walls of the diaphysis are compact bone. The epiphyses, which are wider sections at each end of a long bone, are filled with spongy bone and red marrow.
The epiphyseal plate, a layer of hyaline cartilage, is replaced by osseous tissue as the organ grows in length. The medullary cavity has a delicate membranous lining called the endosteum. The outer surface of bone, except in regions covered with articular cartilage, is covered with a fibrous membrane called the periosteum.
Flat bones consist of two layers of compact bone surrounding a layer of spongy bone. Bone markings depend on the function and location of bones. Articulations are places where two bones meet. Projections stick out from the surface of the bone and provide attachment points for tendons and ligaments. Holes are openings or depressions in the bones. Bone matrix consists of collagen fibers and organic ground substance, primarily hydroxyapatite formed from calcium salts. Osteogenic cells develop into osteoblasts.
Osteoblasts are cells that make new bone. They become osteocytes, the cells of mature bone, when they get trapped in the matrix.
Osteoclasts engage in bone resorption. Compact bone is dense and composed of osteons, while spongy bone is less dense and made up of trabeculae. Blood vessels and nerves enter the bone through the nutrient foramina to nourish and innervate bones. If the articular cartilage at the end of one of your long bones were to degenerate, what symptoms do you think you would experience?
In what ways is the structural makeup of compact and spongy bone well suited to their respective functions? The surface features of bones vary considerably, depending on the function and location in the body. There are three general classes of bone markings: 1 articulations, 2 projections, and 3 holes. These surfaces tend to conform to one another, such as one being rounded and the other cupped, to facilitate the function of the articulation. A projection is an area of a bone that projects above the surface of the bone.
These are the attachment points for tendons and ligaments. In general, their size and shape is an indication of the forces exerted through the attachment to the bone.
0コメント