Osteoclast

osteoblasts, which form bone matrix around themselves by laying down collagen fibers and depositing the hard mineral material, osteocytes, which respond to the bodies need for lower or higher circulating level of minerals contained in the bone and osteoclasts, which break down bone tissue.

The skeletal system, while appearing inert at first glance, is a dynamic organ responsible for a number of vital functions in the body; including but not limited to providing protection and support to other organ systems, as well as permitting movement through collaboration with the muscular system. At the cellular level, bone provides a reservoir of growth factors and cytokines, maintains the acid-base balance and mineral homeostasis, and is the site of hematopoeisis. Like other connective tissue

Osteoclasts will be affected indirectly through PTH upregulating RANKL production in osteoblasts. 3. The continuous high levels of PTH stimulate bone resorption by osteoclasts, but do so indirectly. The PTH will bind to the receptors located on the osteoblast, which then signal bone marrow-derived osteoclast precursors to differentiate into osteoclasts. This is done through the activity of RANKL binding to RANK. When stimulated

cells. Cells of the osteoblast lineage (osteoblasts, osteocytes) and bone-resorbing cells (osteoclasts), together with their precursor cells, are organized in specialized units called bone/basic multicellular units (BMU) (145). We have already detailed the origin of osteoblasts, responsible for bone matrix synthesis and its subsequent mineralization, and osteoblasts-derived osteocytes. On the other hand osteoclasts are large, multinucleated giant cells formed from the fusion of mononuclear progenitors

the levels of calcium and mineral deposition. When they are done filling in a cavity, the cells become flat and line the surface of the bone and then are called ‘lining cells’. They respond to hormones by making special proteins that activate the osteoclasts. Once they have secreted the matric they become less reactive and maintain the matrix. When the area surrounding an osteoblast hardens, the osteoblast becomes trapped and transforms into an osteocyte which is the mature type of bone

The skeletal system includes the osseous tissues of the body and the connective tissues that stabilize or interconnect the individual bones. The bone is a dynamic tissue. Throughout the lifespan, bone adjusts to the physiologic and mechanical demands placed on it by the processes of growth and remodeling. Bone serves the organism at multiple levels: As a system, bones permit the organism to locomote effectively and to maintain posture by bearing loads without deformation, by providing rigid attachment

bone-lining cells, which interact with pre-osteoclasts. The interaction stimulates pre-osteoclasts fusion and differentiation into multinucleated osteoclasts (Rucci, 2008) 2. Osteoclasts secrete matrix metalloproteinase and hydrogen ions via ATPase proton pumps into the area being reabsorbed, in order to lower the pH and digest the organic matrix. The osteoclasts then undergo apoptosis 3. Resorption ceases as mononuclear monocytes and macrophages replace osteoclasts to remove debris (Eriksen, 1986; Joseph

PTH is released in response to low blood calcium levels. It increases calcium levels by targeting the skeleton, the kidneys, and the intestine. In the skeleton, PTH stimulates osteoclasts, which are cells that cause bone to be reabsorbed, releasing calcium from bone into the blood. PTH also inhibits osteoblasts, cells which deposit bone, reducing calcium deposition in bone. In the intestines, PTH increases dietary calcium absorption

PART 1 INTRODUCTION Our group has been given the task for subject Anatomy and Physiology to do a research about disease.The title of our study is Osteoporosis.The aim of our assignment is to find the information about the clinical condition that change the normal structures of the bones and how the disease affect our daily life. Osteoporosis is a disease that arise when our normal structures of the bone changes as it becomes fragile and break easily.One interesting fact is that, almost one in two

Bone Lit Review Introduction - Skeletal bone is a dynamic tissue structure that constantly undergoes changes and remodeling throughout someone’s lifespan. Skeletal bones is a mechanical support for locomotion and protecting the organs. Muscle tendons and ligaments insert onto the bone. It is only present in vertebrates. - Bone tissue is made up mainly of fibrous collagen connective tissue surrounded by a calcium phosphate-like mineral. It is hollow shaped structured that cannot swell or shrink