MOLECULAR MECHANISM OF BONE FORMATION
Arunava Seth 16IP009
INTRODUCTION
Skeletal system is an integral part of vertebrates, and essential for crucial activities. It not only provides a hard frame to body and protects vital soft organs, it also is required for locomotion, storage of minerals, especially calcium in body and sheltering hematopoietic stem cell in body. Bone is actually a type of dense connective tissue, with honeycomb-like matrices, the reason behind it’s rigidity.
Ossification is the process of bone tissue formation. This can be formation of new bone during development. But it is also synonymous with bone remodeling, another important phenomenon of bone metabolism. Bone remodeling is removal of mature bone tissue from skeleton
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The most important being Wnt signaling pathway, prominently the Wnt canonical pathway (i.e. Wnt/B-catenin). It has been reported both in human and mice that loss of function mutation in co-receptor of Wnt (LRP5) causes osteoporosis, and gain of function mutation of same receptor causes high bone mass (15). This clearly indicates Wnt signaling is involved in bone formation. The exact mechanism is yet to be deciphered, in fact the identity of the Wnt ligand from the 19 Wnt ligands human produced is yet to be …show more content…
Beginning with commitment of mesenchymal cell to form cartilage cell. Factors involved in this are Pax1 and Scleraxis which are secreted by nearby mesodermal cells. The next stage is condensation of these committed cells to form compact nodules and form chondrocytes. Important molecule in this stage is N-cadherin. Also, there are some reports which points at involvement of SOX9. Next stage is endochondral ossification, the chondrocytes proliferate rapidly to form the model for the bone. The chondrocytes secrete a cartilage-specific extracellular matrix. Following stage, the chondrocytes stop dividing and increase their volume and become hypertrophic chondrocytes. These are large chondrocytes with altered the matrix they produce (adding collagen X and more fibronectin) and enable it to become mineralized by calcium carbonate. The finale phase is invasion of the cartilage model by blood vessels. The hypertrophic chondrocytes die by apoptosis. This space will become bone marrow. As the cartilage cells die, a group of cells that have surrounded the cartilage model differentiate into osteoblasts and started making bone matrix. Gradually all the cartilage is replaced by bone. Various bones are produced in this way, most notably the vertebral column, the pelvis, and the
Endomysium is found within a muscle and it contains nerves and capillaries. It is a fine layer of connective tissue that extracts each individual myocyte. P5 – Describe the sliding filament theory, giving a step by step process.
The deformation known as clubfoot is a standout amongst the most widely recognized birth imperfections including the musculoskeletal framework. It presents intrinsic dysplasia of every single musculoskeletal tissue distal to the knee. It is a deformity in which the foot is twisted so that the sole cannot be placed flat on the ground. Understanding the microscopic structure of diseased tissues that characterize clubfoot are very important areas of research. The major component of the ligament, muscle, tendon, bone and joint cartilage involved in clubfoot is collagen.
Bones are living tissue composed of living cells because of this they are a complex source of a wide variety of nutrients. They contain minerals which are embedded in protein, fat and fat soluble vitamins. They are a great source of calcium, copper, iodine, iron, magnesium, zinc, and manganese. The central part of most bones contain marrow which is a highly nutritious source of blood forming elements. They also provide natural antioxidants including enzymes.
Chapter six welcomes us into the skeletal system by presenting functions,types,structure, and development of bones. We are also presented the ideas of fractures and even the spine- curling snap of a broken bone which means a band aid simply won 't do! For example, Hematoma formation , Fibrocartilaginous callus, Bony callus ,and Remolding must occur to heal ,aka 3-10 weeks in a signature infested cast ,and if the break eventuated* on your arm, a complementary farmer 's tan. The Axial Skeleton makes an appearance by explaining itself as lying in the middle of the body and consisting of the skull, hyoid bone, vertebral column, thoracic cage, and middle ear bones. The complexity, physiology and delicate fashions of each member of this group is expressed.
• Hip bone • Sternum • Skull • Ribs • Vertebrae • Scapula • The ends of long bones Red marrow is so valuable because it is where blood stem cells are found. Bone broth rich in red marrow provides those stem cell factors which ultimately build your body’s strength and support your immune function A dash of apple cider. ; Bone is an excellent source of calcium and phosphorus, and to a lesser degree, magnesium, sodium, potassium, sulfate and fluoride In the digestion process, hydrochloric acid helps to break down food in the stomach but is also necessary to extract elemental minerals from food.
The objective of the virtual lab on bones consisted of identifying the major bones of the human body. We had to place the major bones of the body in the correct anatomical position. The key terms included the axial skeleton which includes the skull and the bones that support it, such as, the vertebral column, ribs, and sternum. The appendicular skeleton includes the bones of the limbs and the structures that support them such as, the scapula and pelvic bones.
Fibrodysplasia Ossificans Progressiva which is sometimes referred to FOP is a very rare genetic disorder in which bones grow uncontrollably to the point of causing disability (Fibrous Dysplasia). As one of the rarest and most disabling diseases, FOP causes bone to form in and over muscles, tendons, ligaments, and other connective tissues (What is FOP). Bridges of this extra bone develops across joints which causes immobility (What is FOP). These bridges also create a second skeleton that imprisons the body in bone.
Materials and Methods A frog leg was used for the muscle in the experiments. The skin was removed to expose the gastrocnemius, and the bone was severed just below the achilles tendon. The femur was cut just above the knee, and the tibiofibula was severed just below the knee. Ringer 's solution was applied to the muscle to keep the muscle moist. The procedures were done using a power lab, and a force transducer with a micropositioner.
Osteogenesis Imperfecta is a disorder of the bones which causes the bones to be very weak and fragile. The bones are weak due to poor quality or absence of collagen produced by the body. Usually this disease is inherited by the parents due to a genetic mutation. Osteogenesis imperfecta is usually present at birth.
The skeleton is made up of bones, which provide support and shape to the body. They play a key role in protecting soft internal organs, such as the brain and heart from injury. Together with muscles, strong bones assist the body to move freely and easily. People have their strongest, most dense bones in their thirties. However, once a person starts to age, the bones start to deteriorate, which puts one at high risk of fractures, disease and breakage.
The FGFR3 protein spans across the cell membrane resulting in one end inside the cell and the other outside the cell allowing the protein to interact with growth factors outside the cell and receive signals for growth and development. The FGFR3 protein in the bone cells help control bone growth through a process previously mentioned called ossification, where cartilage is transformed into bone using calcium. When growth factors bind to the FGFR3, the protein is activated and FGFR3 is able to regulate ossification. When the Gly380Arg mutation occurs, it results in the FGFR3 protein being absent or damaged therefore preventing it from interacting with external growth factors causing the loss of control of ossification. This causes problems during bone development where cartilage fails to turn into bone.
Collagen, like rope, aims to maximize bones elasticity. And cartilage acts as a buffer. Together these molecules cooperate in order to give bones structure, strength, and support. This relates to animals in the sense that all “animals have molecules that lie between their cells, specifically collagens and proteoglycans.” Through the molecules, cells are able to communicate amongst each other thereby knowing when and how to change their behavior.
Low vitamin D intake also played a major role in a lack of bone density during this
Osteoporosis Osteoporosis is a disease of the bones. It makes the bones brittle and weak, making people more vulnerable to breaks and fractures. Around the world the rates of osteoporosis is rising, in men and women. The numbers have skyrocketed in the past few years. For several years, the focus has been on women, but it seem that the rates of this disease are slowly rising in men as well.
The role of ZPA in limb development Introduction: When we take a walk, draw, kick a ball, or stretch our arms out to give someone a hug, we are using one of the remarkable products of nature’s biological processes – our limbs. We may take our arms and legs for granted, but the developmental steps that are required for these appendages of our bodies for form is nothing short of amazing. In looking at the human embryo, scanning electron micrographs show upper limb buds appearing on day 24 of embryonic development and lower limb buds appearing on day 28 as projections on either side of the lateral body wall (Larsen, 2015). These initial limb buds are formed from a core of mesodermal cells derived from the lateral plate mesoderm surrounded by