Which cells are involved in the mechanotransduction of mechanical signals to stimulate bone growth as a result of physical activity?
Osteocytes, cells embedded within the mineralized matrix of bone, are becoming the target of intensive investigation [61–64]. Osteoblasts are defined as cells that make bone matrix and are thought to translate mechanical loading into biochemical signals that affect bone modeling and remodeling.
What is the effect of mechanical stress applied to bone?
Recent studies revealed the function of osteocytes as mechanosensors in the early stage of bone remodeling. Loaded mechanical stress is converted to a series of biochemical reactions, and finally activates osteoclasts and osteoblasts to cause bone resorption and formation.
What is mechanical loading in bone?
Mechanical loading is a major regulator of bone mass and geometry. The osteocytes network is considered the main sensor of loads, through the shear stress generated by strain induced fluid flow in the lacuno-canalicular system. Exercise programs proposed for bone health are tedious and compliance is usually low.
How do bones behave dynamically?
Bone therefore dynamically responds to forces and moments in various directions, translating compressive, tensile and shear strains into compression, tension, bending, shear and torsional mechanical outputs[54,55,95,97,101,112,194,205].
What is the correct sequence of steps in bone repair?
There are four stages in the repair of a broken bone: 1) the formation of hematoma at the break, 2) the formation of a fibrocartilaginous callus, 3) the formation of a bony callus, and 4) remodeling and addition of compact bone.
What bone reduces the weight of the skeleton and reduces the load on muscles?
Spongy bone reduces the weight of the skeleton and reduces the load on muscles. Spongy bone, also known as cancellous bone or trabecular bone, has increased porosity and less mineral content compared with cortical (compact) bone. Spongy bone is found in the ends of long bones.
What type of stress is bone strongest in resisting?
- Biology questions and answers.
- Bone is weakest in resisting: Tensile stress Shear stress Compressive stress Bone is equally strong in resisting all types of stress.
How does age affect bone development?
People lose bone mass or density as they age, especially women after menopause. The bones lose calcium and other minerals. The spine is made up of bones called vertebrae. Between each bone is a gel-like cushion (called a disk).
How do bone cells sense mechanical loading?
The bone cell can quickly identify the characteristics of mechanical stimuli and respond electrophysiologically in different ways, with varying degrees of ion channel activation, resulting in the hyperpolarization or depolarization of the plasma membrane.
How does bone respond to loading?
Bone responds to supraphysiological mechanical loads by increasing bone formation. Depending on the applied strain magnitude (and other loading parameters) the response can be either adaptive (mostly lamellar bone) or injury (mostly woven bone).
How do bones withstand tension and compression?
Bone is resistant to bending, twisting, compression and stretch. It is hard, because it is calcified, and the collagen fibres help the bone to resist tensile stresses. If you dissolve away the calcium salts of bone, then the bone becomes rubbery because of the collagen fibres which are left behind.
Why is the process of mechanotransduction so important?
Mechanotransduction, the process by which cells convert external mechanical forces into biochemical responses, is important in maintaining adult bone health and homeostasis. Application of mechanical loading has been shown to accelerate bone formation rates in animal studies (Fig. 14.1) [18–20].
What happens to stem cells during mechanotransduction?
For example, stem cells in the bone marrow may experience fluid flow–induced shear stress, tensile and compressive strains, and intramedullary pressure [28,35–37]. Mechanical loading activates multiple signaling pathways, resulting in osteogenic and antiresorptive responses.
What is the role of the cytoskeleton in mechanotransduction?
However, the precise role (s) of the cytoskeleton in mechanotransduction is (are) unclear: it could activate or splint the channel, shielding it from strain transmission through the lipid membrane. Under physiologic conditions, the mechanical interconnecting system is prestressed, (“tensegrity”) conferring mechanical balance and stability.
What are the functions of mechanotransduction in mammals?
Mechanotransduction, the conversion of mechanical forces into biological signals, plays critical roles in various physiological and pathophysiological processes in mammals, such as conscious sensing of touch, pain, and sound, as well as unconscious sensing of blood flow-associated shear stress, urine flow, and bladder distention.