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Biomechanics

Biomechanics in motion

About[]

Biomechanics is the study of the structure and function of biological systems by means of the methods of the laws of mechanics and physics applied to the human body. he study of biomechanics can take place on a range of scales and levels, from the molecular level of cell signaling to the study of entire organisms. Understanding how organisms move is an important aspect of this field, as is the understanding of mechanical systems in the body such as the circulatory system and the digestive tract. While people may not think of living organisms as machines, in many ways, they actually perform a lot like machines, and the concepts used in basic mechanics can also be applied to the body.

One field of interest in biomechanics is the study of injuries.

Bio-fluids[]

Under certain mathematical circumstances, blood flow and circulation can be modeled by the Navier–Stokes equations. In vivo whole blood is assumed to be an incompressible Newtonian fluid, however, this assumption fails when considering forward flow within arterioles. In microscopic scale, the effects of individual red blood cells become significant, and whole blood can no longer be modeled as a continuum. When the diameter of the blood vessel is slightly larger than the diameter of the red blood cell the Fahraeus–Lindquist effect occurs and there is a decrease in wall shear stress. However, as the diameter of the blood vessel decreases further, the red blood cells have to squeeze through the vessel and often can only pass in single file. In this case, the inverse Fahraeus–Lindquist effect occurs and the wall shear stress increases.[1]

Under certain mathematical circumstances, blood flow can be modeled by the Navier–Stokes equations. In vivo whole blood is assumed to be an incompressible Newtonian fluid, however, this assumption fails when considering forward flow within arterioles. In microscopic scale, the effects of individual red blood cells become significant, and whole blood can no longer be modeled as a continuum. When the diameter of the blood vessel is slightly larger than the diameter of the red blood cell the Fahraeus–Lindquist effect occurs and there is a decrease in wall shear stress. However, as the diameter of the blood vessel decreases further, the red blood cells have to squeeze through the vessel and often can only pass in single file. In this case, the inverse Fahraeus–Lindquist effect occurs and the wall shear stress increases.[2]

Cells[]

Cell biomechanics refers to the mechanical function of cells in terms of biology. Biomechanics is an interdisciplinary area of ongoing research that focuses on the mechanistic behaviors of cells and the biological influences associated with those behaviors. The study of cell biomechanics draws on the disciplines of mechanical engineering, biochemistry, and anatomy and physiology.

Fundamental research in cell biomechanics involves the structure, organization and other primarily physical properties of cell function. The purpose of biomechanics is to further the understanding of normal and disease physiology on a cellular level. Scientists who specialize in cell biomechanics have developed tools using microfabrication and innovative nanoscience and bioengineering processes. These tools allow scientists to collect and examine cell and protein samples on a molecular level. This approach focuses on the small parts of a larger, functioning system, which is the essence of cell biomechanics.

Cellular biomechanics also has been referred to as biomechanics or mechanobiology; all are terms that reflect the interdisciplinary nature of this specialization. By studying the mechanical properties of cells involved with diseases such as cardiovascular disease and cancer, researchers may be able to find treatments and cures for otherwise fatal diseases. These properties include biophysical forces, adhesive properties and spatial organization. For example, the fluid components of a cell are associated with membrane stress, permeability and gene expression. Scientists have been using biomechanics to identify a way to study cellular behavior on a larger scale, in terms of tissues and organs affected by disease.

Cells are the building blocks of life, and a chain of biochemical reactions is vital for normal, biological processes to function properly. These reactions often occur within the cell wall under highly specific conditions. When the cellular environment or cell biomechanics become altered in some way, the result on healthy cells can cause hypertension, strokes and many other medical problems. All normal, body functions — such as healing, swelling and hormone release — involve the role of cells. The need to understand how these things happen, not just why or when they happen, is what cell biomechanics aims to achieve.

Biomechanical measurements of cells have been obtained through a wide variety of methodologies, ranging from fluid dynamics to signal transduction. Biomechanical analysis alone has seen a wide range of advancements and uses, including human kinetics and athletic training. The basic approach remains the same; biomechanical analysis captures the physical measurements associated with movement and associates or attributes the data to biological processes. [3]


Tissue[]

Tissue biomechanics is the study of how different parts of the human body, such as bone, tendons, and muscle, react to external forces. Researchers have analyzed the mechanical properties of these tissues, which ordinarily can withstand a certain level of force before being damaged. Average tolerance levels have been estimated for each, which have often aided in many different studies. Motion, force, and acceleration of healthy tissue can hit specific levels and cause either sudden damage or degradation that can occur over time. Tissue biomechanics is often used to determine how an injury took place or to assess the viability of prosthetic devices or medical implants.

Forces that cause stress on tissue, or make it change shape, may actually be beneficial, at times. Normal bone development often depends on pressures exerted by regular motion and even gravity. Too little pressure, such as during space travel or prolonged bed rest, can lead to bone abnormalities or weakening. Other tissues such as tendons and ligaments can weaken as well, while repeated stressful motions can damage these structures. The mechanical causes of damage, based on knowledge of anatomy and physiology, are typically studied in tissue biomechanics.[4]


References[]

  1. Wikipedia. Biomechanics. December 24 2012. | Fluid Biomechanics.
  2. Wikipedia. Biomechanics. December 24 2012. | Fluid Biomechanics.
  3. Wise Geeks. Cell Biomechanics. | Cell Biomechanics.
  4. Wise Geeks. Tissue Biomechanics. | Tissue Biomechanics.


Links[]

http://en.wikipedia.org/wiki/Biomechanics#Bio-fluid_mechanics


Video[]

Bone_biomechanics_A_Big_Picture_film_by_the_Welcome_Trust

Bone biomechanics A Big Picture film by the Welcome Trust

A Big Picture film by the Welcome Trust

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