What is skin anisotropy?
The skin’s reduced scattering coefficient mu(s)’ varies by up to a factor of two between different directions of propagation at the same position. This anisotropy is believed to be caused by the preferential orientation of collagen fibres in the dermis, as described by Langer’s skin tension lines.
Is skin isotropic or anisotropic?
Skin is found to be highly anisotropic and viscoelastic, with a range of Young’s Modulus between 5 kPa and 140 MPa.
What is viscoelasticity of skin?
Skin viscoelasticity (SVE) incorporates the water content of the skin and adds the principle of viscosity, the internal resistance to flow when a shearing force or stress is applied to a fluid.
Why is anisotropy important?
Anisotropy might be important for extrasynaptic transmission by channeling the flux of substances in a preferential direction, and its loss may severely disrupt extrasynaptic communication in the CNS, which has been suggested to play an important role in memory formation.
What is the density of human skin?
1.02 g/cm2
Calculations assumed a skin mass density of 1.02 g/cm2 and a Poisson’s ratio of 0.5.
What are the properties of the skin?
Skin has three layers:
- The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone.
- The dermis, beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands.
- The deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue.
What does a Cutometer do?
The Cutometer® is intended to measure viscoelastic properties (elasticity, firmness, tonicity and suppleness) of the skin. The principle is based on a mechanical deformation of the skin via the suction method.
What makes tissue viscoelastic?
Biological tissues are modeled as viscoelastic materials due to the manifestation of hysteresis in their stress relaxation behavior [21, 22]. The word viscoelastic is a combination of viscous fluidity and elastic solidity, and thus, biological materials under stress and strain exhibit both viscous and elastic behavior.
What causes anisotropy?
Anisotropy is caused by asymmetry and specific orientation of the molecules themselves. This explains the natural anisotropy of certain liquids, especially liquid crystals. For instance, plywood or compressed wood may have piezoelectric properties like crystals because of their laminar structure.
What is anisotropy in biology?
Growth anisotropy describes the condition when growth rates are not equal in all directions. In contrast, when growth rates are the same rate in all directions, growth is isotropic. Anisotropy is a hallmark of plant growth. Almost without exception, cells grow faster in one direction than in another.