adhesion

Examples of adhesion in the following topics:

• Adhesions

  • If this is allowed to happen, tissue repair cells such as macrophages, fibroblasts and blood vessel cells, penetrate into the fibrinous adhesion, and lay down collagen and other matrix substances to form a permanent fibrous adhesion.
  • In the case of adhesive capsulitis of the shoulder (also known as frozen shoulder), adhesions grow between the shoulder joint surfaces, restricting motion.
  • Abdominal adhesions (or intra-abdominal adhesions) are most commonly caused by abdominal surgical procedures but may also be caused by pelvic inflammatory disease or endometriosis.
  • Small bowel obstruction (SBO) is another significant consequence of post-surgical adhesions.
  • The majority of fibrinous adhesions will disappear in due course.

• Transdermal Drug Administration

  • Transdermal drug delivery can be acheived by a medicated adhesive patch to deliver a dose of drug through the skin and into the bloodstream.
  • Single-layer, drug-in-adhesive: The adhesive layer of this system also contains the drug.
  • Multi-layer, drug-in-adhesive: The multi-layer, drug-in adhesive patch is similar to the single-layer system in that both adhesive layers are also responsible for releasing the drug.
  • The adhesive layer in this patch surrounds the drug layer, thereby partially overlaying it.
  • Vapor patch: In this type of patch, the adhesive layer not only serves to adhere the various layers together, but also to release vapor.

• Desmosomes

  • The cell adhesion proteins of the desmosome - desmoglein and desmocollin - are members of the cadherin family of cell adhesion molecules.
  • The symptoms of the diseases are caused by the subsequent disruption to the desmosome-keratin filament complex leading to a breakdown in cell adhesion in the skin.
  • A desmosome, also known as macula adherens (Latin: adhering spot), is a cell structure specialized for cell-to-cell adhesion in animal cells.
  • A type of junctional complex, they are localized spot-like adhesions randomly arranged on the lateral sides of plasma membranes.

• Water’s Cohesive and Adhesive Properties

  • Cohesion allows substances to withstand rupture when placed under stress while adhesion is the attraction between water and other molecules.
  • This type of adhesion is called capillary action .
  • Why are cohesive and adhesive forces important for life?
  • Cohesive and adhesive forces are important for the transport of water from the roots to the leaves in plants.
  • Water's cohesive and adhesive properties allow this water strider (Gerris sp.) to stay afloat.

• Hemidesmosomes

  • Rather than using desmogleins, hemidesmosomes use desmopenetrin cell adhesion proteins.
  • Together with the anchoring fibrils and anchoring filaments, these are collectively termed the HD-stable adhesion complex or HD-anchoring filament complex.
  • An example configuration of a hemidesmosome might consist of cytosolic keratin, non-covalently bonded to a cytosolic plectin plaque, which is bonded to a single-pass transmembrane adhesion molecule such as the α6β4 integrin.
  • The integrin might then attach to one of many multi-adhesive proteins such as laminin, resident within the extracellular matrix, thereby forming one of many potential adhesions between cell and matrix.

• Adherens Junctions

  • Zonula means small zone or belt-like, and adherens refers to adhesion (sticking together). 
  • You can call it an adhesion belt as a result. 
  • These are transmembrane adhesion proteins, whose main portions are located in the extracellular space.

• Surface Tension

  • The contact angle is measured in the liquid and depends on the relative strength of cohesive forces in the liquid and adhesive forces between the liquid and interface materials.
  • If liquid molecules are strongly attracted to the molecules of the solid surface (adhesive forces > cohesive forces), the drop will tend to spread out and the contact angle will be close to zero degrees .
  • If the cohesive forces are greater than the adhesive forces, the resulting contact angles will be large and will form a more circular drop .
  • When a water droplet forms on a leaf, the cohesive forces between the water molecules are greater than the adhesive forces between the water and leaf surface.

• Capillary Action

  • On the other hand, when intermolecular forces occur between different types of molecules (especially when they are part of different phases of matter), they are referred to as adhesive forces, or resulting in adhesion.
  • It occurs when the intermolecular attractive forces between the liquid and the solid surrounding surfaces (adhesive forces) are stronger than the cohesive forces within the liquid.
  • If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container act together to lift the liquid.
  • A convex meniscus occurs when the molecules have a stronger attraction to each other (cohesion) than to the material of the container (adhesion), causing the surface of the liquid to cave downward.
  • The curvature of the surface at the top of a column of fluid in a narrow tube is caused by the relative strength of the forces responsible for the surface tension of the fluid (cohesive forces) and the adhesive forces to the walls of the container.

• Surface Tension and Capillary Action

  • Attractive forces between molecules of different types are called adhesive forces.
  • In this section we examine effects of cohesive and adhesive forces in liquids.
  • If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and the container act to lift the liquid.

• Adherence

  • Adhesins are cell-surface components or appendages of bacteria that facilitate bacterial adhesion to other cells or to inanimate surfaces.
  • Adhesins are cell-surface components or appendages of bacteria that facilitate bacterial adhesion or adherence to other cells or to inanimate surfaces.