A close up of an eye showing the capillaries. The definition of a capillary is a small blood vessel that is part of the network of the small arteries and small veins, or an extremely thin tube through which nothing thicker than a human hair can pass.
Phospholipid bilayer. Definition. noun. The two layers of phospholipids arranged in such a way that their hydrophobic tails are projecting inwards while their polar head groups are projecting on the outside surfaces. Supplement. This arrangement of phospholipids in bilayer is used to describe the cell membranes of many animal and plant cells. The two layers of phospholipids are arranged in a way that their hydrophobic tails are projecting to the interior whereas their hydrophilic heads are projecting the exterior.
Phospholipids are a class of lipids that are a major component of all cell membranes. They can form lipid bilayers because of their amphiphilic characteristic. The structure of the phospholipid molecule generally consists of two hydrophobic fatty acid tails and a hydrophilic head consisting of a phosphate group.The two components are joined together by a glycerol molecule. The phosphate groups can be modified with simple organic molecules such as choline.hey can form lipid bilayers because of their amphiphilic characteristic. The structure of the phospholipid molecule generally consists of two hydrophobic fatty acid tails and a hydrophilic head consisting of a phosphate group. The two components are joined together by a glycerol molecule.