Hair

And as the hair is stretched, its structure changes in a particular way. | Hair consists of two main parts - the cortex, which is made up of parallel fibrils, and the matrix, which has an amorphous (random) structure. | The combination of these two components, Yu explained, is what gives hair the ability to withstand high stress and strain. | This structural change allows hair to handle a large amount of deformation without breaking. | The matrix is sensitive to the speed at which hair is deformed, while the cortex is not.