Hair is a biomaterial that covers almost all parts of the human body. It plays a number of roles, ranging from providing offensive protection to camouflaging and thermal regulation. There are many different kinds of hair, and they all have different functions. Some are fine and silky, while others are thick and coily.
Hair is made up of three layers: a cuticle, a medulla and a shaft. The medulla is made up of a soft substance that provides a barrier against chemical and physical insults. Keratin is the main component of the cuticle and medulla, and it is responsible for the waterproofing of the hair. In addition, the keratin also acts as a protein filament. This structure gives the hair resistance, elasticity and flexibility.
The follicle is an organ under the skin that contains cells that produce new hair. It is a tube-like structure made of layers of cells and oil glands. A small vessel is located in the follicle that ensures a blood supply.
The follicle is similar to the sock. A follicle’s shape is round or bulb-like. Inside the follicle, nerve fibers let us feel the hair. It is surrounded by melanocytes, which produce pigments and inject them into developing hair shafts. As the follicle matures, it goes through rest, shedding, and regrowth phases. These cycles vary depending on the person’s age, nutritional status, and location of the hair.
Each individual’s hair can be defined by its curl pattern. The basic pattern is present in the DNA, but it can be manipulated by hormones and other chemicals. For example, people with curlier hair may need to moisturise more often. On the other hand, those with straight, coarse hair will not need to apply moisturizer as often.
During development, the follicle develops a layer of cells called the secondary epithelium. It is composed of macrofibrils and other specialized cells. After a few weeks, the follicle will have formed a tube-like structure that holds the hair.
The cuticle is a thin, protective outer layer that is made up of scale-like cells. It is adhered to the cortex proximally and has barrier functions against physical and chemical insults. During a growth cycle, the hair’s base is determined by the size of the base cells.
Hair is classified into four types: type 1, type 2, type 3, and type 4. Hair can be long, short, straight, or curly. Type 3 is curly, while type 2 and type 1 are wavy.
Most mammals, including humans, have hair. The earliest known animals to have hair were synapsids. Cynodonts and hedgehogs have been found to have modified hairs. Those with loose curls and coils are commonly considered to be type 3.
Hair has two distinct structures: the follicle and the shaft. The follicle is a structure under the skin, while the hair is a protein filament that extends over the skin surface. It serves as a source of heat insulation, protection against UV radiation, and as an apocrine sweat gland.