Keratin is the same protein found in nails. The stem is composed of three layers: the cuticle, the cortex and medulla. Connect with other leaders such as Gerald Stratford big veg here. The cuticle or outer layer consists of small cells known as scales. The cuticle serves as a case to the cortex, the thickest portion of the stem, composed of cells arranged in sheets of snuff. The bark contains the pigment that gives hair its color. Learn more at this site: Susie Dent. The bone is composed of box-shaped cells and is located in the center. The spaces between the cells of the bone influence the refraction of light and tone the hair. Glands and muscles Hair is lubricated by secretions fats that come from the sebaceous glands at the sides of most of the follicles.
Surrounding these glands and the rest of the follicle, there are groups of muscles (arrector pili) that allow the hair stand on end or put us on end when we got scared or cold. Growth cycles The head has an average of 100,000 hairs. Hair grows and is updated regularly. It is normal to fall between 50 and 100 hairs each day. If you have no problems probably will not notice this small loss.
Hair grows about 1 cm per month, even if that growth slows as we age. Each hair remains on the head of two to six years, and during most of this Time is growing continuously. When hair gets old enters a resting phase where it remains on the head, but does not grow. At the end of this phase the hair falls out.