Lose weight: Creating a calorie deficit that results in weight loss is hard work. Most recommendations say that to lose weight, you must exercise for at least an hour a day, five times a week. The type of exercise matters, too.
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia. hair shaft. the nongrowing portion of a hair that protrudes from the skin, that is, from the follicle. hair shaft. The keratinized portion of a hair that extends from a hair follicle beyond the surface of the epidermis.
The hair shaft and root are made of 3 distinct layers of cells: the cuticle, cortex, and medulla. The cuticle is the outermost layer made of keratinocytes. The keratinocytes of the cuticle are stacked on top of each other like shingles so that the outer tip of each cell points away from the body.