Physiological background to skin ageing.

Synopsis Ageing and ultimate death, when survival offers no reproductive advantages to the species, are essential to the evolutionary process. Yet the prolongation of youth has always been a human dream. The prevention of ageing in visible areas of skin is desirable not for physiological but for social reasons; the skin proclaims our sexuality and asserts our social image. Has the aspiration any hope of success? Ageing of the skin involves changes in the dermis, epidermis, pigment cells, hair follicles, sebaceous and sweat glands, and sense organs. Some of these changes appear intrinsic to the organs concerned; some are dependent on hormonal and other systemic mechanisms; some involve environmental factors such as radiation. If changes of the first type appear to be inevitable, those of the second may be modifiable, and those of the third may, to some extent, be preventable.