ForensicsNotes-RaleighCharterHighSchool：取证笔记-罗利特许高中.docVIP

Forensics Notes Fingerprint Analysis Skin The skin is made up of three distinct layers.???? The top layer is called the epidermis. (The word epidermis, and the name of the other main skin layer, the dermis, both come from the name used by the ancient Greeks for the skin, derma. From this we also get the word dermatologist, meaning a doctor who specialises in skin problems.)????The epidermis is translucent. That is, it allows light to pass partially through it, rather as frosted glass does. The epidermis does not contain any blood vessels but gets its oxygen and nutrients from the deeper layers of the skin.????At the bottom of the epidermis is a very thin membrane, called the basement membrane, which attaches the epidermis firmly, though not rigidly, to the layer below.????The second layer lies deeper and is called the dermis. It contains blood vessels, nerves, hair roots and sweat glands.????Below the dermis lies a layer of fat, the subcutaneous fat. The depth of this layer differs from one person to another. It contains larger blood vessels and nerves, and is made up of clumps of fat-filled cells called adipose cells. ????The subcutaneous fat lies on the muscles and bones, to which the whole skin structure is attached by connective tissues. The attachment is quite loose, so the skin can move fairly freely. If the subcutaneous tissues fill up with too much fat the areas of attachment become more obvious and the skin cannot move as easily -this is what gives rise to the notorious cellulite. Fingerprint Formation The uniqueness of fingerprints (epidermal ridges) has been recognized for over two thousand years. They have been studied scientifically for more than two hundred years. Yet, in spite of the accumulation of a wealth of empirical and experimental knowledge, no widely accepted explanation for the development of epidermal ridges on fingers, palms and soles has yet emerged. Informed by an extensive literature study we suggest that fingerprint patterns