HEAD

In a newborn baby, the head accounts for one-quarter of the total body length; by adulthood, the proportion has reduced to one-eighth. Contained in the head are the body's main sense organs: eyes, ears, olfactory nerves that detect smells and the taste buds of the tounge. Signals from these organs pass to the body's great coordination centre: the brain, housed in the protective, bony dome of the skull. Hair on the head insulates against heat loss, and adult males also grow thick faical hair. The face has three important openings: two nostrils through which air passes, and the mouth, which takes in nourishment and helps form speech. Although all heads are basically similar, differences in the size, shape and colour of features produce an infinite variety of appearance.

BODY FEATURES

Although there is enormous variation between the external appearances of humans, all bodies contain the same basic features. The outward form of the human body depends on the size of the skeleton, the shape of the muscles, the thickness of the fat layer beneath the skin, the elasticity or sagginess of the skin, and the person's age and sex.
Males tend to be tallen than females, with broader shoulders, more body hair, and different pattern of fat deposits under the skin; the female body tends to be less mascular and has a shallower and wider pelvis to allow for childbirth.