The head is of great importance in that it contains many different organs. The senses of vision, hearing, taste, smell and balance are located here; it contains the brain as a communication centre between ourselves and the surroundings and various parts of our body in relation to each other; it is also the site of the vital entrances for air and food. A less obvious, but still very important function of our head must also not be overlooked. The face is the major organ of expression, our ‘visiting card’. There are about thirty small muscles in the face connecting the skin to the facial bones. They enable us to vary our features in minute nuances of expression. Moving an eyebrow up or down by a few millimetres changes the whole mood of expression we convey to others. The facial muscles are activated by the facial nerve. If this nerve is damaged by a stroke or paralysed in the syndrome known as Bell’s palsy, the face, or half of it, loses its mobility and expression.
Facial appearance has a strong psychological effect on our lives. The face is a vehicle of moods and expressions, but the reverse could also be said to hold true. Features and appearance are sometimes considered to be synonymous with personality and character. In former times this apparent correlation was rigidly used in phrenology, a ‘science’ that judged people upon ‘face value’. For instance, closely knitted eyebrows were said to suggest criminality and two eyes of different colour were considered a sign of the devil. Nowadays these views are largely obsolete. But we still judge people by their appearance. In books people’s features are described to suggest a certain character. A receding chin, for example, commonly denotes a weak will, a square jaw stands for decisiveness, a high forehead for intelligence, and a mouth can be cruel, generous or mean. The importance of appearance can be judged by the many claims of love at first sight.
The ‘ideal’ look is dictated by fashion magazines, films and advertisements. A vast industry has sprung up to provide us with the resources to camouflage deviations from this ideal. These range from cosmetics to permanent plastic surgery. If we really think about it, it is astonishing that there are people earning their living by cutting our hair in a certain style, or advising us how to make up our face in order to obtain a certain effect.
The hair, which can be styled, dyed, given permanent waves, and the like, is, in evolutionary terms, a rudiment of animal fur. Its potential length, its colour, whether curly or not, is determined by genes. Hair growth on both the chin and upper lip and balding are governed by testosterone, the male sex hormone. Because in women levels of this hormone are low, its effect is best seen in men. Women who have a skin that is very sensitive to testosterone, however, may also show a male pattern of hair distribution and thinning of the hair on the skull. Pigment determines the colour of hair. This colouring matter originates from pigmentin the hair roots. Air bubbles in the hair cause its colour to become lighter as people age; they cause dark hair to become grey and light hair to become silvery white. Because the air pockets are caused by a disturbance of growth in the hair root, and never in the horny mass of the hair itself, it is impossible to turn grey overnight. The colour of the hair is often thought to influence someone’s personality. Redheads, for example, are considered to be temperamental and impulsive people, but this is far from being an established fact. However, it is true that red-haired people are more prone to develop anaemia.
The nose is the organ of smell, and warms and moistens inhaled air. In some cultures the nose is the organ used to express love and tenderness: instead of kissing, noses are rubbed. The nose determines expression to a greater extent than we think. Of all types of facial plastic surgery, operations on the nose are performed most frequently. Famous people such as Barbra Streisand and Michael Jackson have had their noses done.
A face can be completely disfigured, if something happens to the nose, as is all too evident from the faces of some boxers. Psychologically, the nose can determine the message that the face conveys: the nostrils can flare in fear or anger.
The mouth is the gateway to the digestive tract, and through it we can also inhale air. The sense of taste is located in the mouth. The lips, so often the subject of poetical descriptions, are actually sensing organs, detecting aspects of the surroundings and food. The mouth is a powerful erogenous zone. Oral needs like smoking or chewing gum are often thought to be replacements for the mothers’ breast. The lips are also capable of expression. They can be pursed, can pout, smile and be drawn when a person is tired or sad. Smiling, in body language, often conveys the message to another person that there is no reason to be afraid. The facial expressions of animals are similar to those of people. Animals may, however, consider someone laughing in their presence a threat, because it involves the baring of the teeth.
In human beings and beasts of prey the eyes are in a straight plane at the front of the head. This arrangement gives us binocular vision, essential for a sense of depth. This enables us to estimate distances, a feature that is very useful in hunting. Herbivores have their eyes on each side of the head, giving broader fields of vision, which is important in order to survey the surroundings for danger.
The eyes, as more than one poet has described them, are the windows of our soul. In fact, the expression of the eyes is caused more by the eyelids and the small muscles around the eye, than by the iris itself. The iris consists of pigmented connective tissue and muscles that dilate or constrict the pupil. Its colour is determined by the thickness of its overlaying tissue layer and the amount of pigment. If this layer is thin and the pigment scarce, the colour of the iris is blue. An increased amount of pigment gives greyish shades and greenish lines. Large amounts of pigment give the iris a brown colour.
The pupil is nothing but a hole to let light pass to the underlying structures of the eye. The pupil constricts in strong light, protecting the eye. It dilates in darkness, and also when a person is frightened or excited. In China jade sellers used this phenomenon to discover if potential buyers were really interested. They looked at the buyers pupils, and if they were dilated in excitement, they would put up their prices. To prevent this, buyers began to wear sunglasses. Many people wear sunglasses, not for protection from the sun, but as a means of hiding their emotions.
Some people even go so far as to buy reflector lenses, which conceal the eyes completely and make communication rather difficult.
The neck contains thevessels that transport between the heart and the brain, and the vital passages for food and air. Its flexibility allows us the freedom to scan the surroundings without moving the rest of our body and is essential for stereoscopic vision. On the other hand because we do not depend on our ears, nose and teeth to survive, it is in this sense less important to us than it is to animals. The neck and its glands are susceptible to a number of disorders. By far the most common of these is mumps, or parotitis. It is an infectious disease carried by droplets released into the air when someone who is infected coughs or sneezes. It generally affects children and most cases are mild. Symptoms include swelling of the parotid glands on one or both sides of the face, pain in the jaw muscles, fever and sometimes vomiting. A person who has had mumps as a child rarely succumbs to the virus when an adult although re-infection is possible in some cases. Should an adult get the disease symptoms can be much more serious and about one in four men will develop inflammation of the testicles (orchitis) which may lead to sterilty.