The human earlobe is composed of tough areolar and adipose connective tissues, lacking the firmness and elasticity of the rest of the pinna.
Since the earlobe does not contain cartilage it has a large blood supply and may help to warm the ears and maintain balance.
However earlobes are not generally considered to have any major biological function.The earlobe contains many nerve endings, and for some people is an erogenous zone.
Earlobes average about 2 cm long, and elongate slightly with age. Although the "free" vs. "attached" appearance of earlobes is often presented as an example of a simple "one gene - two alleles" Mendelian trait in humans, several studies suggest that the story is not that simple. A quick survey of your friends will reveal that earlobes do not all fall neatly into either the "free" or the "attached" categories; there is a continuous range from one extreme to the other, suggesting the influence of several genes.
Earlobes are normally smooth, but occasionally exhibit creases. Creased earlobes are sometimes associated with genetic disorders in children, including Beckwith-Wiedemann syndrome. In some early studies, earlobe creases were alleged to be associated with an increased risk of heart attack and coronary heart disease; however, more recent studies have concluded that since earlobes become more creased with age, and older people are more likely to experience heart disease than younger people, age may account for the findings linking heart attack to earlobe creases. The earlobe crease is also called Frank's Sign.
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