An ear is like an iceberg: much of it is out of sight. The only visible part is the atrium, a shell-shaped structure made of flexible cartilage and covered with skin.
Its main function is to act like a trumpet, filtering and channeling sound waves into the middle ear and then into the inner ear, where they become our sense of hearing.
A medical ear exam usually involves an inspection of the canal using an instrument called an otoscope. This is usually done to investigate more common ear conditions: an infection or wax blockage.
But the pinna, also known as the outer ear, can also tell stories about your health, family traits, and even whether you play high-contact sports.
The shape of each ear is as unique as a fingerprint and each part has a name.
The fleshy, hanging part at the bottom is the earlobe. The folded top, which curves along the edge of the ear, is the helix (named for its shape) and the two prominent areas next to the canal are the tragus and antitragus.
The word “tragus” is derived from Greek and means goat. This is because the tragus is usually covered with hairs, giving it an appearance similar to the chin of a goat.
See for yourself: you may not have realized the hairs were there.
The shape and the genetics behind it
The earlobes feel different from the rest of the ear. They lack cartilage, so they feel soft and squishy, rather than firm and flexible.
But the appearance of your earlobe can vary depending on your genes: they are free (with a hanging piece) or attached (directly to the head).
Initially, it was believed that the allele (a form of gene) that codes for free lobes is dominant, meaning that you only have to have one copy of the gene, either from your mother or your father. The attached lobes were understood to come from recessive alleles, meaning they had to be inherited from both parents. That made free lobes more common.
But now we know that it is not that simple. There is a spectrum between free and attached lobes, encoded by many different genes.
Take a look at your own lobes, those of the people you live with, and those of some famous people. They vary in size and shape. And we have everything from Charlize Theron’s free lobes to Gwyneth Paltrow’s attached lobes.
Additionally, wearing heavy earrings can elongate your lobes and alter your appearance as well.
The earlobes are rich in sensory nerve fibers, giving them the reputation of being an erogenous zone, sensitive to touch, breathing and biting.
Diseases: gout and tophi
Gout is increasing. It’s not just a disease of the Georgian aristocracy, it’s a systemic condition that can affect the joints, heart, kidneys and even the ears.
It is caused by high levels of uric acid in the bloodstream, which turns into crystals. If these accumulate in the joints, they can inflame and erode them, causing painful swelling.
High uric acid is also associated with higher levels of “bad” cholesterol and cardiovascular diseases, such as high blood pressure and stroke.
Occasionally, uric acid crystals may develop under the skin. They can appear as small lumps called tophi, which often form in the tissue around the joints, but also in the ears.
Tophi are firm and look like pebbles, hence their name (the singular tophi is Latin for stone). If tophi break through the skin or are surgically removed, they usually look chalky.
Tophi usually form over long periods of time and are only associated with gout.
Sports and cauliflower ear
Protruding from the sides of our heads, in varying degrees of protrusion, our ears are vulnerable to damage. Earrings can easily break holes if they get caught. Ears are often traumatized during fights and sports.
Boxer Mike Tyson even bit off a piece of his opponent Evander Holyfield’s ear during a fight, for example.
One of the most unmistakable traumatic conditions is cauliflower ear, also known as wrestler’s ear or boxer’s ear. Its medical name is subperichondrial hematoma, a technical term to describe the collection of blood around the cartilage of the ear as a result of mechanical damage, such as a direct blow to the ear.
The problem is more serious than it seems. Damage to the vessels, and built-up blood pressure, can deprive the cartilage of oxygen, causing it to degenerate. The body’s response is to produce a lumpy mass of connective tissue – and a “cauliflower” ear is formed.
Cauliflower ears can be prevented by avoiding sports most associated with the condition, such as rugby, wrestling and martial arts.
For those who love contact sports, a protective cap or scrum cap can help protect your ears.
If a bruise occurs, it is important to aspirate it with a needle to protect the cartilage from damage.
The external and visible parts of our ears, therefore, are more than just decorative. Its functions range from the transmission of sound waves to sexual arousal. And changes in appearance can reflect the sports we like to play to the style of jewelry we prefer.
*Dan Baumgardt is a senior lecturer in the School of Physiology, Pharmacology and Neuroscience at the University of Bristol.
*This article was published on The Conversation and reproduced here under the creative commons license. click here to read the original version.
Keep reading:
* Do you feel vertigo? It can be caused by a hearing defect
* Do you feel like you listen little? It could be otosclerosis
* What is hearing loss and how does it affect the auditory system?
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