Ear Wax – Ceruminous glands: microbes, mammary glands and medieval manuscripts
Dr Adam Taor; 24/1/09; ;
What are they and what do they do? Ceruminous glands live in the greenhouse of your body — the damp, dark, warm caverns that are your ear holes (external auditory canals). In the canals’ walls, they make cerumen, aka earwax. The cer in their name comes from the Latin for wax, cera. Strangely, pain, anxiety and fear stimulate them to make wax. Chewing also makes them pump out cerumen.
The Australian; No Internet Text
– What’s earwax for?
Like greenhouses, your ear holes are great for growing things, for example bacteria and fungi. Cerumen protects you by keeping your ear canal dry and lining the skin, stopping microbes invading. It may also directly kill bacteria. People who don’t make enough earwax are vulnerable to ear canal infections.
– Why are their secretions gooey and bitter?
To catch things bigger than bacteria. Cerumen is great at trapping dirt, dust and hairs, which join the flow of debris in the ear canal that moves from the eardrum outwards. Jaw movements also drive earwax out the canal. Cerumen may be bitter to deter insects from making a home in our ear holes.
– How can they tell races apart?
Not all earwax is the same. Asian people have dry, flaky, light grey earwax, called “rice bran” wax. Caucasians and people of African or Latin descent have stickier, smellier, golden brown cerumen.
– How are they connected to breasts?
These glands resemble tissue in mammary glands — breasts — and the different cerumen types are linked to breast cancer risk. People with dry cerumen produce fewer breast secretions and have a reduced risk of breast cancer.
– How do they make books beautiful?
Ornately painted and gilded (illuminated) medieval manuscripts have earwax to thank for their beauty. The goo from ceruminous glands was used as a binding agent for pigments to decorate the manuscripts.