Hiding under the shoulder joint you’ll find me warm and snug. I’m occasionally hairy and smelly, but always vulnerable to tickling. My medical name is axilla, but you can call me Amy’s armpit.
Despite what you may think, there is much complex anatomy in us. We have veins, arteries, nerves, fat, alveolar tissue and lymph nodes (small lumps of tissue, part of the lymphatic system that helps to fight infection). On our skin surface we have loads of sweat glands, but here are two types: the eccrine and apocrine glands. The eccrine glands are useful when Amy gets hot, they cool her down by secreting salt and water, but don’t cause the smelly odour known as BO (body odour). The apocrine glands are the culprits; they secrete proteins and fats along with sweat, which react with the bacteria found on my skin, to create a foul odour. This natural odour was thought to act to repel other animals who may have wanted to eat humans, like Amy, thousands of years ago. But the natural human smell is also considered unpleasant to other humans and could deter a potential boyfriend.
It is now considered a social taboo to smell, so products like deodorants and anti-perspirants have become very popular. Deodorants don’t stop the secretion from the apocrine glands, but change my armpit environment to make it either too salty or acidic for bacteria to survive. Anti-perspirants work by blocking the sweat glands, using aluminium or zirconilum, to prevent sweating. They often also contain an ingredient to kill the bacteria as a failsafe.
When Amy was 13 years old she started to go through puberty and I started to get hairy! Both girls and boys grow armpit hair during their teenage years, but boys often chose not to remove theirs whilst girls do. The evolutionary significance of underarm hair is still under debate, but is thought to help move sweat and moisture away from the skin surface to aid ventilation. Amy has chosen to shave me, as all of her friends do, but this can lead to ingrowing hairs, is often time-consuming and reinforces the cultural standards against hair on women. Some men also chose to remove their underarm hair for aesthetic reasons (bodybuilders), to reduce friction (swimmers) but, in the culture of Islam, both men and women are required to remove their body hair.
Some women however chose to go against the social norm and let their underarm hair grow. The feminist movement, the punk rock movement and hippie culture, all saw women defying the norm and allowing the hair on us to grow. So why not let your armpit free this month and support Armpits4August, Amy has already started with me.