What’s in my tears? | Day 196

These past two days have been an emotional rollercoaster. Today my partner and I adopted a cat, after having talked about it for almost two years. She came from the NSW Cat Protection Society shelter, and we’ve finally brought her home after two weeks of waiting for all the health checks to complete. She’s my first pet ever, and this is supposed to be one of the happiest days of my life. In a way, it really is – I have my own cat.

However, this is also one of the saddest days. Last night I received news that my grandpa has died. He was 84 years old, and frail, and he had a major stroke on Monday, and this was coming. And yet the moment I found out, it washed over me like a wave of shock and disbelief, and before I knew it I found myself crying harder than I can remember. Because I’ll never see him again, and it just hurts so damn much. He was a wonderful man, and a wonderful grandfather, and I have only fond memories of him. Today the pain and crying is already slowly being replaced by a sort of numbness, yet I know I will shed more tears as I gradually go through the grieving process, exacerbated by the fact that I am over 15,000 kilometres away from my family at this time.

But I have to keep writing. So today’s story will be about the science of tears.

The fluid known as tears is produced by the lacrimal glands located in the outer portion of each eye orbit, and connected to the surface of the eye with an excretory duct known as the tear duct. These glands are also connected to the cavity of the nose via a special duct that runs from the lacrimal sac, in which the tears drain from the eye to accumulate. Hence, when you cry, the sac overflows and your nose gets runny as well. All together the tear production and secretion system is known as the lacrimal apparatus, and many mammals possess one, too.

The main function of this tear production system is to lubricate and clean the surface of the eye, maintaining a healthy moisture layer known as the tear film. In order to do so, the lacrimal glands generate two types of tears.

Basal tears are generated constantly – we release somewhere around a gram of these over every 24 hours. They are a salty water suspension of different fats, as well as a few antibodies and enzymes that can help deal with microbes.

Reflex tears happen when the eye or its environment needs to be cleared out due to an irritation – including allergens and things like tear gas – or even a foreign object, such as a grain of sand. The chemical content of these tears is similar to basal ones, but they are thought to contain more microbe-fighting substances.

Which leaves the third type of tears, known as emotional  or psychic tears. These are brought on by emotional stress or pleasure, or physical pain. Only humans weep with emotion, and there are various theories on why that might be the case. It is also thought that emotional tears contain more protein than other types of tears, although this is hardly settled science. I have seen hypotheses that emotional tears help get rid of a hormonal build-up in the body, but I have no reference for that one.

Whatever the reason for emotional crying, it is definitely cathartic, and somewhat soothing once you’re done. For now, I don’t know when I’ll be done crying, but it’s not today.

Although Audrey has been doing a good job of cheering me up.

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