What Is Thirst?

I can safely say there isn’t one single, healthy human being on this planet who hasn’t experienced thirst at some or other stage of their life. We know thirst as that dry, annoying and sometimes desperate feeling in our throats, mouths and bodies that alerts us to the fact that we need to drink something. That “something” is usually water – which is what quenches our thirst the best.

But, what makes us thirsty?

Science tells us thirst can be attributed to four major influencers:

Hypertonicity:

Cellular dehydration acts via an osmoreceptor mechanism in the hypothalamus.

Plain English – our cells in our body are shrivelling up from insufficient water intake. Our brains tell us we need to drink water.

Hypovolaemia:

Low volume is sensed via the low pressure baroreceptors in the great veins and right atrium.

Plain English – our hearts and veins pick up a drop in pressure caused by dehydration.

Hypotension:

The high pressure baroreceptors in carotid sinus & aorta provide the sensors for this input.

Plain English – Our hearts are already under pressure to pump oxygenated blood – and with “low blood pressure” they send a message to our brains telling us to increase our water intake.

Angiotensin II:

This is produced consequent to the release of renin by the kidney (eg in response to renal hypotension)

Plain English – when our kidneys come under fire, due to being under strain in filtering out toxins or simply not having sufficient water available to assist filtration, a hormone is secreted into our blood triggering the thirst mechanism.

Thirst Is Science In Action

Thirst is one of the most primitive and easily remedied functions our bodies are capable of inducing. Thirst isn’t a response to external stimuli, as sometimes hunger can be, but is rather a message from pretty much anywhere in our bodies which may be in need of water. It’s vital to remember, though, that when we sense thirst – we are already dehydrated, so try not to let it get to the point of being parched, but rather keep hydrated throughout the day to avoid feeling “not-so-great”.

Information sourced from anaestehsiamcq.com

Hangovers and Hydration: A Scientific Explanation

If you’re one of the lucky few people in this world who have never had to experience a hangover from a slightly excessive intake of alcohol the night before, then consider yourself exceptionally lucky.

But, I can almost promise you’ve sat quietly wondering to yourself why alcohol has such hard-hitting effects on us, and why we feel the way we do in the day(s) following a heavy night of consumption.
We have a scientific explanation behind your hangover – prepare to have your mind blown!

Water Density and Alcohol Density

It’s important to realise that a hangover is our body’s natural response – not to protect us – but a regulated, scientific and natural response to a liquid density.

See, Osmosis is happening around us, inside of us and outside of us every second of every day. A basic concept of what Osmosis is, in it’s most basic understanding, is the attempt of two bodies of water, separated by a porous membrane, to have equal parts of density on both sides of the membrane. It’s a lot more complicated than that, but for the purpose of ease-of-learning, we’ll be using that as our springboard for our hangover explanation.

See, water density is always going to be lower than alcohol density – for obvious reasons (i.e. – water is a universal solvent, so while your alcohol might be made up of 80% water, the remaining 20% comprising of additives and alcohol itself thus classes alcohol as much higher density).

So, back to our explanation: When you drink a beer, it reaches your stomach within a few minutes. Your stomach itself will now be the porous membrane, and the blood on the other side of your stomach now becomes the “liquid” which your body will try to bring to the same density as the alcohol you’ve just consumed.

So, how does your body get it right? Osmosis works on the principal that the liquid with the lowest density will move towards the liquid with the highest density; this case means that the water in your blood will try to move to the beer. Yes, the eater in your blood is literally sucked into your stomach to try even out the imbalance of liquid density in your stomach!

The more beer you drink, the more water is going to be leached from your blood in an attempt to satisfy your body’s natural need to get itself into a state of stasis (constant balance). The funniest part is, Osmosis never ends. It is in constant flux, moving higher and lower density liquids interchangeably.

Anyway – the more water that is leached from your blood, the more dehydrated you become. We find ourselves feeling more thirsty, urinating 1 litre when we KNOW we only drank a 330ml beer (makes sense now, doesn’t it?) and eventually, when the end of the drinking sessions looms – we are so dehydrated it’s actually quite dangerous – but our minds are in an altered state from the alcohol.

This also clearly explains why some experts have suggested drinking one glass of water for every can or glass of alcohol consumed; this prevents hangovers and might actually end up in you needing to use the restroom less!

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Image Credit: Virgin Pure