What Is Thirst?

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

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!

Share you thoughts below!

 

Image Credit: Virgin Pure

Does Hot Water Freeze Faster Than Cold Water?

Does Hot Water Freeze Faster Than Cold Water?

Have you ever heard – or been advised- to make ice cubes with hot water instead of cold water? Some people say it’s because hot water will produce crystal-clear ice-cubes (as opposed to white-ish cubes when made with cold water) – or perhaps because the ice cubes would freeze faster if they were to be made with hot water?

“Hot water seems to freeze faster than cold water, known as the Mpemba effect. The effect was named after the Tanzanian student who in 1963 noticed that hot ice cream mix freezes faster than a cold one.”

An article, published by iflscience..com, theorises that the reasoning behind this is that it could be due to “…faster evaporation of hot water, therefore reducing the volume left to freeze; formation of a frost layer on cold water, insulating it; and different concentrations of solutes such as carbon dioxide, which is driven off when the water is heated.”

New developments, however, point us in the direction that “it is the chemical bonds that hold water together that provide the effect. Each water molecule is composed of one oxygen atom bonded covalently to two hydrogen molecules. These bonds involve atoms sharing electrons and are well understood. The separate water molecules are also bound together by weaker forces generated by hydrogen bonds. These forces occur when a hydrogen atom from one molecule of water sits close to an oxygen atom from another.”

“The stretching in the hydrogen bonds allows the covalent bonds to relax and shrink somewhat, which causes them to give up their energy. The process of covalent bonds giving up their energy is essentially the same as cooling, and so warm water should in theory cool faster than cold. The team’s calculations suggest that the magnitude of the covalent bond relaxation accounts for the experimental differences in the time it takes for hot and cold water to freeze.”

In plain English – it’s a scientific process that actually allows hot water to cool faster than cold water. So, next time you’re in a pinch to make some ice cubes for your Saturday afternoon party – try using some hot water( the purer, the better) to get the job done in almost half the time.

Why Does My Skin Go Wrinkly When I Bath Or Shower Too Long?

Why Does My Skin Go Wrinkly When I Bath Or Shower Too Long?

As I sit typing this, I’m reminded of a time when, as a kid, I’d sit in the bath far too long – and then see my fingertips all wrinkled up and freak out. We’d play games and tease that we were getting old, and show our parents proudly how we had “become prunes”.

As an adult, a lot of that wonderment is gone – now I just want to know why exactly that even happens?

Well, there’s two theories.

As humans, we’re bound to have our bodies adapt to changing environments – and this is no different. Imagine a car tyre – it has grooves on it so that is has the best possible traction to the tar road as possible. A smooth tyre means less grip – which is dangerous.

So, our bodies react similarly when we’re submerged in water for too long. The skin becomes taught and creates large ridges – in an effort to provide our bodies with a grip sturdy enough to keep us safe while we are submerged.

Another school of through is that it’s osmosis. The way osmosis works is that through a semi-permeable membrane (i.e. – our skin) – two bodies of water of different densities will try to equalise their density – by the higher density liquid attempting to move toward the lower density liquid.

Our blood is a higher density than that of our bath water – so by laying in a bath for too long – the osmosis cycle tries to instate itself.

So, next time your kid comes running to you, boasting he is wrinkly and “pruned” – teach them some science behind why they aged mysteriously in the bathtub.

 

Image Credit: Pitara Kids Network 

What Is In A Glass Of Tap Water?

What Is In A Glass Of Tap Water?

An article originally published on Popular Science allows users to visually interact with – and have their eyes opened to what exactly is in their glass of tap water.

 

Popular Science What Is In A Glass of Water

 

 

 

Chlorine In Tap Water

Chlorine is added as a disinfectant.

Pesticides

Insecticides and herbicides can wash into rivers and lakes and seep into groundwater.

Fluoride

As rocks erode, they naturally release fluoride into soil, air, and most water sources. Because it can prevent tooth decay by rebuilding enamel, many communities add extra to the drinking supply.

Arsenic

Arsenic occurs naturally in rocks and soil, and it’s linked to increased risk of cancer. A water-treatment plant should remove the poison.

Lead

Old, corroded metal pipelines can deposit this potent neurotoxin into drinking water, as they did in Flint, Michigan.

Hydrogen Sulphide

While naturally occurring and harmless, sulphide smells like rotten eggs, stains clothes, and corrodes pipes.

Algae

Algae in drinking water is just a nuisance: a musty, fishy taste that persists even after the treatment plant.

Medications

Everything from amoxicillin to Zyrtec makes its way into the rivers and lakes that supply our water. However, pharmaceuticals only contaminate surface water at extremely low levels.

Salts

Salts are a normal part of water, though a strong salty flavor can indicate a waste-water leak. And a high concentration of sodium- or magnesium-sulfate salts might have a laxative effect.

Copper

You’ll notice a medicinal taste—or even greenish hair—with just 1.3 milligrams of copper per liter of water. But the metal, which leaches from old pipes, is safe for humans at those levels. Just don’t put it in your fish tank.

 

We have used Popular Sciences’s  image and article and credit them as the source.