Posts Tagged ‘Physiology’

One more reason to get a good night’s sleep

October 19, 2014

The brain uses a quarter of the body’s entire energy supply, yet only accounts for about two percent of the body’s mass. So how does this unique organ receive nutrients and, perhaps more importantly, rid itself of wastes? New research suggests it has to do with sleep.

Back in 1942, we averaged almost 8 hours of sleep a night — now that’s down to 6.8. (Seven to 9 hours per night are what’s generally recommended.) For a list of 25 more unfortunate risks of partial and total sleep deprivation go here.

How do we smell?

April 14, 2014

An adult human can distinguish up to 10,000 odors. You use your nose to figure out what to eat, what to buy and even when it’s time to take a shower. But how do the molecules in the air get translated into smells in your brain?

Human nose can detect 1 trillion odours

March 24, 2014

For nearly a century, scientists assumed the human nose was capable of discerning about 10,000 different odours. Turns out, that number was missing a whole bunch of zeroes — new research shows that the human nose can detect over 1,000,000,000,000 distinct scents. Tell your dog to quit being so smug.

Lady nose

In fact, one trillion estimate is actually on the low end. And while you probably don’t encounter a trillion different odours in a given day (I hope), the capability to discern new scents means your nose is ready for whatever changes your environment presents. Learn more here or here.

How Does Your Memory Work?

February 22, 2014

All our brains are wired in much the same way — and it requires quite a few steps to remember anything at all.

What percentage of your brain do you use?

February 13, 2014

Two thirds of the population believes a myth that has been propagated for over a century: that we use only 10% of our brains. Hardly! Our neuron-dense brains have evolved to use the least amount of energy while carrying the most information possible — a feat that requires the entire brain.

What happens if I swallow chewing gum?

January 5, 2014

So what actually happens when you swallow chewing gum?

The big answer is nothing really. As you chew you absorb all the sugars and flavouring. If you swallow, the chewing gum just passes through your digestive system and quite literally poops out the other end. Lovely.

Why Teenagers Are So Impulsive

November 27, 2013

Why do teens—especially adolescent males—commit crimes more frequently than adults? One explanation may be that as a group, teenagers react more impulsively to threatening situations than do children or adults, likely because their brains have to work harder to rein in their behaviour.

Whether it’s driving too fast on a slick road or experimenting with drugs, teenagers have a reputation for courting danger that is often attributed to immaturity or poor decision-making. If immaturity or lack of judgment were the only problem, however, one would expect that children, whose brains are at an even earlier stage of development, would have an equal or greater penchant for risk-taking. But younger children tend to be more cautious than teenagers, suggesting that there is something unique about adolescent brain development that lures them to danger.

Brain region associated with restraint.

Brain region associated with restraint.

In an experiment to test impulsivity when faced with a threatening situation, adolescents showed significantly higher activity in a brain region called the ventromedial prefrontal cortex (vmPFC), which is involved in top-down control of behaviour. You could think of it as the brake. It’s as if the teenage brain might need to work a little harder than others to hold that response back. This could help explain why teenage criminals are less likely to be repeat offenders, as their brains develop into adulthood, it gets easier for them to rein in their behaviour. Learn more here.

Universal law of urination found in mammals

October 30, 2013

Elephants, cows, goats and dogs all take roughly 21 seconds to empty their bladders. A “law of urination” now explains the physics behind what happens when you just gotta go.

Scientists filmed rats, dogs, goats, cows and elephants urinating and gathered footage from YouTube of others relieving themselves. Combining this with data on mass, bladder pressure and urethra size, they were able to create a mathematical model of urinary systems to show why mammals take the same time to empty their bladder, despite the difference in bladder size.


And very weird scientific research, learn more here if you really want.

‘Safe’ levels of sugar harmful to mice

August 22, 2013

Too much sugar is bad for you, but how much, exactly, is too much? A study in mice has found that the animals’ health and ability to compete can be harmed by a diet that has sugar levels equivalent to what many people currently consume.

High-sugar diets are associated not only with obesity and diabetes, but also with other human conditions such as coronary heart disease.


Scientists gave mice a sugar diet not dissimilar to many humans. After 26 weeks on this sugar binge, the mice were released into a large habitat that mimicked their natural environment and were left to compete for food and territory with an equal number of control mice that had been fed a healthy diet. The sugar-eaters did not fare well. Over the 32-week duration of the experiment, sugar-fed females died at nearly twice the rate of control females and the males controlled about one-quarter less territory and had one-quarter fewer offspring than their control counterparts. Learn more here.

Get a standing desk

July 27, 2013

An interesting question to ask scientists who study health hazards is whether their research has led them to change their own behaviour. By that rule of thumb, Michael Jensen of the Mayo Clinic in Rochester, Minnesota, is worth heeding. A leading light in research on the health effects of too much sitting, he has started working at a treadmill desk.

Why? The emerging consensus from work by Jensen and others is that long periods of sitting down – such as when watching TV or working at a desk – are bad for your health regardless of how active you are at other times. Simply standing up, or walking gently on a treadmill, allows you to escape the effect. Hence the growing trend for “active” workstations and stand-up meetings. Desk jockeys take heed – and their employers, too.

standing desk ergonomics

Learn more here.


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