Monday, January 31, 2011

The Brain: 5 Things Men Should Know

The brain is the focal point of our entire being. It is the mainframe, the hub and the central processing unit of all thoughts, emotions and actions. Even as such a vital component of human biology, the brain is still the least understood, housing mysteries that in this day and age still remain unsolved: How are memories stored and retrieved? Why do brains sleep and dream? What is consciousness? All these are questions without firm answers. But there are some interesting facts about the brain that have been uncovered and are not generally well known. Here are five things men should know about the brain.


1- Your brain is the most energy-consuming part of your body

Despite amassing to only 2% of our body weight, our brains demand 15% of our total heart output and 20% of our total oxygen to function. Talk about high maintenance! Perhaps more intriguing is that much of this oxygen is still needed when our brains are awake but resting, and this is for reasons that are not entirely known. So, our brains are demanding, but they demand without restraint or explanation. In order to achieve this insatiable demand, three major cerebral arteries are constantly pumping in oxygen. So vital is this demand that a blockage in any of these arteries is a one-way ticket to a stroke. Aside from energy, our brains also demand prime skull real estate. The expansion of the human brain over evolutionary time has left most of us with overcrowded mouths and, accordingly, little room for wisdom teeth. Oral surgeons may now rejoice.



2- Your brain was almost fully grown by age 7


Taking complex development out of the equation, it is true: Our brains are 95% of their adult size by the age of seven. This rapid growth probably explains why the brain of a 2-year-old consumes twice as much energy as the brain of an adult. Moving from diapers to briefcases -- once the human brain reaches its full adult size -- interesting contrasts become clear. Men, for example, have larger brains than women, a finding also observed in developing children. However, such differences should not, unfortunately, be interpreted as pointing toward any functional advantage (sorry, guys). In fact, this difference in size is due more to variances in specific regions of the brain than to an overall proportional difference. Women, for example, tend to have a larger hippocampus, the area of the brain responsible for smell and memory. Men, on the other hand, tend to have a larger amygdala and hypothalamus, but again, the effect of these differences is unclear.


3- Your brain doesn't feel pain


Do you ever wonder why some patients who undergo open brain surgery aren't sedated? The answer is laughably obvious: because the brain itself has no pain receptors, and hence, cannot sense any pain. A common headache is not actually caused by a stimulation of pain receptors in the brain. Instead, the membrane surrounding the brain, known as the dura mater, is innervated with pain receptors and is somehow involved in producing the pain felt during a headache. There are, however, many different kinds of headaches, and their exact causes remain unclear, so pinning an underlying cause to all headaches just isn't possible.



4- You use more than 10% of your brain


The common adage that we humans use only 10% of our brains is nothing more than a myth, perpetuated by movies and manipulated by paranormal pushers and psychics to explain the origins of psychic powers. The idea, of course, is completely false, but it certainly makes for an inspiring message. Imagine if we could unlock the other 90% of our brains! No one would turn down such an offer if it were truly attainable. Brain-imaging techniques, however, show quite convincingly that the vast majority of the brain does not lie dormant. Indeed, complex activities will use many parts of the brain. Observing the effects of head trauma also reveals that there is almost no area of the brain that can be destroyed without leaving the victim with some functional deficit. It's sad but true: We use most of our brains, if not all.



5- Brain cells regenerate


There is something to be said about mystery because with it comes a lot of myth. Another thing you thought you knew about the brain -- a belief that has literally persisted for 100 years -- is that brain cells don't regenerate. However, thanks to work conducted over the last decade or so, we now know that they most certainly do. Modern science now shows us that even neurons can be persuaded to regenerate. This should come as great news to alcoholics everywhere who should also know that drinking does not, in fact, kill brain cells but instead damages the connections between the neurons, the synapses. Who knows -- maybe one day, science will find a real cure for hangovers too.