As I said in my previous passion blog post, I have decided to dedicate my revamped passion blog to one of the most used parts of the body – the hands! Such amazing devices that can perform such a vast array of different tasks deserve some public recognition at least once in a while. (Much more often than they really receive it!)
So, first things first. What exactly are the hands? How is it that they work? You may be surprised at how many people actually don’t know the answer to this simple question, despite the fact that they use their hands constantly every single day.
As a side note, in order to avoid turning this into a dreadfully un-amusing biology lesson that uses incredibly technical terms, I’ll be simplifying and summarizing all of this information. But feel free to do more in-depth reading if you’d like!
Onwards and forwards. Let’s get the basics out of the way. Every hand has five digits, four called fingers, and the other called a thumb. Then there’s the palm of the hand (very nice for holding a ball, an apple, or any assortment of other objects) and the wrist, a hinge joint, which enables motion in the hand.
There are 19 bones in each hand, connected by ligaments and muscle structures. Then, of course, there is a layer of skin, as well as a nail (made up of keratin) for each of the hand’s digits.
Seen below, a man demonstrates one of the many things that hands are capable of doing as he uses a banana as a telephone.
Now, onto the good stuff. Both hands are controlled by, obviously, the brain. The right hand follows direction from the left hemisphere of the brain, and the left from the right hemisphere.
The control stems from two different types of muscles: extrinsic muscles, branching from the forearm into the hand as flexors and extensors, and intrinsic muscles that are just in the hand itself. The extrinsic muscles aid the hand in flexing and extending, and he intrinsic muscles allow for finer movements and motor skills.
Basically, through just these two types of muscles, the brain completely controls the movement of the hands, allowing us to do all sorts of incredible things. But to better put into perspective just how much I’m NOT mentioning about how awesome our hands really are, here’s a chart of all the muscles and bones in each of them, along with all their complicated names.
Be amazed a little more. Really wiggle and stretch those fingers and think about how great it truly is that you can do that! To think that something as basic as a finger tap, a gesture, or a hand twitch is dependent on so many other inner working aspects is absolutely mind-boggling. The human body is truly a work of art.
And so my very first lesson on hands comes to a close. Tune in next week as we begin to explore some of the hands’ “greatest hits” and astonishing achievements. Cheers!