Learned #37: Ear Ye, Ear Ye

In which we learn to ear.

My ear itches. It's not dangerous and there's not really much to be done about it except to go to the doctor and listen to him tell me there's not really much to be done about it. Again. See, the thing is, I have several stray hairs growing in my ear canals. Chances are, so do you. It's weird, it's kind of gross, and it's a real pain in the...ear.

I first found out about these random hairs a few years ago when I went to the ear-nose-throat doctor to have a strange earache investigated. He put a camera into my ear and then clipped three six-inch long hairs out my ear. Now, my reaction to this was one of shock - I didn't know that this was a thing that could happen. But, apparently it is a common ailment and one we don't get diagnosed as often as we should because most of the time it isn't a problem.

The whole situation got me to wondering. I mean, I know lots of people who have had lots of problems with their ears. And their sinuses. And all the...stuff...or space...or somethings in between their ears and nose...areas. Which made me realize I have no sense of the internal anatomy of the human head. I mean, I know where the major parts go, and I kind of remember the parts of the brain. But, as for the rest of it, especially how it's all connected (or not), I really have no idea.

This week, we're going to try to fix that.

In this issue:

  • What We're Learning: Inside the Human Head

  • What We're Reading: Gray’s Anatomy

  • Down the Rabbit Hole: Lemme Take Your Picture

Let's get to it.

Photo by Hugo Barbosa on Unsplash

What We’re Learning:

Inside the Human Head

As with all complicated, in-depth questions and processes, the best way to begin understanding the subject is to break it down into smaller, more manageable questions. In this case, we'll start with the ear and how it works.

The Ear

Now, chances are good you know what an ear is and have a basic understanding of how it works, but let's review: The outer ear catches sound waves. These sounds then travel through the middle ear where they hit the eardrum, causing it to vibrate. The resultant vibrations then travel into the inner ear and the cochlea, where they are translated into nerve impulses your brain interprets as words and noises, etc.

What's especially important to understand is that your inner ear is what determines your balance:

In the inner ear, there are three small loops above the cochlea called semicircular canals. Like the cochlea, they are also filled with liquid and have thousands of microscopic hairs.

The liquid moves the tiny hairs, which send a nerve message to your brain about the position of your head. In less than a second, your brain sends messages to the right muscles so that you keep your balance.

(Source)

This very useful diagram comes from HearingLink.org.

The Sinuses

The sinuses, as it turns out, are not really a function of the ears. I'm going straight to Wikipedia for this one:

Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sphenoidal sinuses are behind the eyes. The sinuses are named for the facial bones in which they are located.

Groovy. But, nothing to do with the ears except that when one is inflamed the other may also hurt. In other words, a sinus infection might make your ears hurt and vice versa because...

Connections

Aside from physical proximity, the nose and ears (and the throat) share similar functions (senses) and are constructed out of the same toolkit (membranes, lots of tiny hairs, fluids, etc.) But, the best way I can put it all together so that I can understand exactly what is going on in my skull is by using ZygoteBody - an online anatomy viewing tool (and that used to be Google Body).

This tool lets you look inside the human body in different layers and from different angles. For the screenshot I have here, I've loaded the adult male body, put the brain at full opacity (most visible) and the bones and nerves at half opacity so that I can zoom in and take a look at how it's all connected.

With a lot of this I don't know, or have forgotten, the proper names of the different parts, but that's not the point of this exercise. Using ZygoteBody lets me get an actual, textbook-like view of how everything works together. And, at least in this case, that's what I was really looking for.

So, About that Hair?

But, back to my main issue - what's up with the hair in my ears? It seems to be normal and a result of aging and testosterone.

Hair growth within the ear canal itself is limited to the cartilaginous ear canal – roughly the outer 1/3 of the ear canal. The inner 2/3 of the ear canal, called the bony ear canal, does not have sufficient dermis and hypodermis underlying the epidermis to support the hair root in the hair follicle. Therefore, ear hair is not found in the deeper (bony) structure of the ear canal. Hair growth within the outer portion of the ear canal seems to increase and become stiffer as men age (along with an increase in nasal hair growth).

(Source)

However, there seems to be some indication that ear-hair growth and/or a creased earlobe can be a predictor of heart disease (as in who may be more or less susceptible). Before you examine yourself in the mirror and panic (like I did), remember that nothing written on the web beats discussing your individual body and health with your doctor. Now then, I'm off to consult with my cardiologist and then a laser hair removal expert. In that order.

More sources:


What We’re Reading:

Gray’s Anatomy

by Henry Gray

In a perfect world, we’d all have libraries in our homes, leather-bound volumes of art science shelved on each wall with curiosities and oddities stuffed into every nook and cranny. Alas, it’s not a perfect world and the best we can do, sans personal library, is build a collection of interesting and lasting books.

Gray’s Anatomy is the standard from which much of modern medicine is derived. Written by Henry Gray and Henry Vandyke Carter, the book has been reprinted and updated often, never having lost its original purpose, to educate: From Wikipedia:

In 1855, he (Gray) approached his colleague Henry Vandyke Carter with his idea to produce an inexpensive and accessible anatomy textbook for medical students. Dissecting unclaimed bodies from workhouse and hospital mortuaries through the Anatomy Act of 1832, the two worked for 18 months on what would form the basis of the book.

Like a lot of reference books, most of what’s relevant to the layperson has been indexed and made discoverable by Google. But there’s a certain feeling to holding a book like this on in your hands, in actually looking up whatever it is you want to know and reading off the page.

In lieu of an original, 1858 edition, this nice leather-bound version will look handsome on any shelf. But, for those of us who need a more practical guide, there’s always this


Elsewhere:

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Down the Rabbit Hole:

Lemme Take Your Picture

Over the past few years, my wife and I have both had to have physical examinations for the insides of our bodies (my ears, her stomach). In both cases, the doctor was able to use a tiny camera connected to a monitor to more easily and accurately get a picture (ahem) of our insides. Medical cameras are a fascinating technological development that got me to thinking about other new, non tourist-issue cameras.

To start with the obvious, our the cameras in our phones have been getting better and better; what might not be quite so obvious is that the software that runs the cameras is what makes them so good, not the lenses or sensor size.

While medical cameras are getting small, other cameras are getting bigger and bigger. Then again, they used to be pretty big, so maybe it’s just the cycle coming ‘round again.

Speaking of small, it turns out that those 007-style spy gadgets and cameras were not completely fictional. What’s more, there are dozens of modern spy cameras on the market and some of them are frightening in their implications.

And it’s those implications that has us creating new privacy laws and standards - like in Japan alone (where I live), the shutter sounds on phone-cameras cannot be disabled, taking someone’s photo in public without their permission is prohibited, and drones are limited to very secluded areas.

This is all a bit crazy and getting crazier. In Neal Stephenson’s The Diamond Age, there are swarms of flying, floating cameras that act as a single lens, but that’s just fiction, right?

Random Fact:

The Japanese title of Pixar’s Inside Out is Inside Head.

That’s it. Stay strong, stay healthy. Learn something.