August | 2015 | Forgotten Physiology

I’ll bet her hand tells the best jokes

You may not know this but…

we are in possession of ancient technology. I’m talking about Men in Black, Star trek phaser-level technology. Forget about your smartphone or the connectivity of your Wi-Fi to your oh so shiny tablet (yeah..your tablet is boring). We have ears! Do you understand how remarkable the phenomenon of hearing is?! Mammalian ears are a curiously sophisticated adaptation. They’ve crossed species borders and traveled the millennia just to stay virtually the same. As far as mammals are concerned, version 1.0 is still the best thing out there and those cute little ears of our furry ancestors have been around since the dinosaurs. Archaeologists in China discovered the fossil of a 195 million year old mouse-like mammal (Hadrocodium) with a fully developed inner ear, not unlike what we have today. That’s the physiological equivalent of finding King Tut’s blue-ray collection.

Do we hear with our ears or with our brains?

Sound Waves and Philosophy

Sound is a physical property. Sound happens because people and animals and objects interact with the physical environment and the resulting energy of those interactions is transferred into sound waves that travel through air, water, asphalt or whatever. What we “hear,” on the other hand, is what our brains say we hear. Our brain translates that physical phenomenon into an experience and our brain instantly labels that experience as familiar or unfamiliar, safe or dangerous, pleasing or Nickelback.

Ear Anatomy

The pinna, that floppy, fleshy, flap of skin and cartilage on the outside of our heads is a total cover girl. It’s the most recognizable part of the ear and it helps to funnel a small portion of the infinite variety of sound waves whizzing pass our heads every second of the day. However, to learn the secret to the riddle of sound we need to look beyond the pinna, down the icky, wax filled canal (external auditory meatus) into the middle and inner ear where the tiny bones and membranes play percussion for our central nervous system.

ear-anatomy

The path of sound…

Tempanic > malleus > incus > stapes > oval window > vestibules > cochlea > Brain!

Once sound waves slinky down our ear canal they reach the tempanic membrane (ear drum) and that’s where the magic really happens. Waiting just behind the tympanic membrane is a highly specialized set of tiny bones (ossicles) that move in sync with each vibration.

At this point we have this nifty domino effect happening where vibrations move from one tiny bone to the next. That’s right, I said “vibrations.” Sound is energy and it behaves the way all energy does, never destroyed just moving from one form to another.

Anyway, vibrations move from the tympanic and then pass the baton to the malleus, along to the incus, and then to the tiniest bone of all, the stapes.

Here’s where it changes up a little. Those 3 bones I mentioned occupy this air filled space (tympanic cavity), kind of like a hallway in your head and at the end of that hallway is a door (or rather a window), the oval window. This window is a part of the next compartment of the ear. When that vibration reaches the stapes it basically knocks on that window, handing off the remaining sound energy to the inner ear.

Keep in mind that this is all happening at the speed of sound. Sound waves gallop along at a healthy pace of 1,126ft/sec through the air. Just imagine jumping 13 train cars in a fraction of a sec. Of course, your ear canal is only about an inch long so this all happens MIGHTY quick.

The inner ear is like another dimension. There are fluid filled vessels and a chamber at the end shaped like a snail shell with hairy receptor cells transmitting signals to the brain. I mean What?! It sounds like the hallucination of a band groupie at a Pink Floyd concert, but it’s real.

So what happens?

The stapes knocks on the oval window, transferring the sound vibration to fluid contained behind the window that will move along tubular ventricles.

So in case you got lost, sound moved down the pinna, through the canal, to the tympanic, shaking hands with the malleus, incus, and stapes hanging out in the hallway of the tympanic cavity where the stapes bangs on the oval window to stir up some nasty fluid on the other side.

This fluid (endolymph) now surging with sound energy, will transmit vibrations within the coiled vestibules where they connect with a spiraled chamber called the cochlea.

OK…here it is..

Tucked inside the cochlea is a layer of epithelial receptor cells that make up the Organ of Corti. As the energy charged fluid passes over the tiny hairs of these cells an electrochemical signal (neural transmitter) is released. Neural transmitters are basically like biochemical text messages, but instead of going through Verizon or Sprint this message travels down a bundle of nerves called the spiral ganglion where the temporal lobe of your brain is waiting to…well..”hear” it.

Stay curious, stay classy, and never stop learning my friends 🙂

“Really, calories again?” Yes, I can just feel your eyes rolling from across the internet, but don’t worry, I’m not here to point out every
bad decision you’re making with your diet. Trust me, I’m eating a blueberry doughnut right now and it’s not for the vitamin C. Today
I want to go “behind the music” of one of the most notoriously misunderstood bad boys in nutrition today, the calorie.

True story…

Manufacturers will use terms like “50% less calories” and “50% less fat” interchangeably on the labels of everything from candy bars to ground pork to persuade consumers, because they know a simple, ugly truth; many of us don’t know the difference.

The Lie…

calories = fat (NO!)

The Simple Truth…

Fats contain calories (YES!) and so do proteins, carbs, and alcohol

– so if Katie and Sara both order tall chai lattes but Katie orders the reduced fat latte (because you know how Katie is) then Katie’s drink will have fewer calories than Sara’s, because there are fewer fat based calories present (and because Sara lives on the edge).

Simply put, a calorie is a unit of measurement for energy, heat energy. In chemistry it’s the amount of energy needed to raise the temperature of 1 gram of water by 1 degree. We call this a “small” or gram calorie. It is, as French scientist Nicolas Clement
described it, a unit of heat.

The calorie we commonly associate with nutrition is a large or kilo calorie. One kcal provides the energy required to raise 1kg or 1000
grams of water by 1 degree.

WHOAH!…………Chord change……..SLOW IT DOOOWWwwnn..

I’m just saying…

What does that have to do with food?

When we talk about the calories in foods we are describing how much potential energy per volume (grams/fluid ounces) is locked
inside that grilled chicken Caesar wrap or the salted-caramel frappuccino you’ve convinced yourself is not a milkshake. That energy is
released once we ingest the wrap and our digestive hardware gets busy metabolizing the fats, proteins, and carbs.

Fats, despite what you think about them or their political views, have more than 2 times the energy of carbohydrates or protein. The
chemical bonds holding fat molecules together just have more juice in the battery.

See what I mean:

Fat: 1 gram = 9 calories
Protein: 1 gram = 4 calories
Carbohydrates: 1 gram = 4 calories

and so what’s the problem with fat?

First let me say everybody needs to ease off on the recent, anti-fat campaign. We need fats to operate. The lipids and triglycerydes in fats line our cell membranes, make up the bulk of our hormones, and even insulate our neurons.
The problem with fat is storage. Fat just tends to hold on to more calories than we can use at one time, and what we don’t use gets stored right out in the open for everyone to see (I’m looking at you love handles).

We do burn fat for energy at some point. Carbohydrates are just more readily available since they are essentially just long chains of sugar molecules. Metabolically speaking, sugar is as easy as paying with a debit card as far as your cells are concerned (fat is like an old, wrinkled check folded up in your wallet). When the carbs get used up we begin to breakdown fat in a process called ketosis whereby enzymes acting
on fat cells persuade them like cellular loan sharks to give up their precious triglycerides (composed of a glycerol and three fatty acid chains) which then venture out into the bloodstream to make themselves available for cellular respiration and ultimately ATP synthesis.

Believe it or not, even fat burns calories, just not as efficiently as muscle cells. Your resting metabolism (A.K.A basal metabolism) is burning calories just to operate. The body is a machine whether you like that analogy or not and it burns fuel just to keep the engine running. We even burn calories when we digest food. Fats not only have more calories, it takes fewer calories to digest them. They’re
like a roommate that only has to pay a fraction of the rent but has 3 times more stuff than you just cluttering up the living room.

Muscle on the other hand is a calorie burning mad man. It is metabolically expensive for the body to maintain muscle tissue because muscle fibers work hard and demand compensation (talking about calories…see what I did there?). So if you truly want to burn calories you need to improve the ratio of fat to muscle in your body.

that’s so 90’s

The way I see it (A.K.A the right way, most awesome way, best way, etc.) we need to change our philosophy about exercise. Sure, we want to burn calories, but that would involve burning more calories than you consume and that’s about as effective as hiking up a ski slope with roller blades on…which is pointless and just way too 90’s.

Perhaps we should exercise with a mind-set to condition and build muscle. That way your metabolism can start working for you and not against you. Of course, it also helps to limit the amount of fat based calories your body would need to burn in the first place. Sorry, nothing is ever easy. I don’t care if you call it a diet or not. There’s just no such thing as a reduced fat “Baconator.” If you cut out fast food then you’ve done half the work already. Hey look at me,…I care.

Stay curious, stay classy, and never stop learning my friends 🙂