Booger science: the story behind the gross stuff growing in your head

Everyone reading this has at one point in his or her life stared at and seriously contemplated a chunk of freshly pillaged nose booty perched ever so slothfully on the tip of their finger. There's no reason to deny it. This unspoken secret will stay between you and DVICE. There is no judgment here.

And, while we're being honest, let's admit that these moments of grody Zen didn't stop with boogers. There's all sorts of weird crusty slimy fascinating things growing in and around your face. Everyone has them. Everyone is familiar with them. Everyone has wondered about them.

Since you're still reading, we can assume you've decided to indulge your natural curiosity as to who these little sticky friends are and how they came to live inside your face. Well, sit back and enjoy, for all the little pockets and crevices in your head are full of science! Disgusting, horrible science.


1. Boogers

There is no proper medical term for what is commonly referred to as a "booger," but without these sticky nasal ornaments, life would probably not be possible. The story of the booger begins with mucus. Mucus is a protective adhesive gel produced by all mammals and is present during times of health, as well as times of illness. Mucus membranes line the inside various parts of your body and produce this icky goo designed to block germs, pollen, and dust from making their way into the body. Human sinuses alone produce, on average, two liters of mucus every day.

When the respiratory tract becomes inundated with infection or irritants — such as when you have a cold or during allergy season — the body sends out a hidden army of white blood cells to combat the foreign invaders stuck in the mucus soup and, in the process, produce a thick slime known as "phlegm."

While mucus is clear, this diseased phlegm is typically a yellowish-green. The green hue is due to a combination of ingredients in this nasal gazpacho. The white blood cells create a nice whiteish-greenish base, but when you add in the blue and yellow (thus green) from the two most common human respiratory infections Staphylococcus aureus and Pseudomonas pyocyanea respectively, you're left with a sloppy, emerald-colored goop.

As air passes over the phlegm stored in the nose, it begins to dry out, eventually forming a semi-solid, sometimes crusty remnant that every kindergartener will instantly recognize as the irrepressible little green "booger."

Little known fact: Actress Scarlett Johansson sold one of her boogers on eBay for $5,300 for charity. We're not sure what the big deal is. It's just her body's natural defenses acting as they should.


2. Saliva

Mucus is a minor ingredient of another familiar face goo: saliva. People often confound saliva with mucus and phlegm because so much mucus and phlegm from the nose and sinuses drips down into the mouth from the back of the throat. The time-honored tradition of "hocking a loogie" is actually the act of drawing down phlegm from nose and sinuses into the mouth before expectorating (aka spitting). Saliva, however, is only produced in the mouth. It is the product of three specialized pairs of salivary glands inside the mouth: the parotid, sublingual and submandibular, each producing a slightly different saliva recipe.

On average, saliva is 98% water with the rest consisting of various chemicals including antibacterial agents as well as enzymes essential for kickstarting the digestive process. It is thought that humans produce one liter of saliva every day. This saliva production drops to near zero during sleep, paving the way for the formation of bacteria. Over the course of several hours, these bacteriopolises produce a small bounty of waste and excrement which we experience as "morning breath."

Little known fact: There is some science behind the term "licking your wounds." Researchers have long known that animal saliva contains a protein called nerve growth factor (NGF), which has been shown to heal wounds twice as fast as untreated wounds. Human saliva does not contain NGF, unfortunately. However, recent research from the Netherlands shows that antibacterial proteins found in human saliva, histatins, do in fact possess wound healing properties. Go humans!


3. Eye gunk

No, those little crusties you find in the corner of your eye in the morning are not the Sandman's footprints on the way out of your brain. It's a combination of mucus and mucin produced by the eye when mixed with excess cells and dust that collect as you sleep.

Various types of gunk collects in facial crevices as you slumber: in the corner of the eyes, the sides of the mouth, and alongside the nostril ridge (though the constitution varies for each orifice). When you're awake, your normal movements flush out this mess, but as you sleep, the gunk is allowed to collect in these little face pockets, most notably in eye near that little red dot on the inside corner, the Lacrimal caruncle (an evolutionary vestige in humans of a "third eyelid" that can still be found in many modern animals).

Contrary to the jingle, the best part of waking up is cleaning out your eye crumbs out of your vestigial third eyelid.

Little known fact: These collective face schmutzes are known as "rheum," but the eye crumbs are specifically known as "gound" (there's a nice Words With Friends word for ya).


4. Earwax

You may think that earwax are just boogers in your ears, but it's slightly more complicated than that. Earwax (scientific name "cerumen") is largely consisted of a specialized form of sweat produced by glands inside the ear that then combine with oils and dead skin cells.

Earwax production has been shown to increase during times of stress or depression. But these assorted, foul smelling ear crumbs will not only be able to tell when a person is under duress, but also their ancestry. Recent research has shown that a single gene determines if humans produce "wet" or "dry" wax, and the propensity for one kind of earwax or the other is intimately tied into regional origin. More than 95% of people of east Asian descent produce dry wax, while wet wax is the rule of thumb for people of African or European descent.

It is thought that earwax, like mucus, helps protect the inside of the body from bacteria, fungus, or even insects. It also helps keep the delicate inner ear lubricated and working properly.

Little known fact: Some types of whales build up large deposits of earwax through the course of their lives and can be used by researchers to determine a whale's age. Some scientists now believe these large deposits of whale wax are necessary for the animals to properly hear and process their intricate underwater whale jams.

Evan Dashevsky is a DVICE contributor and a professional word nerd for hire. Follow his cough-sized thoughts on Twitter @haldash.

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