Excretion, A primer

Hello, Dr. Doches here. Holder is off for a little vacation... she asked me take over for her in her absence.



Let's talk excretion.

The human body can excrete waste products in 3 forms- solids, liquids, and gases. These can be released in many forms which we will examine in detail.

Solids

Solids are "leftovers" that are not usable by the body. Fiber, twigs, batteries, the occasional coin, along with cellulose, a sugar that plants use but we cannot digest. Corn, of course. Supposedly it take 24 hours for food to travel from stomach to toilet. Seems like it only takes three hours for me to shat the corn, but maybe that's just me. Our excreta takes on interesting colors. Mainly "Shit" brown- ever mixed all the paints together? What do you get? That's right- shit brown. Occasionally, stool can be green, orangey, red, or even blue, depending on how much spinach, carrots, beets, or blue cotton candy you've had, respectively. We also can excrete some compounds in solid form in our urine. Urea is the stuff in urine that makes it yellow or orange. Lesch-Nyhan Disease is often detected when toddlers have urea crystals in their diapers. A quick and dirty test for Cystic Fibrosis is to get your child sweaty and lick him/her. If the sweat is really salty, get checked.

As an aside- did you know that if you really want to lose weight but can't stand being hungry you can go on a diet of grass- any kind will do. Go out into your yard with a bowl after it's been freshly mowed and fill 'er up! Grass is made of cellulose- you'll feel full, but you get virtually no calories. The down side of course, is how to get that awful green stain off your teeth.

Back to solids- Peristalsis is a wave like motion in your digestive tract. Ever felt the gurgle as a really good fart moves towards the exit? That's peristalsis pushing that gas through. Go here for a moving video of the action.

Every now and again, it happens that a person will consume too much food, or tainted food. The stomach detects this and reverse peristalsis occurs- also known as Yarking.



Liquids

We are roughly 50 to 60 percent water, but like a toilet, we all need a good flush and cleaning out occasionally. That's why we have beer. No, really. OK, maybe not, but I'll tout my bad science anyway I want.
We need about 8-10 glasses... wait, no we don't, that's a myth. We need a liter or so of liquid, more if you're not just sitting on your ass watching the boob tube. Or reading this.

Remember the chick that held her wee for a Wii? Like we didn't see that lawsuit coming. Shit (or Peeee, as the case may be), as far as I'm concerned, that was just giving the gene pool a little flush.

I knew a guy that only drank distilled water. Here's the problem: Water is a polar molecule. That means is has a slight positive charge on one end and a negative charge on the other.

Now you need calcium in your blood so that your heart will pump correctly, sodium and potassium so that everything else runs smoothly and gets their messages from the brain. If you don't get enough of these elements, you'll end up like Terry Schiavo. Anyhoo, remember from chemistry when you learned the oxidation numbers of elements? Each of those elements also have a charge- positive. If you drink this charged water, the metals get stuck to the negative end of the water molecule and don't get to your bones, muscles, organs, brain, or heart.
Which is bad, unless you like the idea of being in a persistent vegetative state while your family rips themselves to pieces over you.



Our kidneys are responsible for keeping the water level in our body correct. They also filter out the nasty shit that gets into your blood stream. Beta carotene in the right quantities is good for you eyes, too much and you'll be wondering why people keep asking you "Orange you glad you like Sunny Delight?" Of course, if you smoke, you might want to skip that second glass.



We get rid of liquids when we exhale, too. Cleaned your glasses lately? Some of us have hot breath. Hot sticky breath. In need of a mint...

We get rid of liquids when we sweat- about a pint a day without extreme temperatures or exercise. I'm allergic to exercise.



Gases



I've saved this for last on purpose. Our primary form of gas excretion is respiration- breathe in, breathe out, breathe in breathe out, Machinehead... good song... Gas exchange occurs at in the alveoli. I love that word. Al-veee-o-lii. I should name my daughter that.

Of course, when we swallow, we also get a little air in our tummies. Get enough and you'll belch, burp, or yarp. If you're really talented, you can burp your ABC's.

Sometimes a little of that air makes it into our intestines and travels along with the food. We have bacteria in our intestines that help break down food and release vitamins. Without them, we'd be dead. They do us a favor and we pay them with a bit of our food and take out their trash. Which brings me to my final form of excretion- farts.

Bacteria make, as waste, methane and other chemicals like scatole and indole. Methane is natural gas, the stuff that comes out of your stove. Of course, methane itself is odorless, and must have mercaptan added to it to give it that distinctive smell. Indole and scatole contain mercaptans. When you fart, you are releasing methane that does not stink, but you also release indole and scatole. And those stink like...shit. So you see, it really isn't you that stinks, it's the bacteria in you intestines.



How can we not talk about releasing gas without talking about the quintessential Gas Bag himself? The Dean of Dukey? The Prince of Poo, the man who is so full of shit it's a wonder his eyes aren't brown-