I don't know why this cracks me up so much, but I love it.
Saturday, June 9, 2012
Friday, June 8, 2012
It's movie season right now, so today's post is both topical and fairly practical. On a very related note, go see "The Avengers", it is amazing. Seriously, stop reading right now, and go see it if you haven't already. It really is that good.
Also, buckle up your seat belts, this is gonna be a long one. But it's totally worth it. Probably.
Anyway, back on topic. When I go to the movies, I get my coke and my salty popcorn, settle into my cushy seat, and prepare to be entertained. Then about 5 minutes into the movie, I feel like I haven't peed in weeks. So I sneak off to the restroom, take care of business and come back. I get all situated and prepare to enjoy the rest of the movie. A half hour later, it hits again. I have to pee so badly I'm considering urinating in my now empty soda cup because I'm not sure I can make it to the bathroom in time. Once again, I creep past everyone else, empty my bladder, and then stumble around blindly trying to find my seat, where I remain for the rest of the movie. When the credits finally role around, I jump out of my chair and bolt for the restroom one last time. And this happens every movie! But why? Let's take a look at the physiology.
There are two major players here in this crazy game of "Don't Wet Your Pants", the first is water. Most of that 32 oz soda I'm guzzling down is water. When water comes in the body, it also must leave. This part is straight forward.
The other player in this dangerous game of "try to leave the movie seat as dry as when I sat down", is sodium. Sodium makes up half of what we call salt. Salt's chemical compound is NaCl, which means that it is made up of equal parts sodium (Na) and chlorine (Cl). And if you are like me, you dump salt all over your popcorn. But sodium isn't just found in salt, there is also a very significant amount in coke (and in most soft drinks).
So we have two ways of sodium getting into our bodies right now, salty popcorn and our soft drink. Why is this important? Sodium loves water. Or maybe water loves sodium. I don't know which it is. All I know is that if you see sodium go to the park, water follows right along and goes to the park too. Or maybe it's that sodium goes to the park and loves water so much that he brings water along with him. And they go to the bank together, and the gym, and to the movies, and grocery shopping, and they go down slides together, and they have nerf gun fights. They really, really like each other, whatever the relationship is.
Anyway, sodium is readily absorbed into the body by the small intestine (specifically in the jejunum). So as sodium is leaving the small intestine, it says to its buddy water, "Come with me, it'll be fun!". So water, being the great molecule it is, follows its pal sodium into the body. (There are plenty of other molecules that bring water into the body with them, like glucose, but today our big focus is on sodium)
Now we just talked about how much sodium we take in at the movies - a lot! All of that sodium pulls in all the water from your intestine into your blood along with it. Now you have an influx of fluid into your blood stream. And this is no turn on the faucet, and fill up a water balloon flow, this is open up the fire hydrant and fill up that same water balloon flow. The good news is that your body knows how to deal with this sort of conundrum. Your body knows that exploding from too much water coming in is a bad thing. And while there are a couple of different response systems, since I just got done with cardiology, we will talk about how the heart response affects things.
The heart has stretch receptors inside of it in a portion called the atrium. These stretch receptors do exactly what they sound like, they alert the body when they are stretched. And the only normal way they get stretched is when excess fluid comes in the heart and pushes up against them. When these receptors get activated, they send out a signal called ANP (Atrial Natriuretic Peptide - atrial = atrium, natriuretic = sodium, peptide = signaling protein). ANP travels by blood to the kidneys where it tells the kidneys to get rid of sodium. The kidneys send sodium into the urine. And like we talked about earlier, wherever sodium goes, water likes to follow. So we send out a ton of water into our urine. The bladder fills up rapidly and then you feel like you have to pee. This will continue to happen as long as the heart feels stretched enough to send out ANP. Or basically until you stop cramming your face with salty popcorn and sodium-filled soft drinks.
So how can we prevent this, or at least lessen the effects of this? The obvious way is to not eat salty popcorn or drink soda. Bam! Problem solved.
But if you are like me, and you love your movie treats, then there are other ways. The first is to limit the salt on your popcorn and drink a soda with less sodium in it (a good rule of thumb is clear sodas have less sodium, colas have more, and diet sodas have more). Or you could try eating a fatty meal right before you went into the theatre. This would slow down the whole digestion process and possibly delay the water absorption for long enough that you could finish your movie in peace. Of course you would suffer for it later, but we aren't dealing with that here. We just want short-term results. Another option is to have a folley catheter inserted, then you could just have your bladder drained while you watch. You could drink 3 or even 4 sodas and have like 20 bags of popcorn and not have to run to the bathroom once.There is the possible complication of a urinary tract infection or other worse things (much, much worse) but it's an option to keep on the table.
The last option is Depends. A pair of adult diapers is both practical and beneficial. I don't know about you, but I usually end up freezing in the movies and it wouldn't be a bad thing to have some extra warmth mid-way through.
However you solve the problem, at least now you know the physiology behind it.
(Also, sorry for the boring stock photo at the beginning. I just couldn't find anything funny that fit and wasn't too inappropriate. So here is a funny pic that is somewhat inappropriate and has nothing to do with the post)
Thursday, June 7, 2012
After a month long hiatus, it would appear that I feel like writing again. Or maybe it's that my creativity reservoir is bursting at the seams and is threatening to destroy me if I don't find an outlet. I think we will find over the next few days that is simply not the case. Creativity is not my strong suit. My brother got the artistic, good looking, athletic genes, and I got... personality? And really, let's face it, he has way more personality than I ever will. But I can do one thing, I can write. Yes, my strong suit is something a monkey can be trained to do, but you gotta hold on to what you can.
The real reason I'm back is because I'm finding that I need to have some goals this month. While I do get to have the month off in anticipation of my daughter being born, she hasn't come yet and quite frankly I'm a little bored. And so I turn to the web. Sorry.
I have a great Physiology Friday post for tomorrow all about urinating. It's pretty awesome. Stay tuned. Also, I have been collecting funny pictures for the past month, so I haven't been too lazy and I do plan to share these daily. And finally, marriage posts, medical stories, and other things that interest me will continue to appear on a daily basis.
Tuesday, May 8, 2012
I worked hard on writing a lot of new content this weekend. Unfortunately I also went and saw Avengers twice. So I didn't get as much done as I should have. I also have a case presentation due tomorrow morning. So here's the dealio, a funny picture or two today. Tomorrow and Thursday will see Marriage posts and Friday Physiology is on like Donkey Kong.
Friday, May 4, 2012
Okeedokee, today is a big one and it may look a little daunting, but it will be totally worth it in the end. I pinky swear.*
Also, I finished this up last night around midnight, so if there are more mistakes than usual, sorry. I'm just too lazy to go through it all right now and proofread (but not too lazy to type this explanation apparently). Anyway, on to the good stuff.
My son was having some troubles going down for naps a while back, so drawing on my own childhood, I turned to a little medicine my folks used to give me to help me sleep: milk (some of you were probably thinking: vodka! Shame on you. Straight vodka is not good for kids. White Russians on the other hand...).** And low and behold it worked. So now before naps and every night before bed, we give our 16 month old a glass of warm milk to help him fall asleep. Could there be some physiology behind it?
People have been using warm milk as a sleep aid for millions of years. If I had to guess, I'd say it correlates with the invention of the microwave. So, probably for the last 2 million years. Before that, they used to just give each other a little smack on the head with a club to help each other sleep (Note: I do not in any way condone domestic violence). But why warm milk? Is warm milk just like a little kid needs his teddy bear to sleep? Is it more psychological than anything else?
There are two theories currently in play right now. The first has to do with proteins, neurotransmitters, the pineal gland, and biochemistry. Big words. But it's not too complicated. So let's break it down.
Remember the pineal gland from back in high school? Probably not. I can barely remember what it does and I'm gonna be a doctor one day. The pineal gland is in charge of keeping time in the body. It does this through a hormone called melatonin (not to be confused with melanin which is in charge of skin color). Melatonin levels are high at night and low during the day. High levels tell your body it's time to sleep and low levels tell your body it's okay to be awake. So if we could artificially increase melatonin levels, we could trick the body into thinking it is sleepy time.
Now for some biochemistry. Melatonin is made from serotonin, which is really a cool hormone and will probably be a topic in the future, but for now, nobody cares about it. Except, that serotonin is made from a protein called tryptophan. So to summarize, tryptophan leads to serotonin which leads to melatonin which is how your body tells time.
When you warm up milk, it releases more tryptophan. So the theory goes that taking in excess tryptophan leads to increased melatonin. High melatonin then makes the person sleepy. While this works on the surface, and may play a small role, it does have some physiology issues. Tryptophan needs high amounts of insulin to cross into the brain. Insulin comes about when the body sees lots of sugar. Drinking milk shouldn't normally cause the high levels of insulin needed for a huge influx of tryptophan into the brain. So for milk to work, a bunch of carbs should be taken with the glass to help stimulate insulin and thus help melatonin cross into the brain. People don't usually load up on sugar right before going to bed though. So this probably isn't the major contributing factor to the sleepiness.
The second theory gets away from the big words for the most part and is the one I currently subscribe to.
Here's what is probably happening. Whole milk has a lot of fat in it. We give our son whole milk, the Romans gave their kids whole goat milk, ancient cave men used to give their kids milk straight from the stegosaurus. Whole milk is probably best for this to work. It sits in the stomach for a little while because of the fat and convinces the body that a good full meal was just eaten and so your body goes into "rest and digest" mode. When the body goes into the "rest and digest" mode, it shunts blood to the GI system and away from the periphery, which includes the brain. When the brain doesn't have blood, it doesn't have oxygen. Lack of oxygen tells the brain to go into sleep mode. And voila! Sleepy time.***
This is a temporary situation though. The body won't be fooled by the milk for long and will eventually return things to normal. So if you are going to drink milk, do it right before bed.
For those of you looking for a nice neat summary, we probably have a combination of the two at play - tryptophan increases the melatonin a little bit and contributes to sleepiness, but the large glass of milk telling hour body to send blood away from the brain is probably the main factor. Either way, milk is good for sleep and now you have some science to back it up.
*Legal note: pinky swears over the internet are non-binding and should not be considered as a real contract unless actual pinky-to-pinky contact was made in the physical world
**Please do not give your children alcohol ever, even if it sounded like a good idea when you read it on a blog.
***side bar - this explains why you feel sleepy right after lunch when you head back into work. Most people grab a McDonalds or some other fast food high in fat. Your body thinks it needs to supply your digestive system with blood and it borrows from the brain's supply. If you were to eat a small meal at lunch and another snack a couple of hours later, you would probably find you are less sleepy and have more energy to make it through the afternoon.
Thursday, May 3, 2012
So my son, who is 16 months old, had blueberries for breakfast. He would smash them under his index finger while pretending they were crying out in pain. I've raised a sadistic tyrant.
Anyway, cardiology is keeping me running around early mornings and late nights. It's a lot of fun and my doc is amazing. Seriously, if you need a cardiologist, I would go to him, most of the nurses at Mercy Gilbert would choose him (according to a very informal poll) and he's where I would send my family if they have heart problems. But I don't have time to post regularly. The good news is, I almost have a Physiology Friday post ready. So let there be rejoicing in the land. My son may be a tyrant, but I'm a benevolent dictator. And I'm still in charge, for now.