Things you've always wondered and never known (or been too lazy to find out)

Written by: Rachel

I don't know if it's just me, but there's loads of things I've always wondered about but never known the answer to, or I've been to lazy to find out. In the quest for knowledge for all lazy PPTers I thought I'd find out the answers to some of your questions. If you have any questions, or general ponderings yourself, please PM or email me. As soon as I have enough I'll write another load of answers.

Why do we get brain freezes?

You might get a brain freeze when you've eaten ice cream or something else really cold- about 1 in 3 people will get them. It happens because you make the roof of your mouth really cold, but the pain associated with that is "referred" to your head, giving you a headache, which often lasts about 30 seconds.

Referred pain is when the pain is from somewhere in your body, but you feel the pain somewhere else. Another example of referred pain is in a heart attack, people often get pain down their left arm.

How can you stop yourself getting a brain freeze? Easy! Avoid touching the top of your mouth with your ice cream!

Why do we get dizzy when we spin round and round?

Dizzyness happens when your body thinks you're still moving but you're not. This all happens because as well has helping you hear, your ears have a really important role in keeping you balanced by telling your brain what position you're in and if you're moving.

Inside your ear there is fluid called endolymph. If you move, your endolymph moves too and tells your brain that you've moved.

If you spin around your endolymph will spin too, but if you suddenly stop, the fluid will carry on moving and your brain will you're still moving when you're not - this is dizziness.

Sooooo, if you spin round the other way it should help, because it will make the fluid change direction, and hopefully cancel out the first movement.

Why do cows have four stomachs and we only have one?

Cows are a kind of animal called ruminants, and all ruminants have four stomachs. Plant cell walls contain something called cellulose, which we can't digest as we don't make the right enzymes to break it down. As ruminants only eat grass they must manage to digest this cellulose, so they employ some bacteria to do the job for them. The first two stomachs contain bacteria that produce the enzymes required for cellulose breakdown. The third stomach allows absorption of some of the broken down nutrients, and the last stomach is much like ours.

We don't need to carry out all of this as we eat other things as well as grass so don't need to digest all the cellulose, so we only have one stomach.

Rabbits are another animal that have employed bacteria to digest cellulose for them. However rabbits have their bacteria at the bottom end of their digestive system, so they form two types of droppings; one kind that they eat as the bacteria have acted upon the cellulose, and the other kind which is the kind you would recognise as rabbit droppings.

What is that hanging thing at the back of our mouth for?

"That hanging thing" is called your uvula, which comes from the latin word for grape. There are many disagreements over what it is "for", however it is known to be involved in the creation of certain sounds and sometimes can cause snoring. Also, it is made of lymphoid tissue, the same tissue as your tonsils, so may also be involved in helping your immune system battle infection.

What does your spleen do?

The spleen is also made of lymphoid tissue, and contains many cells called macrophages that engulf and destroy old red blood cells and other debris in the blood stream. It also plays an important role in fighting infection by bacteria. It is possible to survive without a spleen, and splenectomies are relatively common, but do increase your risk of becoming ill from bacterial infections.

Thanks to zorg for helping me come up with some questions.