- Kelly Shen ’23, image from Unsplash.com
Instead of the latest news, for today’s article I decided to compile a list of science questions we’ve all probably wondered at some point. So here are five science questions and the answers that you’ve been dying to know 🙂
1. Why do we die if we don’t drink water?
You know the answer to this one. We’ll dehydrate. But really, what’s the reason? Is it because our cells are drying up? Or is it because we can’t produce saliva and other fluids anymore? There are actually multiple reasons as to why we need water. The first is that we need water to produce sweat, because it lowers our body temperature. If we don’t have water to produce sweat, it makes it harder to regulate temperature, and can lead to an increase in body temperature. This puts pressure on other fluids like blood. If your blood volume is affected, less blood will be circulating in the body, leading to a severe drop in blood pressure. This can lead to unconsciousness or death. Finally, our kidneys need water to flush out toxins. Without water, we can’t remove the toxins through our urine and breath. A toxic buildup harms our kidneys, and can ultimately lead to organ failure.
2. What keeps our heart beating?
Your heart is controlled by electrical impulses. They travel down a special pathway to your heart:
- SA node (sinoatrial node) – also known as the heart’s natural pacemaker. It is a small bundle of cells located in the right atrium. An electric pulse sent from the SA node causes the walls of the heart to contract, forcing blood in the ventricles. It also determines the rhythm of your heartbeat. This is why normal heart rhythm is called sinus rhythm, because the SA (sinus) nodes is what causes the firing.
- AV node (atrioventricular node) – a cluster of cells in the middle of the heart. It acts like a gate that slows down the electrical signal before it enters ventricles. This delay gives the atria time to contract.
- His-Purkinje Network – pathway of fibers that send impulses to the muscular walls of the ventricles and cause them to contract, forcing blood out of the heart to the lungs and body.
- The SA node fires another impulse, and the cycle begins again.
3. How do fish breathe?
Fish live underwater, which means they can’t breathe air like we do. However, they still need oxygen. Instead of breathing air, they filter oxygen from the water. This means large volumes of water pass through their mouths and gills, these body parts act like a pump to make sure water is always moving over the gas absorption surfaces in their gills. These absorption surfaces then absorb enough oxygen to help them function.
4. How do we taste different sweet/sour/salty/bitter/spicy?
Ever wondered how you can taste different flavors? The taste buds on your tongue distinguish between different tastes by detecting the interactions of different molecules or ions. Sweet, savoriness, and bitterness are triggered by the binding of different molecules to G protein-coupled receptors on the cell membranes of taste buds. Saltiness and sourness, on the other hand, are perceived when alkali metal or hydrogen ions make contact with taste buds.
Fun fact: We have around 10,000 taste buds.
5. Why do cats purr?
Many people know the answer to this one: they purr to show that they are happy or content. That might not be the only purpose though. Cats also purr when they are stressed, or injured. This supports one theory, that cats purr for therapy purposes. At 26 Hertz, their purring falls in a range that promotes bone and tissue regeneration. Nuts, I know. High impact exercise promotes bone health, and so bones respond to pressure by becoming stronger. Since domestic cats don’t hunt as much, purring could stimulate bone growth in place of active hunting, helping to prevent their bones from becoming brittle.