Why do we shiver when we are cold?

We shiver in an effort to keep ourselves warm. The human body needs to stay at a temperature of 98.6 degrees Fahrenheit. When you feel cold, tiny sensors in your skin send messages to your brain. In an attempt to avoid hypothermia (where the body temperature drops to dangerous levels), your brain sends messages to nerves all over your body, telling your muscles to tighten and loosen really fast in order to generate heat. This type of muscle movement is what we call shivering.

Shivering when we’re cold is just one of the ways our body works to maintain itself. The human body has many incredible systems that help keep it running smoothly. Our body has homeostatic functions, theautomatic monitoring, adjusting, and regulating of our vital systems that happen without us even knowing it. Besides shivering, which helps regulate body temperature, some examples of homeostatic functions include breathing and heart rate.

What is a funny bone?

Have you ever banged the inside of your elbow in a specific spot and felt tingling sensations shoot down your forearm? Well, that means that you hit your so-called funny bone.  These sensations feel kind of strange as opposed to being painful. That is one of the reasons why it is called the “funny bone,” because of the funny feeling you experience after you bang it.

But the funniest thing about the funny bone is that it is not actually a bone! It is a nerve! Running down the inside part of your elbow is a nerve called the ulnar nerve. When you hit your funny bone, you’re actually hitting the ulnar nerve against a bone and compressing it. The result is the tingling and numbing sensation that shoots through the areas where the nerve does its work: down the forearm and hand and into the ring and pinky fingers.

What determines our hair color?

Hair color is the result of the mixture of two types of melanin: eumelanin and pheomelanin. Melanin is a pigment that determines the shade of our hair (and skin and eye color).

The reason why there are so many varying shades of hair color is because different bodies produce different amounts of eumelanin and pheomelanin, resulting in completely different mixtures of the two.

If you have high levels of eumelanin, your hair will be darker, and if you have low levels of eumelanin, your hair will be lighter.Pheomelanin colors hair orange, red, or yellow, while eumelanin can color hair either black or brown.  A low concentration of brown eumelanin results in blond or red hair, and a high concentration of brown eumelanin results in brown hair; a high concentration of black eumelanin results in black hair.
Question of the Month:

This month’s question was submitted by Mitchell of Brooklyn, NY.

Q: Dear Professor, Which muscle in the human body is used the most during the day?

A: Eye muscles are the busiest muscles in the body. They are used about 100,000 times a day!