Quiz: Scratching the Surface: The Itching Quiz
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Scratching the Surface: The Itching Quiz
By: Staff
Image: refer to hsw

About This Quiz

With 20 square feet (2 square meters) of surface area covering the average human body, it's no surprise that skin can get itchy. And when hair, dust or other irritants make contact, there's a lot that has to happen before we respond with an almost reflexive scratch. Take our quiz to find out what goes on under the skin when it itches.

1.0 of 10
hint
About how many square feet of skin does the human body have?
10
20
30

The average human body is covered by about 20 square feet (2 square meters) of skin.

2.0 of 10
hint
What is the clinical name for itching?
itchmitis
hyperdermarosis
pruritus

The impulse to scratch a particular spot is known to scientists as "pruritus."

3.0 of 10
hint
When certain stimuli irritate the skin, they send signals to your cerebral cortex through which route?
spinal cord
arteries
cells

The spinal cord relays the information to your brain.

4.0 of 10
hint
How long does it take for your brain to receive the "itch" message?
less than a second
10 seconds
a minute

In a split second, receptors send a signal through fibers in the skin to the spinal cord and then to the brain.

5.0 of 10
hint
What did scientists once think itching was a form of?
cold sensations
heat sensations
pain

Experts used to believe that itching was a form of light pain.

6.0 of 10
hint
The impulse to scratch an itch is meant to achieve what?
to numb the source
to remove the source
to identify the source

Scratching an itch is intended to remove an irritant as soon as possible.

7.0 of 10
hint
Why does scratching temporarily stop itching?
Oils on hands and fingernails can reduce itching.
It interrupts the "itching" signal to the brain.
It removes the cause of the itch.

When you scratch, the signal being sent to your brain that you have an itch is interrupted.

8.0 of 10
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When you scratch, how many nerve endings do you activate?
more than covered by the irritant
less than covered by the irritant
the same amount as the irritant

By scratching an irritant, you trigger more nerve endings than it covers.

9.0 of 10
hint
What health conditions are known to cause itching?
allergies
infections
both

There are numerous medical causes of itching, including allergies, infections and many diseases.

10.0 of 10
hint
In addition to skin, what other organ is exposed to constant irritation?
the liver
the kidneys
none

Skin is the only organ that is constantly under the threat of irritants.

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