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Q: Sites with interesting, fun facts about the human senses ( Answered 5 out of 5 stars,   1 Comment )
Subject: Sites with interesting, fun facts about the human senses
Category: Science > Biology
Asked by: somethingcreative-ga
List Price: $10.00
Posted: 25 Jul 2004 12:17 PDT
Expires: 24 Aug 2004 12:17 PDT
Question ID: 378861
I'm looking for interesting/fun tidbits and information about the
human sensory system (hearing, smell, taste, touch, sight). Memorable
anecdotes and surprising statistics on our senses would be appreciated
as well.
Subject: Re: Sites with interesting, fun facts about the human senses
Answered By: bobbie7-ga on 25 Jul 2004 14:48 PDT
Rated:5 out of 5 stars
Below you will find the results of my research regarding fun facts
about the human senses.

Sense of Taste

?We have almost 10,000 taste buds inside our mouths; even on the roofs
of our mouths.

Insects have the most highly developed sense of taste. They have taste
organs on their feet, antennae, and mouthparts.

Fish can taste with their fins and tail as well as their mouth. 

In general, girls have more tastebuds than boys. 

Taste is the weakest of the five senses.?

Think Quest

?Total number of human taste buds (tongue, palate, cheeks) = 10,000

Number of taste buds on the tongue = 9,000

Height of taste bud = 50-100 microns 

Diameter of taste bud = 30-60 microns 

Number of receptors on each taste bud = 50-150 

Diameter of taste receptor = 10 micron

Diameter of taste fiber = less than 4 micron

Taste threshold for quinine sulfate = 3.376 mg/liter water?

UW Faculty

There are four basic tastes: sweet, salty, sour and bitter:
UW Faculty

?The surface of human tongues are covered with thousands of tiny bumps
called papillae! Your taste buds lie at the base and on the sides of
the papillae.

Food dosen't taste as good, when a person has a cold and nose is blocked.

Human sense of smell affects sense of taste! The brain interprets
signals from the nose and tongue.

Most people can tell the difference between 10000 different odours!?

Taste Bud Trivia

Fun facts about the sense of taste...

?Insects have the most highly developed sense of taste. They have
taste organs on their feet, antennae, and mouthparts.?
?Fish can taste with their fins and tail as well as their mouth.?
?In general, girls have more tastebuds than boys do.?

?As we get older the olfactory bulb in the brain responsible for
processing smell becomes smaller.?

Supermarket Guru


- ?The tongue has 9,000 taste buds, each having 10-15 receptacles that
send messages to the brain.

-Over a 12-day period, your body generates a whole new set of taste
buds. This process continues until you reach your 70s and 80s.

- Smoking, alcohol, caffeine, spicy and hot foods, onion and garlic
dull taste buds. It takes 24 hours for taste buds to cleanse
themselves after being exposed to these substances.

- Taste buds are most sensitive right after a night's sleep.?

Sense of Sight

- ?Most people blink every 2-10 seconds. 

- A newborn baby sees the world upside down because it takes some time
for the baby's brain to learn to turn the picture right-side up.

- One in every twelve males is color blind.
- Each time you blink, you shut your eyes for 0.3 seconds, which means
your eyes are closed at least 30 minutes a day just from blinking.

-  If you only had one eye, everything would appear two-dimensional.
(This does not work just by closing one eye.)
-  Owls can see a mouse moving over 150 feet away with light no
brighter than a candle.

-  The reason cat's and dog's eyes glow at night is because of silver
mirrors in the back of their eyes called the tapetum. This makes it
easier for them to see at night.

- An ostrich has eyes that are two inches across. Each eye weighs more
than the brain.

- A chameleon's eyes can look in opposite directions at the same time. ?

Think Quest

Number of fibers in human optic nerve = 1,200,000

Number of fibers in cat optic nerve = 119,000

Number of fibers in albino rat optic nerve = 74,800

Length of optic nerve = 50 mm?

UW Faculty

?Length of eyeball = 24.5 mm 
Volume of eyeball = 5.5 cm3
Weight of eyeball = 7.5 g
Average time between blinks = 2.8 seconds
Average duration of a single blink = 0.1-0.4 seconds 
Thickness of cornea = 0.54 mm in center; 0.65 in periphery
Diameter of cornea = 11.5 mm
Thickness of lens = 4 mm
Diameter of lens = 9 mm
Composition of lens = 65% water; 35% protein?

?Number of fibers in optic nerve = 1,200,000?

?Wavelength of visible light (human) = 400-700 nm?

?Area of retina = 2,500 mm2
Thickness of retina = 120 microns (ranges from 100 to 230 microns)?

UW Faculty

?The eye muscles are the most active muscles in the whole body  

Eyes are composed of more than two million working parts  

The eye can process 36,000 bits of information every hour  

Eyes can instantaneously set in motion hundreds of muscles and organs
in your body

A normal life-span will bring you almost 24 million images of the
world around you ?

?The external muscles that move the eyes are the strongest muscles in
the human body for the job that they have to do. They are 100 times
more powerful than they need be.?
?The eye is the only part of the human body that can function at 100%
ability at any moment, day or night?
?The cornea is approximately the size and thickness of a dime?  
?A blink of an eye lasts about one tenth of a second ? 
?The average person blinks their eyes about 11,500 times per day or
about 4.2 million times per year.?
?There are only two tissues in your body that do not receive oxygen
from your blood ? corneas and nails?

Bausch & Lomb


?An owl can see a mouse moving over 150 feet away with light no
brighter than a candle!?

?A cat's eyes glow in the dark because of special silvery "mirrors"
that reflect light, making it much easier for them to see in the dark.

?So-called "color-blindness," in which colors such as green and red
are hard to distinguish, affects about 1 in 30 people -- and many
times more men than women!?

Discovery Communications Inc

Read about cat eye trivia here:

Sense of Smell

?Humans have seven primary odors that help them determine objects.
Listed below are the seven odors?

Odor              Example
Camphoric        Mothballs
Musky            Perfume/Aftershave
Roses            Floral 
Pepperminty      Mint Gum 
Etheral          Dry Cleaning Fluid 
Pungent          Vinegar 
Putrid           Rotten Eggs 

?Humans use insect warning chemicals, called pheromones, to keep away
pesky insects!

People who cannot smell have a condition called Anosmia.?

?If your nose is at its best, you can tell the difference between
4000-10,000 smells!

As you get older, your sense of smell gets worse. Children are more
likely to have better senses of smell than their parents or

Dogs have 1 million smell cells per nostril and their smell cells are
100 times larger than humans! ?

Think Quest

?Number of human olfactory receptor cells = 40 million

Number of rabbit olfactory receptor cells = 100 million

Number of dog olfactory receptor cells = 1 billion?

?Surface area of olfactory epithelium (contains olfactory receptor
cells) in humans = 10 cm2
Area of olfactory epithelium in some dogs = 170 cm2 (
Area of olfactory epithelium in cats = 21 cm2 

UW Faculty

Smell Facts

- ?Taste is 75% smell
- Moths can smell a single molecule
- Dogs can distinguish non-identical twins by smell, but not identical ones.?

?Memory for smell is long lasting.?

Sense of Touch

?You have more pain nerve endings than any other type.
The least sensitive part of your body is the middle of your back. 
The most sensitive areas of your body are your hands, lips, face,
neck, tongue, fingertips and feet.

Shivering is a way your body has of trying to get warmer. 

There are about 100 touch receptors in each of your fingertips. 

Rattlesnakes use their skin to feel the body heat of other animals.?

Think Quest

?Weight of skin (adult human) = 9 lb.(4-5 kg) 

Surface area of skin (adult human) = 3,000 in2 (~1.8 m2)

Number of tactile receptors in the hand = 17,000

Number of nerve endings in hand = 1,300 per in2
Thermal pain threshold = 45oC?

UW Faculty

Sense of Hearing

?Babies can get earaches because of milk backing up in the Eustachian
tube, which causes bacteria to grow and may cause hearing problems
later in life.

When you go up to high elevations, the change in pressure causes your ears to pop. 

Children have more sensitive ears than adults. They can recognize a
wider variety of noises.

Dolphins have the best sense of hearing among animals. They are able
to hear 14 times better than humans.

Animals hear more sounds than humans. 

An earache is caused by too much fluid putting pressure on your
eardrum. Earaches are often the result of an infection, allergies or a

Think Quest

?Number of fibers in auditory nerve = 28,000-30,000

Length of auditory nerve = 2.5 cm

Hearing Range (young adult human) = 20 to 20,000 Hz

Hearing Range (elderly human) = 50 to 8,000 Hz 

Hearing Range (rat) = 1,000 to 50,000 Hz

Hearing Range (cat) = 100 to 60,000 Hz

Most sensitive range of human hearing = 1,000-4,000 Hz?

?Auditory Pain Threshold = 130 db
Threshold for hearing damage = 90 db for an extended period of time?

UW Faculty

See Miscellaneous Hearing Trivia at the following link:
 Questions about Miscellaneous Hearing Trivia from real people and
answered by audiologists.

Read amazing facts and trivia about the senses of certain animals here:

Search criteria:
human sensory system +trivia
senses facts OR trivia
sight facts OR trivia
vision facts OR trivia
taste facts OR trivia
smell facts OR trivia
touch facts OR trivia
hearing facts OR trivia
audition facts OR trivia

I hope you find this information helpful!

Best regards,
somethingcreative-ga rated this answer:5 out of 5 stars
Very well fleshed-out and satisfactory answer.

Subject: Re: Sites with interesting, fun facts about the human senses
From: j_philipp-ga on 30 Jul 2004 04:54 PDT
Great extensive answer and fun read!

I would like to add "A newborn baby sees the world upside down" is a
(very popular) myth. Steven Pinker (Department of Brain and Cognitive
Sciences, MIT) in "How the Mind Works" explains:

"Another comment is that the computational theory of mind, explicitly
or not, has set the agenda for brain science for decades. An old
example from introductory neuroscience classes describes the naive
person who asks, "Since the image on the retina is upside-down but we
see the world right-side up, is there some part of the brain that
turns the image right-side up?" We all realize that this question
rests on a fallacy, that there is no such process in the brain, and
that there doesn't need to be any such process. Why is it a fallacy?
Because the orientation of the image on the retina makes no difference
to how the brain processes information. Since information-processing
is the relevant aspect of what goes on in the brain, the orientation
on the retina?and, for that matter, on the visual cortex?is
irrelevant; that is why the above is a pseudoquestion."

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