SensesDone by: Mariam Al-Khalifa

Class: 7C Science

Touch

How does the sense of “Touch” work?

The body has a number of receptors that monitor outside and inside conditions. One of those receptors is a pressure receptor, sensitive to touch. They are not distributed uniformly on your skin. They are most dense on your fingers and lips, least dense on your back. In addition, since there are more receptors than skin nerves that go to the brain, a number of these touch receptors feed into a single sensory nerve.

Why do we have the “Touch” sense?

Touch is one of the important senses, touch helps you guide yourself to a destination, or it makes you feel something . Like the sense can tell you if the things are hot or cold (Temperature) or sharp or if the water is reachable or deep and many more. Without this sense we could have serious injuries.

Smell

How does the sense of “Smell” work?

Example: A child is eating a packet of salt chipsChemicals in the crisps give them their smell. When you breath

in these chemicals enter your nose, in there they dissolve in liquid which moistens all the inside of the nose. The dissolved chemicals set up signals in the smell cells. These signals travel along nerves to the brain.

Why do we have the “Smell” sense?

Smell is also an important sense, because it can help you to know if what you are touching is gross, or what you are wearing is gross, it can tell you if you are smelling good, or it can tell you if the place you are in is gross or it’s smell is nice.

Taste

Experiment

How does the sense of “Taste” work?

• The surface in your tongue is rough because it contains your taste buds. When you eat or chew the food the chemical dissolves in the liquid in your tongue. It affects the taste buds which send messages to the brain.

Diagram

Why do we have the “Taste” sense?

• We have the sense of taste for a reason , its because without taste we wouldn’t know what we are eating, whether it is healthy or not.

Eyes

How does the sense of “Eyes” work?

• When light rays pass through your pupil, the muscle called the iris (colored ring) makes the size of the pupil change depending on the amount of light that's available. Likewise, if there is very little light available, the pupil will enlarge to let in as many light rays as it can. Just behind the pupil is the lens and it focuses the image through a jelly-like substance called the vitreous humor onto the back surface of the eyeball, called the retina.

• The retina, which is the size of your thumbnail, is filled with approximately 150 million light-sensitive cells called rods and cones.

• Cones on the other hand, identify color and work best in bright light. Both of these types of cells then send the information to the brain by way of the optic nerve.

Why do we have the “Eyes” sense?

• From the moment you wake up in the morning to the time you go to sleep at night, your eyes are acting like a video camera. Everything you look at is then sent to your brain for processing and storage much like a video cassette.

• We use eyes to recognize and discover objects without them we would be struggling a lot in our life. Eyes are very important because without them you won’t really live a normal life, you would be struggling with medication a lot.

Sound

How does the sense of “Sound” work?

• Hearing begins with the ears, which receive sounds and send them to the auditory cortex, near the back of the brain, for processing. The primary instrument for sound gathering in the ear is the eardrum, or tympanic membrane, which separates the outer ear from the middle ear. The eardrum passes along sound vibrations to the ossicles, the three smallest bones in the human body, when then divert it to the fluid-filled, labyrinth-like structure in the inner ear called the cochlea, where the true hearing organs reside.

Why do we have the “Sound” sense?

• Without sound we would be struggling during our life. We wouldn’t hear what people talk about and we would have to give hand signals so we can communicate with other people. We may have accidents because if you drive you may not hear the car behind you trying to give you signals so that would lead to a accident.

Did you know?

• You probably have about 20,000,000 smell cells but 9,000 taste buds.

• You can get used to a smell, after sometime, your smell cells stop sending messages to the brain.

• Our sense of taste is greatly influenced by our sense of smell.

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