Human Sensory Organs
There are a total of five sensory organs that help us in hearing, seeing, feeling, tasting, and smelling. They are the eyes, ears, nose, tongue, and skin, and all these five organs are vital for us to survive.
They all play an important role in the functions that we carry out regularly. They contribute to crucial actions needed for living. Eating, breathing, smelling, hearing, and seeing are all essential for life.
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Without eating, we cannot survive.
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Without breathing, lack of oxygen will be fatal.
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Without feeling, smelling, or seeing, life would become difficult, and we would struggle to stay safe from harmful things around us.
Five Sensory Organs
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Eyes – help us to see things around us.
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Nose – helps us smell different fragrances.
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Tongue – helps us taste food or other substances.
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Skin – helps us feel sensations and produces sweat.
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Ears – helps us hear noises or speech.
The Eye – The Organ of Vision
Most living organisms have eyes for vision. They allow organisms to visualize things.
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Discovered by Roger Bacon.
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Eyes detect light waves and convert them into electrochemical impulses that are sent to the brain.
Seven Significant Parts of the Eye
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Sclera – white part of the eye that protects the eyeball.
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Cornea – covers the iris and pupil.
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Iris – controls the amount of light entering the eye.
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Pupil – black part controlling light intake.
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Lens – focuses light onto the retina.
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Retina – detects light and converts it into electrical impulses sent to the brain.
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Optic nerves – transmit visual information to the brain.
Layers of the Eye
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Outer layer (fibrous tunic): sclera and cornea
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Middle layer (vascular tunic): uvea
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Inner layer (neural tunic): retina
Accommodation
Accommodation is the process of changing the shape of the lens to focus on distant or nearby objects.
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For close objects, the lens becomes thicker, refracting light rays more strongly.
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This allows the focal length of the eye to change and the image to form clearly on the retina.
Ear – Hearing and Equilibrium
The ears help us hear and listen to sounds around us.
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Three parts: outer ear, middle ear, inner ear
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Three small bones: malleus, incus, stapes
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The stapes is the smallest bone in the human body.
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