CONTENTS

PERCEPTION & CONPETION

SIGHT

TASTE

TOUCH

SMELL

HEARING

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Sight

Sound

Smell

Taste

Touch

Perception Conception

The ability to see, hear, or become aware of something through the senses.

PERCEPTION

Something conceived in the mind, a concept, plan, design, idea, or thought.

CONCEPTION

2The senses shown on the brain aren’t accurate.

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SIGHT

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Sight or vision is the ability of the eyes to focus and detect images of visible light and Photoreceptors in the retina.The retina of each eye generates electrical nerve impulses for Varying colours, hues and brightness

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. This is a very simplified explanation, but as you read on, you will discover why the sense of sight is actually considered the most complex of the five senses.How Your Eyes WorkTake a moment to locate an object around you. Do you know how you are able to see it? Would you believe that what you are actually seeing are beams of light bouncing off of the object and into your eyes? It is hard to believe, but it is true. The light rays enter the eye through the cornea, which is a thick, transparent protective layer on the surface of your eye. Then the light rays pass through the pupil (the dark circle in the center of your eye) and into the lens.

DefinitionRetina: A delicate, multilayered, light-sensitive membrane lining the inner eyeball and connected by the optic nerve to the brain.Vitreous: Of, relating to, resembling, or having the nature of glass; glassysclera: The tough white fibrous outer envelope of tissue covering all of the eyeball except the cornea. Also called sclerotic, sclerotic coat.Conjunctiva: The mucous membrane that lines the inner surface of the eyelid and the exposed surface of the eyeball.Aqueous: Relating to, similar to, containing, or dissolved in water; watery.Pupil: The apparently black circular opening in the center of the iris of the eye, through which light passes to the retina.Cornea: The transparent convex anterior portion of the outer fibrous coat of the eyeball that covers the iris and the pupil and is continuous with the sclera.Iris: The pigmented, round, contractile membrane of the eye, suspended between the cornea and lens and perforated by the pupil. It regulates the amount of light entering the eye.Lens: Biconvex transparent body situated behind the iris in the eye; its role (along with the cornea) is to focuses light on the retina.

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TASTE

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Tasting commonly called Gustation is a capability to detect the taste of substances like food, certain minerals and poisons.

Have you ever thought about why foods taste different? It’s really quite amazing. Your tongue and the roof of your mouth are covered with thousands of tiny taste buds. When you eat something, the saliva in your mouth helps break down your food. This causes the receptor cells located in your tastes buds to send messages through sensory nerves to your brain. Your brain then tells you what flavors you are tasting.

Taste buds probably play the most important part in helping you enjoy the many flavors of food. Your taste buds can recognize four basic kinds of tastes: sweet, salty, sour, and bitter. The salty/sweet taste buds are located near the front of your tongue; the sour taste buds line the sides of your tongue; and the bitter taste buds are found at the very back of your tongue.

Everyone’s tastes are different. In fact, your tastes will change as you get older. When you were a baby, you had taste buds, not only on your tongue, but on the sides and roof of your mouth. This means you were very sensitive to different foods. As you grew, the taste buds began to disappear from the sides and roof of your mouth, leaving taste buds mostly on your tongue. As you get older, your taste buds will become even less sensitive, so you will be more likely to eat foods that you thought were too strong as a child.

DefinitionLingual Tonsil: A mass of lymphoid follicles near the root of the tongue. Each follicle forms a rounded eminence containing a small opening leading into a funnel-shaped cavity surrounded by lymphoid tissue. Palatine Tonsil: One of a pair of almond-shaped masses of lymphoid tissue between the palatoglossal and palatopharyngeal arches on each side of the fauces. They are covered with mucous membrane and contain numerous lymph follicles and various crypts.Foliate Papillae: A series of nipplelike processes that occur in folds along the lateral margins and in the front of the palatoglossus muscle of the tongue.Filiform Papillae: Any of numerous elongated conical projections on the back of the tongue.Fungiform Papillae: Any of the numerous projections that are arranged in several transverse folds on the lateral margins of the tongue just in front of the palatoglossus muscle.Circumvallate Papillae: The circumvallate papillae (or vallate papillae) are dome-shaped structures on the human tongue that vary in number from eight to twelve.

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TOUCH

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Touch or Somato sensory is a perception generates from anticipation of the neural receptors generally in the skin including hair follicles, tongue, throat and mucosa. receptors respond to the pressure according neural.

While your other four senses (sight, hearing, smell, and taste) are located in specific parts of the body, your sense of touch is found all over. This is because your sense of touch originates in the bottom layer of your skin called the dermis. The dermis is filled with many tiny nerve endings which give you information about the things with which your body comes in contact. They do this by carrying the information to the spinal cord, which sends messages to the brain where the feeling is registered The nerve endings in your skin can tell you if something is hot or cold. They can also feel if something is hurting you. Your body has about twenty differnt types of nerve endings that all send messages to your brain. However, the most common receptors are heat, cold, pain, and pressure or touch receptors. Pain receptors are probably the most important for your safety because they can protect you by warning your brain that your body is hurt!

Some areas of the body are more sensitive than others because they have more nerve endings. Have you ever bitten your tongue and wondered why it hurt so much? It is because the sides of your tongue have a lot of nerve endings that are very sensitive to pain. However, your tongue is not as good at sensing hot or cold. That is why it is easy to burn your mouth when you eat something really hot. Your fingertips are also very sensitive. For example, people who are blind use their fingertips to read Braille by feeling the patterns of raised dots on their paper.

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SMELL

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Smell is a chemical sense that detects odor; odor is detected by binding a particular molecule feature to odor receptors. Food, perfume, alcohol, smoke, chemicals etc.

Have you ever wondered what you smell when you “smell the roses” in the spring time? What makes a smell is something that is too small to see with your eyeball alone. It is even too small to be seen with a microscope! What you smell are tiny things called odor particles. Millions of them are floating around waiting to be sniffed by your nose!

You smell these odors through your nose which is almost like a huge cave built to smell, moisten, and filter the air you breathe. As you breathe in, the air enters through your nostrils which contain tiny little hairs that filter all kinds of things trying to enter your nose, even bugs! These little hairs are called cilia and you can pretend that they sweep all the dirt out of the nasal cavity, which is the big place the air passes through on it’s way to the lungs. After passing through the nasal cavity, the air passes through a thick layer of mucous to the olfactory bulb. There the smells are recognized because each smell molecule fits into a nerve cell like a lock and key. Then the cells send signals along your olfactory nerve to the brain. At the brain, they are interpreted as those sweet smelling flowers or that moldy cheese.

Our sense of smell is connected really well to our memory. For instance, the smell of popcorn can remind you of being at the movies with a friend or the smell of tar can remind you of riding in a car to the beach.

DefinitionOlfactory Bulb: one of two enlargments at the terminus of the olfactory nerve at the base of the brain just above the nasal cavities.Nasal Conchae: A separate curved bony plate that is the largest of the three and separates the inferior and middle meatuses of the nose.

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HEARING

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Hearing is a mechanical sense that detects sound vibrations and perceives them through a medium air e.g.: Speech, crying, song etc.

Like your other sense organs, your ears are extremely well-designed. In fact, they serve two very important purposes. Do you know what they are? You were probably able to figure out that your ears help you to hear sounds, but what you probably did not know is that your ears also help you to keep your balance.

How You Hear?When an object makes a noise, it sends vibrations (better known as sound waves) speeding through the air. These vibrations are then funneled into your ear canal by your outer ear. As the vibrations move into your middle ear, they hit your eardrum and cause it to vibrate as well. This sets off a chain reaction of vibrations. Your eardrum, which is smaller and thinner than the nail on your pinky finger, vibrates the three smallest bones in your body: first, the hammer, then the anvil, and finally, the stirrup. The stirrup passes the vibrations into a coiled tube in the inner ear called the cochlea.

How You Keep Your Balance?Near the top of the cochlea are three loops called the semi-circular canals. The canals are full of liquid also. When you move your head, the liquid moves. It pushes against hairlike nerve endings, which send messages to your brain. From these messages, your brain can tell whether or how your body is moving.

If you have ever felt dizzy after having spun around on a carnival ride, it was probably because the liquid inside the semicircular canals swirled around inside your ears. This makes the hairs of the sensory cells bend in all different directions, so the cells’ signals confuse your brain.

DefinitionLabyrith: The portion of the ear located within the temporal bone that is involved in both hearing and balance and includes the semicircular canals, vestibule, and cochlea.Cochlea: A spiral-shaped cavity of the inner ear that resembles a snail shell and contains nerve endings essential for hearing.Ear Drum: The thin, semitransparent, oval-shaped membrane that separates the middle ear from the external ear. Also called tympanic membrane, tympanum.Ossicles: a small bone, especially one of those in the middle ear, which transmit vibrations from the tympanic membrane to the oval window.

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