Introduction to Health ScienceIntroduction to Health ScienceSpecial SensesSpecial Senses

Vocabulary / Medical TerminologyVocabulary / Medical Terminology• Hearing – the sense by which sound is perceived.Hearing – the sense by which sound is perceived.• Vision – the act or power of sensing with the Vision – the act or power of sensing with the

eyes.eyes.• Taste – to distinguish flavor of using the mouth.Taste – to distinguish flavor of using the mouth.• Touch - to bring a bodily part into contact with, Touch - to bring a bodily part into contact with,

especially so as to perceive through the tactile especially so as to perceive through the tactile sensesense

• Opthalmo – eye - Blepharo – eyelidOpthalmo – eye - Blepharo – eyelid• Audio – hearingAudio – hearing - oto – ear - oto – ear• Glosso – toungeGlosso – tounge - ectasis – dilation - ectasis – dilation• -rraphy - suturing-rraphy - suturing

Description of the Special SensesDescription of the Special Senses• SmellSmell– Smell occurs when chemicals are detected by Smell occurs when chemicals are detected by

specialized cells in the nose resulting in nerve specialized cells in the nose resulting in nerve impulses which are sent to the brain for impulses which are sent to the brain for interpretation.interpretation.

NoseNose• In the upper part of the nasal cavity, are In the upper part of the nasal cavity, are

specialized nerve cells called specialized nerve cells called olfactory olfactory receptor cellsreceptor cells. The olfactory receptor cells . The olfactory receptor cells contain hair called cilia to which the dissolved contain hair called cilia to which the dissolved chemicals attach.chemicals attach.

• Nerve impulses are transmitted from the olfactory receptors Nerve impulses are transmitted from the olfactory receptors cells to the olfactory bulb, to the olfactory nerve to the brain cells to the olfactory bulb, to the olfactory nerve to the brain where the sense of smell is interpreted.where the sense of smell is interpreted.

NoseNose• Basic smells include Basic smells include – putrid (rotting food)putrid (rotting food)– pungent (spicy)pungent (spicy)– floral (flowers)floral (flowers)– ethereal (medicine smell)ethereal (medicine smell)– and mint.and mint.

TasteTaste• Taste occurs when chemicals are detected by Taste occurs when chemicals are detected by

specialized cells on the tongue resulting in specialized cells on the tongue resulting in nerve impulses which are sent to the brain for nerve impulses which are sent to the brain for interpretation.interpretation.

Mouth and TongueMouth and Tongue• The sense organs that detect dissolved The sense organs that detect dissolved

chemicals for the sense of taste are the taste chemicals for the sense of taste are the taste buds. Taste buds are located in the tongue buds. Taste buds are located in the tongue and throughout the mouth.and throughout the mouth.

• When the taste buds are stimulated by When the taste buds are stimulated by

chemicals, they generate nerve impulses chemicals, they generate nerve impulses which are sent to the brain for interpretation. which are sent to the brain for interpretation.

Mouth and TongueMouth and Tongue• There are five basic tastes, although they are There are five basic tastes, although they are

not limited to specific parts of the tongue: not limited to specific parts of the tongue: • sweet (sugars and carbohydrates)sweet (sugars and carbohydrates)• sour (acids)sour (acids)• salt (salt)salt (salt)• bitter (caffeine)bitter (caffeine)• umami (protein and amino acids)umami (protein and amino acids)

HearingHearing• Hearing involves the movement of sound Hearing involves the movement of sound

vibrations through the ear until they reach a vibrations through the ear until they reach a specialized region in the inner ear where specialized region in the inner ear where nerve impulses are generated. These nerve nerve impulses are generated. These nerve impulses travel to the brain where they are impulses travel to the brain where they are interpreted as sound. interpreted as sound.

Ear and HearingEar and Hearing• Outer EarOuter Ear• The outer ear is composed of cartilage The outer ear is composed of cartilage

covered with skin and hair.covered with skin and hair.• Captures the sound waves from the Captures the sound waves from the

environment.environment.

Auditory CanalAuditory Canal• Tube lined with hair and wax.Tube lined with hair and wax.• Assists in the passage of sound waves to the Assists in the passage of sound waves to the

middle ear.middle ear.• Provides protection for the ear as particles, Provides protection for the ear as particles,

debris, and dust are trapped by the hair and debris, and dust are trapped by the hair and the wax.the wax.

• Part of the outer earPart of the outer ear

Tympanic MembraneTympanic Membrane• Known as the eardrum, it is the structure that Known as the eardrum, it is the structure that

divides the outer ear with the middle ear.divides the outer ear with the middle ear.• It vibrates with the sound waves and passes It vibrates with the sound waves and passes

the vibrations to the middle ear bones.the vibrations to the middle ear bones.

Middle Ear and BonesMiddle Ear and Bones• Contains the middle ear bones (3) Contains the middle ear bones (3)

Malleus (hammer), Incus (anvil), Stapes Malleus (hammer), Incus (anvil), Stapes (stirrup)(stirrup)

• The middle ear bones continue the passage of The middle ear bones continue the passage of sound vibrations. They also amplify the sound vibrations. They also amplify the vibrations twenty times. vibrations twenty times.

• Eustachian Tube: is a tube that links the Eustachian Tube: is a tube that links the nasopharynx to the middle earnasopharynx to the middle ear

Inner Ear- hearingInner Ear- hearing• Cochlea:Cochlea:• is filled with a watery liquid, which moves in is filled with a watery liquid, which moves in

response to the vibrations coming from the middle response to the vibrations coming from the middle ear ear

• Organ of Corti :Organ of Corti :• The sound vibrations eventually reach a specialized The sound vibrations eventually reach a specialized

structure of the inner ear called the where nerve impulses structure of the inner ear called the where nerve impulses are generated. The impulses are transmitted to the brain are generated. The impulses are transmitted to the brain where they are interpreted.where they are interpreted.

Inner Ear- balanceInner Ear- balance• dynamic equilibrium dynamic equilibrium - - interprets balance when interprets balance when

one is movingone is moving– Semicircular CanalsSemicircular Canals

• static equilibrium static equilibrium - - interprets the position of the interprets the position of the head to maintain stability and posture when the head to maintain stability and posture when the head and body are not movinghead and body are not moving– VestibuleVestibule

Inner Ear-balanceInner Ear-balance• Semicircular Canals:Semicircular Canals:– A series of membrane-lined fluid-filled canalsA series of membrane-lined fluid-filled canals– Are the body's balance organs, detecting motion Are the body's balance organs, detecting motion

in the three perpendicular planes.in the three perpendicular planes.

• Vestibule:Vestibule:– Contains the saccule and utricle Contains the saccule and utricle – Work with the eyes to maintain postural balanceWork with the eyes to maintain postural balance

TouchTouch• Touch is the detection of various amounts of Touch is the detection of various amounts of

pressure by the skin. Nerve impulses are pressure by the skin. Nerve impulses are generated and sent to the brain for generated and sent to the brain for interpretation.interpretation.

SkinSkin• The skin contains several different types of nerve The skin contains several different types of nerve

receptors in the skin which are sensitive to deep receptors in the skin which are sensitive to deep pressure like poking or light touch.pressure like poking or light touch.

• All regions of the skin are sensitive to touch. The All regions of the skin are sensitive to touch. The greatest number of touch receptors are found in the greatest number of touch receptors are found in the fingers, toes, and face.fingers, toes, and face.

• Once the nerve impulses for touch are generated, Once the nerve impulses for touch are generated, they are sent to the brain for interpretation.they are sent to the brain for interpretation.

VisionVision• The sense organs that respond to light are the The sense organs that respond to light are the

eyes. eyes. • The light waves travel through the eyes until The light waves travel through the eyes until

the reach the back of the eye called the retina the reach the back of the eye called the retina where nerve impulses are transferred to the where nerve impulses are transferred to the optic nerve. optic nerve.

• The impulses travel to the brain where they The impulses travel to the brain where they are interpreted as visual images and provide are interpreted as visual images and provide much information about the external world.much information about the external world.

EyeEye• EyelidEyelid– Structures composed of skin, muscles, and lashesStructures composed of skin, muscles, and lashes– Protect the eye from foreign objects by the blink Protect the eye from foreign objects by the blink

reflex.reflex.– Moves tears along the surface of the eyeball.Moves tears along the surface of the eyeball.

ConjunctivaConjunctiva• Membrane lining the insides of the eyelids Membrane lining the insides of the eyelids

and eyeball.and eyeball.• Reduces friction during blinkingReduces friction during blinking

ScleraSclera• The white part of the eye.The white part of the eye.• Provides protection and shape to the eye.Provides protection and shape to the eye.

CorneaCornea• The clear window of the front part of the eye.The clear window of the front part of the eye.• Allows light waves to enter the eye.Allows light waves to enter the eye.• Helps to bend the light waves on the back of Helps to bend the light waves on the back of

the eye (retina)the eye (retina)

IrisIris• The colored portion of the eye which contains The colored portion of the eye which contains

two sets of muscles.two sets of muscles.• Regulates the size of the pupil.Regulates the size of the pupil.

PupilPupil• An opening in the center of the iris.An opening in the center of the iris.• Passage for light.Passage for light.

LensLens• Transparent structure located behind the iris Transparent structure located behind the iris

and pupil.and pupil.• Focuses light waves on to the retina.Focuses light waves on to the retina.

RetinaRetina• Most inner layer of the eyeball. Located under Most inner layer of the eyeball. Located under

the sclera.the sclera.• Contains the nerves that when stimulated by Contains the nerves that when stimulated by

light generate nerve impulses which are then light generate nerve impulses which are then sent to the brain for interpretation.sent to the brain for interpretation.

Disorders of the Special SensesDisorders of the Special Senses• ConjunctivitisConjunctivitis

– Conjunctivitis is the Conjunctivitis is the inflammation of the inflammation of the conjunctiva.conjunctiva.

– Can be caused by viruses, Can be caused by viruses, bacteria, fungi, and bacteria, fungi, and allergies. The most allergies. The most common cause is viral.common cause is viral.

– ””Pinkeye” is the common Pinkeye” is the common term for conjunctivitis.term for conjunctivitis.

Otitis MediaOtitis Media• Otitis media is a middle ear Otitis media is a middle ear

infection.infection.• Causes of otitis media include Causes of otitis media include

anything that causes the anything that causes the Eustachian (auditory) tubes to Eustachian (auditory) tubes to become blocked, inflamed or become blocked, inflamed or irritated. irritated.

• Examples include colds, sinus Examples include colds, sinus infections, allergies, tobacco infections, allergies, tobacco smoke or other irritants, babies smoke or other irritants, babies who spend a lot of time who spend a lot of time drinking on his or her back.drinking on his or her back.

TinnitusTinnitus• Tinnitus is the term used for any ear noise when Tinnitus is the term used for any ear noise when

there is not outside source for the sounds. there is not outside source for the sounds. • Is common. Most people have experienced it – and Is common. Most people have experienced it – and

it only lasts for a few minutes. it only lasts for a few minutes. • Causes are unknown but may be associated with an Causes are unknown but may be associated with an

ear infection, ear injury, and as a reaction to various ear infection, ear injury, and as a reaction to various drugs including alcohol, caffeine, antibiotics and drugs including alcohol, caffeine, antibiotics and aspirin. aspirin.

• Also known as ringing in the ears. Also known as ringing in the ears.

VertigoVertigo

• Also known as dizziness, Also known as dizziness, light headedness, or a light headedness, or a feeling that the room is feeling that the room is spinning or moving.spinning or moving.

• Occurs when:Occurs when:• there is not enough blood there is not enough blood

to the brain to the brain • changing the position of changing the position of

the head the head • a viral infection of the a viral infection of the

inner ear inner ear • or Meniere’s disease (an or Meniere’s disease (an

inner ear disease).inner ear disease).

MyopiaMyopia

• Nearsightedness; when a Nearsightedness; when a person sees near objects person sees near objects clearly and distant objects clearly and distant objects are blurred. are blurred.

• Occurs when the physical Occurs when the physical length of the eye is length of the eye is greater than the optical greater than the optical length. length.

• Symptoms include blurred Symptoms include blurred vision of distant objects, vision of distant objects, squinting, eyestrain, and squinting, eyestrain, and sometimes headaches.sometimes headaches.

HyperopiaHyperopia

• Farsightedness; when a person Farsightedness; when a person sees far objects clearly and sees far objects clearly and near objects are blurred.near objects are blurred.

• Occurs when the physical Occurs when the physical length of the eyeball is too length of the eyeball is too small or the small or the focusing focusing power of the lens is too weak.power of the lens is too weak.

• Symptoms include blurred Symptoms include blurred vision of close objects, eye vision of close objects, eye strain, aching eyes, and strain, aching eyes, and headaches while reading.headaches while reading.

Careers Associated With the Careers Associated With the Special SensesSpecial Senses• Speech-Language PathologistSpeech-Language Pathologist

– Speech-language pathologists, sometimes Speech-language pathologists, sometimes called called speech therapistsspeech therapists, assess, , assess, diagnose, treat, and help to prevent diagnose, treat, and help to prevent speech, language, cognitive-speech, language, cognitive-communication, voice, swallowing, communication, voice, swallowing, fluency, and other related disorders. fluency, and other related disorders.

– Education – Masters Degree Education – Masters Degree – Salary – National Average 65,000Salary – National Average 65,000

AudiologistAudiologist

• Audiologists work with people Audiologists work with people who have hearing, balance, and who have hearing, balance, and related ear problems. related ear problems.

• They examine individuals of all They examine individuals of all ages and identify those with ages and identify those with the symptoms of hearing loss the symptoms of hearing loss and other auditory, balance, and other auditory, balance, and related sensory and neural and related sensory and neural problems. problems.

• They then assess the nature They then assess the nature and extent of the problems and and extent of the problems and help the individuals manage help the individuals manage them. them.

• Education – Doctoral Education – Doctoral degree. Usually takes 4 degree. Usually takes 4 years of graduate school years of graduate school to earn an Au.D. to earn an Au.D.

• Salary - National average Salary - National average 63,00063,000

OptometristsOptometrists

• Optometrists provide most Optometrists provide most primary vision care. They primary vision care. They examine people’s eyes to examine people’s eyes to diagnose vision problems and diagnose vision problems and eye diseases, and they test eye diseases, and they test patients’ visual acuity, depth patients’ visual acuity, depth and color perception, and and color perception, and ability to focus and coordinate ability to focus and coordinate the eyes. the eyes.

• Optometrists prescribe Optometrists prescribe eyeglasses and contact lenses eyeglasses and contact lenses and provide vision therapy and and provide vision therapy and low-vision rehabilitation. low-vision rehabilitation. • Education – four year Education – four year

program at accredited program at accredited optometry school.optometry school.

• Salary - 96,000 Salary - 96,000