Docstoc

Chapter 10 Special Senses

Document Sample
Chapter 10 Special Senses Powered By Docstoc
					Chapter 10 Special Senses

   HSTE II Applications of Therapeutic
                Services
Special Senses

  Organs   and Receptors Associated With:
   –   Touch (Sensory Receptors)
   –   Vision
   –   Hearing
   –   Smell
   –   Taste
Distance Senses

  Sight

  Hearing

  Smell



  Why?
   – They bring information from far away.
Direct Contact Senses

  Touch

  Taste
         Only reveal information from direct contact
Functions of the Special Senses


 Receive   Stimuli From Sensor Receptors
  –   Eye
  –   Ear
  –   Nose
  –   Tongue
 Transmit  Impulses to the Brain for
  Interpretation
Sensory Receptors

            by Changes in the
  Stimulated
   Environment
  Include:
   –   Touch
   –   Pain
   –   Temperature
   –   Pressure (Proprioceptors)
Found All Over the Body


  Skin

  Connective   Tissue
  Muscle
Special Sensory Receptors


  Taste  Buds of the Tongue
  Special Cells of the Nose

  Retina of the Eye

  Special Cells of the Inner Ear (organ of
   Corti)
When Sense Organ Stimulated

  Impulse   Travels
   – Along Nerve Pathways
   – To the Brain
   – Where it is Registered in a Certain Area
Sensation Takes Place in Brain

  But   is Mentally Referred Back
   – To the Sense Organ
  This   Process is Called
   – Projection of the Sensation
Review

  What  are the 5 special senses?
  Which of the 3 of the 5 are distance
   senses?
  Information from touch and taste can be
   revealed only by ____________.
  What are the two functions of special
   senses?
Answers

  Touch,   Vision, Hearing, Smell, and
   Taste
  Sight, Hearing, Smell

  Direct Contact with an Object

  Receive Stimuli and Transmit Impulses
   to the Brain for Interpretation
Choroid Coat: Middle Layer of the
          Eye & Iris


   Contains Blood Vessels
    – To nourish the eye
   Non-reflective pigment
    – To render it dark (deep, red-purple) to prevent
      light reflection
   Circular opening in Choroid coat called
    – The Pupil
   Colored, muscular layer surrounds the pupil
    called
    – The Iris or colored part of the eye
Eye Color

  Related to number and size of Melanin
  The Iris can be
     –   Blue (little melanin)
     –   Green (little more)
     –   Gray (little more)
     –   Brown (Still more)
     –   Black (the most)
     –   Pink (Absence of Melanin, Albinism)
             Choroid blood vessels show through
Iris

  Two sets of antagonistic smooth
   muscles
       – Sphincter Pupillae Muscle
       – Dilator Pupillae Muscle
  Intrinsic    Muscles
       – Help iris to control amounts of light
         entering the pupil
Iris

  Close       to object or stimulated by bright
   light
       – Sphincter Pupillae Muscle contracts
             Pupil smaller
  Distant       object, stimulated by dim light
       – Dilator Pupillae Muscle Contracts
             Pupil larger
Table 10-1 Extrinsic & Intrinsic
         Eye Muscles

Eye Muscle           Function

A.   Extrinsic

1. Superior Rectus   Rolls eyeball upward

2. Inferior Rectus   Rolls eyeball
                     downward
3. Lateral Rectus    Rolls Eyeball laterally
Extrinsic

 4. Medial Rectus      Rolls Eyeball Medially

 5. Superior Oblique   Rolls Eyeball on its
                       axis, moves cornea
                       downward and laterally
 6. Inferior Oblique   Rolls eyeball on its
                       axis, moves cornea
                       upward and laterally
 B. Intrinsic
Intrinsic

 1. Sphincter Pupillae   Constricts Pupil




 2. Dilator Pupillae     Dilates Pupil
Lens & Related Structures

  Lens
   – Crystalline structure
       Located behind the iris and pupil
       Concentric layers of Fibers

       And Crystal-Clear Proteins in Solution

   – Purpose
         Focus images on the retina
Lens

  Elastic,Disc-shaped structure with
   anterior and posterior convex surfaces
    – Thus forms a biconvex lens
    – This curvature altars with age
  Lens   held in place by
    – Suspensory Ligaments
    – From the Ciliary Body of the
    – Choroid Body
Lens

  Situated    Between
   – Anterior & Posterior Chambers
   – Anterior
          Filled with Watery Fluid Called
             – Aqueous Humor
   – Posterior
        Filled with Jellylike Substance
        Maintains the Eyeball’s Shape
Lens

  The   muscle controls the shape of the
  lens
   – For near and far distances
   – Process Called
   – Accommodation
Retina

  Innermost Layer of the Eye ( 3rd Coat)
  Does not extend around front portion of
   the eye
    – Light-Sensitive Layer
        Light Rays From an Object Form an Image
        Then Travels via Optic Nerve

        Occipital Lobe of Cerebral Cortex
Retina

    Contains Pigment & Specialized Cells
     – Rods
     – Cones
    Rod Cells
     – Sensitive to Dim Light
    Cone Cells
     – Sensitive to Bright Light
     – Responsible for Color Vision
Optic Disc and Fovea

  Looking    Through Ophthalmoscope
   – Yellow Disc – Macula Lutea
         Within Fovea Centralis
           – Contains the Cones
   – Pale Disc
       Optic Disc or Blind Spot
       Nerve Fibers join to form nerve

       No Rods or cones/NO Vision at this spot

       Fig. 10-6 Test for Blind Spot
Pathway of Vision

  Images of Light⇒Cornea⇒Pupil⇒
  Lens⇒Where the light rays are
   bent or refracted⇒Retina⇒Rods &
   Cones⇒Optic Nerve⇒Optic
   Chiasma(Where the 2 optic nerves
   cross)⇒Optic Tracts⇒Occipital
   Lobe of Brain for Interpretation
  Fig. 10-7
Eye Disorders

    Conjunctivitis – “Pink Eye”
      – Inflammation of the Conjunctival Membranes
    S/SX
      – Redness, Pain, Swelling, Discharge of Mucous
    Begins
      – In one eye and can spread rapidly
    Very Contagious
    Tx
      – Eye Washes
      – Antibiotic Drug Therapy
Next 4 Eye Disorders Occur with
            Aging

 Glaucoma

 Cataracts

 MacularDegeneration
 Detached Retina
Glaucoma

    Excessive Intraocular          S/Sx
     Pressure                        – Gradual Onset
    Results In                      – Mild aching
      – Destruction of               – Loss of peripheral
        Retina/Atrophy Optic           Vision
        Nerve                        – Halo Around light
    Cause:                         Factor- Aging
      – Overproduction of            – Test annually after 40
        Aqueous Humor and/or         – Tonometry
        Obstruction of outflow
                                    Tx – Miotic Drugs
                                     – Constrict Pupil
                                     – Surgery
99599898
2
1




           Cataracts

             Lens    gradually becomes Cloudy
              –    People over 70
              –    Painless
              –    Gradual Blurring of Vision
              –    Loss of Vision
             Tx   – Laser Surgery/Surgical Removal
              – Lens
              – Intraocular Lens Implant Behind Cornea
Macular Degeneration

    Two Types
     – Wet/Dry
    Wet
     – New blood vessels grow behind the macula
              Leak, bleed, Distort Shape
     – Tx
              Avastin drugs
              Injected right in eye ball- Inhibits growth
              Laser Treatment
     – Can still maintain function with vision losses with
              Low-Vision Aids
Macular Degeneration

  Dry
   – Main Defect
          Gradual thinning of Retina
          Slow Progression

   – NO KNOWN TX
   – Central Vision Greatly Reduced
   – But not Blind
Detached Retina

    May also occur from
      – Traumatic Accident in a Younger Person
    Vitreous Fluid Contracts
      – Pulls on Retina
      – Causes a Tear
    S/SX
      – Loss of Peripheral Vision
      – Then Loss of Central Vision
    TX
      – Early Detection
      – Laser
      – Freezing
    ***NOTE – Get your eyes tested Annually
Diabetic Retinopathy

  Leading Cause of Blindness in USA
  Diabetes
     – Changes in Blood Vessels in Retina
     – Swell, leak, Abnormal
  No Sx early phase – Need eye Exam
  See Red Spots later

  Tx
     – Laser Surgery
Sty (Hordeolum)

  Tiny   abscess at base of eyelash
   – Sx – Red, painful, Swollen
         Due to Inflammation of Sebaceous Gland on
          eyelid
   – Tx
         Warm, Wet Compresses
           – Relieve pain
           – Promote Drainage
Eye Injuries

    Fragments/Particles
     – DO NOT ATTEMPT TO REMOVE
     – Patch both eyes seek Med. Attn.
    Cornea Abrasions
     – Accident/Irritation
     – If severe
             May need Corneal Transplants
             Not rejected becaues Cornea are Avascular
    Chemicals in Eyes
     – Flush Immediately
     – 15 min.
     – Seek Med. Attn.
Vision Defects

    Eye Strain/Dry Eyes
     – Common Cause
              Too Much Computer Use
    Sx
     – Burning, tightness, Sharp/Dull Pain, Watery, blurry vision,
       HA
    Tx
     –    Reposition Monitor
     –    Glare Screen
     –    Dark Clothing
     –    Window shades
     –    Where Corrective Lenses if needed
Vision Defects Continued

  Night Blindness         Color Blindness
  Rod Cells Affected       – Inability to
                              Distinguish colors
                            – Cones affected
                            – Hereditary
                              Characteristic
Visions Defects

    Presbyopia                Hyperopia
     – Lenses lose their        (Farsightedness)
       elasticity as we age    Can see Far but not
     – Occurs after 40          Near
     – Difficulty Focusing        – Eyeball Shorter
     – Corrective lenses            than normal
            Bifocals             – Convex lenses
                                    correct
Vision Defects

    Myopia (Nearsightedness)            Amblyopia
    Can see Near but not far              – Dimness of Vision
    Focal Point in front of Retina      Astigmatism
    Eyeball Elongated                     – Irregular curvature of lens or
                                             cornea
      – Longer than normal
                                                    Blurred Vision
      – Concave lenses correct                      Eye Strain
    Photo Refractive Keratectomy        Special Prescription
      – Laser Surgery                     Eyeglasses
                                         Diplopia – Blurred Vision
                                         Strabismus – Cross Eyes
                                           – Muscles do not coordinate
                                             Muscle movement
                                           – Children
                                         Exorcises or Surgery
The Ear

  Special   Sense Organ
   – Picks up Sound Waves
   – Sends the to the Auditory Center
   – Located in Temporal Area
  Receptor    for Hearing
   – Delicate organ of Corti
         Located in Cochlea of inner ear
Ear & Equilibrium

  Receptors   in Inner Ear
   – Send message to the Cerebellum
       About Head Position
       Helps maintain Balance
Three Parts of the Ear

  Outer/External   Ear
  Middle Ear
  Inner Ear
                   The Ear

 Outer   Ear
  – Pinna/Auricle
  – Collects Sound Waves Direct to
      Auditory Canal
      Canal lined with
          – Sebaceous/Calumnious Glands
          – Secrete Wax-like or oily Substance
              • Cerumen
              • Protects the Ear
Tympanic Membrane

  Separates   Outer Ear from
   – Middle ear
   – Directs Sound Waves
Middle Ear

    Cavity in Temporal Bone
    Connects with the Pharynx (Throat)
     – By Eustachian Tube
     – Equalizes Pressure on both sides of ear drum/tympanic
       membrane with outside atmosphere
    Chain of 3 Tiny Bones
     – Hammer (Malleus)
     – Anvil (Incus)
     – Stirrup (Stapes)
            Transmit Sound Waves
            Drum to Inner Ear
Inner Ear

    Several Membrane-Lined                       Cochlear Duct Contains
     Channels                                       – Delicate cells of the organ of
      – Deep in temporal bone                         Corti
    Special Organ of Hearing –                              Hair-like cells pick up
                                                              vibrations
     Spiral Shaped                                           Transmit to auditory nerve
      – Cochlea                                              To the Brain
               Contains Cochlear Duct
           
                  –   Filled with fluid that
                                                  Semi-circular Canals
                      vibrates                      – Contain Liquid
                  –   When hit by sound             – Delicate Hair-like Cells
                      waves from the stirrup
                      bone                          – Bend when liquid is set in
                                                      motion by head or body
                                                      movements
                                                  Sent to Cerebellum
                                                    – Maintains balance/equilibrium
                                                    – Nothing to do with hearing
Pathway of Hearing

    Sound Waves ⇒          Cochlear Nerve
     pinna,or outer          (part of
     ear ⇒ Auditory          vestibulocochlear
     canal ⇒ tympanic        nerve)⇒ temporal
     membrane ⇒ ear          lobe of brain for
     ossicles (hammer,       interpretation
     anvil, stirrup)
     ⇒ stimulate the
     receptors in the
     cochlea ⇒
Did you know?

  Whales    can talk to each other even
   when 2 miles apart!!!!
  Why?

  Sound is transmitted through molecular
   collision
   – Transmission is better when molecules
     closer together as in liquid
Pathway of Equilibrium

    Movement of Head      Vestibular Nerve
     ⇒ Stimulates           (part of the
     equilibrium            vestibulocochlea
     receptors in           nerve) ⇒
     the                    Cerebellum of
     semicircular           the Brain for
     and vestibule          Interpretation
     areas of the
     inner ear ⇒
Loud Noise & Hearing Loss

    Hearing is:                            Repeated Exposure to
      – Sensitive                            loud noise
      – Fragile                              – Causes permanent
    Loud Noise                                damage as more cells
                                               are destroyed
      – Heard for too long
             Will damage Hearing
                                            Hearing Loss
             Delicate hair-like cells       – On increase in young
              of organ of Corti                people
              become over                           Due to loud music
              stimulated they                       Headphones
              become damaged
                                                    Sx of hearing loss
                                                       – Tinnitus – ringing
                                                         in the ears
How is sound measured?

    Decibels:
      – Faintest Sound Human can Hear
              Labeled dB to
      – Scream of a Jet Engine or shotgun blast
              165 dB
    Exposure to more than 90 dB (busy city traffic) for 8 hours may
     damage hearing
    At 100 dB (chain saw) for 2 hours would do the same damage
    Noise heard long enough and loud enough over time will cause
     damage
      – Protect your hearing
              Turn down the volume
              Wear earplugs
Ear Disorders

    Otitis Media
     – Infection Middle Ear
     – Sx – earache, hx of cold
     – Tx – antibiotics, prolonged, serious or chronic
       cases tx with
            Myringotomy
               – Opening in Tympanic Membrane
               – Tubes in ears

    Images of Tympanic Membrane
Otosclerosis

  Inherited   Disorder
    – Bone stapes of middle ear become
        Sponge and then harden
        Stapes become fixed and immovable
           – Common Cause of Deafness in Young Adults
           – Tx – Stapedectomy
               • Total replacement of the stapes
Tinnitus

  40-50 million Americans Affected
  Ringing in the Ears

  Caused by Damage to cells from loud
   noise
  Tx – underlying cause
Presbycusis

  Condition   of deafness
   – Due to aging process
   – Tx – hearing aids
Meniere’s Disease

  Affectsthe Semicircular Canals
  Causing Marked Vertigo (Dizziness)

  Sx appear at anytime and without
   warning
    – Can cause with it N/V
    – Tinnitus
  Tx   – bed rest, Meds, healthy diet
Types of Hearing Loss

    Conductive Hearing Loss
     – Sounds to inner ear blocked
            Ear wax
            Fluid
            Bug
            Abnormal bone growth
    Sensorineural Damage
     – To parts of inner ear or auditory nerve
            Deafness either complete or partial
            Profound Deafness
            Tx – Cochlear Implant – Children over 2 and adults
Sense of Smell/ Nose

  Human   Nose can detect
   – 10,000 different Smells
   – Smell counts for 90% of what we think of
     as taste
   – If you hold your nose may not be able to
     distinguish a difference between tastes
Nasal Cavity

    Patch of Tissue
      – Size of postage stamp
      – Called
    Olfactory Epithelium
      – Contains many nerve cells with
      – Specialized Receptors
    Receptors
      – Send Signals to
      – Olfactory Bulbs
    Extension of the Brain
Smell – Nasal Cavity

    Stimulus                    Explains why Odors
     – Transmitted by             are Tied to
     – Olfactory Nerve to          – Feelings
            Limbic System         – Ex. Associate smell of
            Thalamus                cooking with a good
            Frontal Cortex          experience
    Limbic System               Scientific Research
     – Basic Emotions              – Connecting Smells with
            Affection                    Learning
            Aggression                   Weight Loss
            Fear                         Aggression Levels
                                          Behavior
Disorders of the Nose

    Rhinitis                              –    Fumes
      – Inflammation of the                –    Odors
        lining of the Nose                 –    Emotional Changes
             Symptoms                     –    Drugs
                –   Nasal Congestion
                –   Nasal Drainage
                                          Tx
                –   Sneezing               – Eliminate Allergens
                –   Itching                – Antihistamines
    Caused By                             – Antibiotics
      – Allergies
      – Infection
Nasal Polyps

    Growths in             Sx
     – Nasal Cavity          – Same as Rhinitis
     – Caused by Sx of      Tx
             Rhinitis
         
                             – Severe Cases
                                     Surgical Removal
Deviated Nasal Septum

    Condition                                 Loud
                                                Breathing/Snoring
     – Bend in Cartilage                       Dry Nose/Nose
       Structure of the                         Bleeds
             Septum
         
                                      Tx
     – Sx
                                       – Surgical Correction
            Blockage of Air
             Flow                      – External Adhesive
            Difficulty Sleeping         Strip
            HA                                Temporary Relief
Sense of Taste/The Tongue

    Tongue                         Stimulate by
     – Mass of Muscle Tissue
       with                          Flavors of food
     – Papillae                     Receptors in Taste
              Taste buds located
                                     Buds
          
              on the papilla
    Taste Buds                        – Send stimuli
     –   Sweet                           through 3 Cranial
     –   Sour                            nerves to the
     –   Salty                               Cerebral Cortex
     –   Bitter
                                             Where interpreted
Taste/Tongue

    Before Tasted             Back of Tongue
     – Must be dissolved        – Bitter
     – By Saliva                       Stronger reaction
     – Produced by             Tip of Tongue
       Salivary Gland           – Sweet & Salty
    All Taste Buds can                Stronger Reaction
     detect all 4 Tastes;      Sides of Tongue
     however                    – Sour
                                       Stronger Reaction
Tongue Disorders

    Injury                      Causes
     – Bitten Accidently          – Fever
             Heals Quickly       – Antibiotic Tx
    Hairiness                    – Frequent Use of
     – Overgrowth of                Peroxide
       Normal Projections           Mouthwash
       on top of tongue
             Gives a hairy
              appearance
Discoloration

    Black
     – Taking Bismuth Prep for Upset stomach
    Pale
     – Iron deficiency (Anemia)
    White Patches
     –   Fever
     –   Dehydration
     –   Mouth Breathing
     –   Yeast infection
Tongue Infection

  Tongue   Piercing
Cancer of Tongue (CA)

    Sx
     – Unexplained Red/White
             Areas, Sores, or Lumps (hard)
             Painless
    Oral CA
     – Grows on sides of tongue or
     – Floor of Mouth
    Seek immediate Medical Attentin by
     – Dr or Dentist
Burning Mouth Syndrome

    Feels Like
      – Burned mouth with hot                – Mediation
        drink                                – Oral irritants
              But you didn’t                – Psychological factors
      – Syndrome Lasts for
                                            Tx
              A few weeks
                                             – Brushing/Flossing Daily
              Occurs most often after
               age 60                        – Avoiding Spicy/Acidic
    Causes                                    foods
                                                     Cinnamon
      – Medical Condition
                                                     Mint
      – Allergies                                    Hard Candies
      – Types of food                        – Chewing gum may help
                                               with pain
Effects of Aging on Smell

    Smell                           Senile Rhinitis
                                       – Clear, continuous, watery
     – Decrease in Olfactory             discharge
       Neurons                         – Without underlying disease
            Decreases
             awareness of odors
    Decrease in Sense of
     Smell affects
     – Appetite
     – Social Relationships
     – Detection of warning
       smells such as gas
Effects of Aging on Taste

    Taste                    Wearing Dentures
      – Diminished # of        – Diminishes Taste
        Taste Buds               sensation
      – Need increased              Cover taste
        amounts of                   Buds in
           Salt                       – Upper
           Sweet                        Palate
           Sour
           Bitter
      – To Identify Food
Career Profile

  Audiologists – Assess and treat pts with
   hearing and hearing related disorders
  Master’s Degree Needed

  Career Outlook Higher than average
   due to hearing loss due to aging
Career Profile – Optometrist

  Optometrists (Doctors of Optometry) –
   Provide primary vision care
   – Over half of Americans wear glasses
  Examine  Eyes
  Prescribe Eye Glasses/contacts
  Must be licensed
  Dr. Degree
  Career Profile: Dispensing
          Opticians

 FitEye Glasses/Contact Lenses
 Select Frames

 On-the-job training

 Job outlook also higher than average

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:15
posted:9/29/2012
language:English
pages:77