THE SPECIAL SENSES

Lab Objectives

Students should be able to:

1. identify the anatomical structures of the eye, ear and tongue.

2. discuss basic physiological function of each sense.

3. identify the microscopic anatomy of the tongue.

 

I.  ANATOMY:  BLANK DIAGRAMS
 
   A. Eye Model:

      1. fibrous tunic:  Picture 1, Picture 2
            a. sclera
            b. cornea
           
      2. vascular tunic (also called uvea): Picture 1
, Picture 2
            a. choroid layer
            b. ciliary body

            c. ora serrata retinae
            d. lens
            e. suspensory ligaments
            f. iris

            g. pupil

      3. Sensory tunic (retina):  Picture 1
            a. macula lutea
            b. fovea centralis
            c. optic disc
            d. optic nerve

       4. anterior segment or cavity (with aqueous humor):  Picture 1

       5. posterior segment or cavity (with vitreous body)
 
       6. extrinsic muscles:  Picture 1
             a. rectus group (superior, inferior, medial, lateral)
             b. obliques (superior, inferior)
 
       7.  conjuctiva
(not visible on models)

        8.  lacrimal gland  Picture 1

   B. Sheep Eye Dissection: Pic 1, Pic 2, Pic 3, Pic 4, Pic 5, and Pic 6. See the tutorial link at the bottom of the page as well!

        1.  Sclera

        2.  Cornea

        3.  Iris

        4.  Pupil

        5.  Ciliary body

        6.  Lens

        7.  Vitreous body

        8.  Retina with blind spot

        9.  Choroid layer with reflective portion

        10.  Optic nerve

 

  C. Ear Model: Except for pinna, all parts are housed within petrous portion of temporal bone.

       1. Outer ear:  Picture 1
             a. pinna
             b. external auditory (acoustic) meatus
             c. tympanic membrane

        2. Middle ear:  Picture 1
             a. ossicles
                 (1) malleus
                 (2) incus
                 (3) stapes
              b. auditory (pharyngotympanic) tube (formerly called the eustachian tube)

         3. Inner ear:  Picture 1
              a. bony labyrinth
                 (1) vestibule
                 (2) semicircular canals
                 (3) cochlea
              b. membranous labyrinth
                 (1) saccule
                 (2) utricle
                 (3) ampulla
                 (4) cochlear duct

 

         4. Nerves

               a. cochlear nerve

               b. vestibular nerve

               c. vestibulocochlear nerve (VIII)

 

    D.     Tongue:  Identify the following structures of the tongue.

          1.      Tongue model Picture 1, Picture 2

                a.   fungiform papillae

                b.      filiform papillae

                c.      circumvallate papillae

 

          2.      Tongue slide Picture 1
                a.   papillae
                b.   gustatory receptor (taste buds)
                c.   skeletal muscle
                d.   stratified squamous

 

      II. Useful Websites