LABORATORY NINE

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LABORATORY NINE

• Special Senses

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Cow Eye Dissection(Google, Image, Cow Eye
Dissection)

• Identify the assigned superficial structures
• Make a coronal section
• With the scalpel make an incision 1cm (the width
  of the scalpel's blade) below the junction of
  cornea sclera
• With scissors cut around the cornea keeping the
  1cm distance from the junction all around
• To remove the jellylike transparent substance,
  hold down the lens by left thumb and scoop out
  the jellylike substance by right thumb
• Detach the lens from the iris
• Scoop out the jellylike substance from the
  posterior cavity very gently not to disturb the
  retina (immerse the posterior part of the cow eye
  in the water to reshape the retina)
• Identify the assigned structures
• Use the human eye model to study the muscles
  responsible for eye movement

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Sensory Nerve Endings in the Skin
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Cutaneous Sensation(Exercise 9A, P151)

• 2 3, p152 Two-point discrimination test
• 4, p152 Duration of sensation
• Subjects eyes should be closed
• Record your observations in the related section
  in your lab report

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Muscles of the Eye

• To identify the medial/lateral ends of the eye
• For superior/inferior oblique muscles, their
  attached part to the sclera is the more lateral
  side
• Optic nerve II is located more medially

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Sagittal Section of the Eye
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Vision(Exercise 9B, p153)

• 4, p153 Blind spot test
• 5, p154 Visual acuity
• 6, p154 Astigmatism
• 7, p155 Color blindness
• Record your results in the related section in
  your lab report

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External, Middle, and Inner Ear
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Organ of Corti(Observe the model demonstration
microscope)
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Hearing and Equilibrium(Exercise 9C, p155)

• 3, p156 Hearing acuity test
• 4, p157 Ability to locate the source of a sound
• 5, p157 The Rinne test
• 6, p157 Evaluation of balance
• Subjects eyes should be closed
• Record your observations in the related section
  in your lab report

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The Tongue

• (a) Dorsal Surface
• (b) Papilla (enlargements on the surface of the
  tongue)
• (c) Taste bud (view the microscopic slide)

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Taste and Olfaction(Exercise 9D, p158)

• Test your sense of taste using a taste paper
• Record your results in the related section in
  your lab report