Lab Activity: Special Senses
Part A: The Eye and Vision: Anatomy
1. Several accessory eye structures contribute to the formation of tears and/or aid in lubrication of the
eyeball. Match the described accessory structures with their secretion by choosing from the choices.
Conjunctiva
Lacrimal Glands
Tarsal Gland
a. Mucus
b. Oil
c. Salt Solution
2.
3.
4.
5.
The eyeball is wrapped in adipose tissue within the orbit. What is the function of the adipose tissue?
Why may it be necessary to blow one’s nose after having a good cry?
What is a sty? Conjunctivitis?
What seven bones form the bony orbit? (Think-if you can’t remember, check back to the skeletal system
chapter.)
6. Match the key responses with the descriptive statements that follow:
Aqueous humor
Cornea
Lens Sclera
Canal of Schlemm
Fovea Centralis
Optic Disc
Suspensory Ligament
Choroid
Iris
Retina
Vitreous Humor
Ciliary Body
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
Attaches the lens to the ciliary body
Fluid filling the anterior segment of the eye
The blind spot
Contains muscle that controls the size of the pupil
Drains the aqueous humor from the eye
“sensory” tunic
Substance occupying the posterior segment of the eyeball
Forms most of the pigmented vascular tunic
Tiny pit in the macula lutea; contains only cones
Important light-bending structures of the eye; shape can be modified
Anterior transparent part of the fibrous tunic
Composed of tough, white, opaque, fibrous connective tissue
7. The intrinsic eye muscle are under the control of which of the following? Autonomic Nervous System or
Somatic Nervous System
Part B: Visual Tests and Experiments
1. Use terms from the key to complete the statements concerning near and distance vision
Contracted
Decreased
Increased
Relaxed
Taut Lax
During distance vision: The ciliary muscle is __ (a)___, the suspensory ligament is ___(b)___, the
convexity of the lens is __(c)___, and light refraction is ___(d)__. During close vision: The ciliary muscle is
___(e)__, the suspensory ligament is ___(f)___, lens convexity is ___(g)__, and light refraction is __(h)___.
2. Explain why the part of the image hitting the blind spot is not seen.
3. Match the terms in Column B with the description in Column A:
Column A
a. Light bending
b. Ability to focus for close (under 20 ft) vision
c. Normal vision
d. Inability to focus well on close objects (farsightedness)
e. Nearsightedness
f. Blurred vision due to unequal curvatures of the lens or cornea
g. Medial movement of the eyes during focusing on close objects
Column B
accommodation
astigmatism
convergence
emmetropia
hyperopia
myopia
refraction
4. Define astigmatism.
5. How can you explain the fact that we see a great range of colors even though only three cone types
exist?
6. Many college students struggling through mountainous reading assignments are told that they need
glasses for “eyestrain.” Why is it more of a strain on the extrinsic and intrinsic eye muscles to look at
close objects than at far objects?