Worksheet X: The Eye and Ear
1. Identify the accessory eye structures based on the
descriptions given below.
a. Anterior, fleshy cover of connective tissue
sheets
over eyes.
_____________________________
b. Richly innervated with nerve endings that
trigger
blinking when touched.
_____________________________
c. Short, coarse hairs superiorly located on
orbital ridge. ___________________________
d. Lines inner surface of eyelids and surface
of exposed
eye.
_____________________________
e. Shades eyes from sunlight and prevents
moisture
(perspiration) from entering eye.
_____________________________
f. Releases saline secretion called
tears.
_____________________________
g. Prevents the eye from drying by spreading
oils, mucus,
and saline solutions across eye's
surface.
_____________________________
h. Attached to sclera of the eye; causes eye
movements. ___________________________
i. Superiorly located gland that produces an
oily
lubricant that prevents the eyes from sticking
together._____________________________
j. Duct that drains tears into nasal
cavity.
_____________________________
k. Within orbit above lateral side of
eye.
_____________________________
2. Name 4 substances found in tears.
_____________________________
_____________________________
_____________________________
_____________________________
3. The eyeball is composed of three layers called:
_____________________________
4. Name the 3 layers indicated in question #3.
_____________________________
_____________________________
_____________________________
5. The fibrous tunic is divided in the anterior
_____________________________ and the posterior
__________________________.
6. Identify the parts of the eye based on the descriptions given
below.
a. Divides eye into anterior and posterior
cavities. _____________________________
b. Highly vascular, pigmented, posterior part
of eyeball.____________________________
c. White and opaque covers most of eye
posteriorly and
laterally.
_____________________________
d. Point for extrinsic eye muscle
attachment.
_____________________________
e. Thickened ring of tissue encircling
lens. _____________________________
f. Anteriormost and transparent.
_____________________________
g. Dense, avascular, and opaque
connective tissue. _____________________________
h. Pigmented and anterior; flattened doughnut
shape. _____________________________
i. Ligament attached to len's
surface.
_____________________________
j. Protects and anchors eyeball;
maintains shape. _____________________________
k. Becomes continuous with dura mater of
brain.
_____________________________
l. Smooth muscle that controls len's
shape.
_____________________________
m. Posterior region of middle tunic.
_____________________________
n. Innermost tunic.
_____________________________
o. Secretes aqueous humor of the eye.
_____________________________
p. The opening in the iris.
_____________________________
q. Single layer of simple cuboidal
cells.
_____________________________
r. Area inside eye where axons of ganglion
cells exit. _____________________________
s. Layer housing 3 layers of
neurons.
_____________________________
t. Axons of ganglion cells exit rear of
eye. _____________________________
u. Lateral to optic disc; yellowish area
containing mostly cones. _______________________
7. Give the correct tunic (fibrous, vascular, sensory) for the
structures listed below.
a.
iris................................................................................
_______________________
b. retina
...........................................................................
_______________________
c. cones
...........................................................................
_______________________
d. sclera
.............................................................................
_______________________
e. cornea
..........................................................................
_______________________
f. ciliary body
.....................................................................
_______________________
g. choroid
..........................................................................
_______________________
h. neural layer
....................................................................
_______________________
8. When the ciliary body contracts, the suspensory ligament __a__
(contracts/relaxes), and causes the lens to become __b__
convex.
a. ___________________________
b. ___________________________
9. The iris is composed of 2 layers of smooth muscle, the __a__
smooth muscle that dilates the pupil and the __b__ smooth muscle that
constricts the pupil. a.
___________________________
b. ___________________________
10. Give 2 functions for the pigmented layer of the
retina.
_____________________________
_____________________________
11. Name the 3 neurons of the neural layer in the sequence
light strikes them.
_____________________________
_____________________________
_____________________________
12. The small pit in the center of the macula lutea that contains
only cones is the:
____________________________.
13. __a__ are slender neurons with a long cylindrical __b__ segment
immersed in the __c__ layer of the retina. __a__ detect
black-white light and are __d__ (centrally/perpherally) located
on the retina. The heavier __e__ have a short conical __f__
segment and are concentrated in the __g__ of the retina. __e__
detect __h__ light. Discs of light-absorbing pigments are
concentrated in the __i__ segments of these photoreceptors.
a. ____________________________
f. __________________________
b. ____________________________
g. __________________________
c. ____________________________
h. __________________________
d. ____________________________
i. __________________________
e. ____________________________
14. The eyeball is divided into 2 cavities by the lens; a(n)
__a__ cavity that houses a plasma-like substance called the __b__ and
a(n) __c__ cavity that contains a gel-like substance of connective
tissue called the __d__. The __a__ cavity is divided into 2
chambers; a(n) __e__ chamber between the cornea and the iris and a(n)
__f__ chamber between the iris and the lens. The __g__ of the
ciliary body secrete the __b__ and this fluid is drained from this
chamber by the __h__ into the bloodstream.
a. ____________________________
f. __________________________
b. ____________________________
g. __________________________
c. ____________________________
h. __________________________
d. ____________________________
e. ____________________________
15. The lens is a _______________________ (shape), transparent
disc composed of the protein ___________________________.
16. The ______________________________ includes x-rays, gamma rays,
infrared radiation, UV radiation, and visible light.
17. Light travels in waves or in packages of light energy called:
__________________________.
18. The bending of light as it travels from one medium to another
is called:___________________.
19. Light bouncing off the surface of an object is termed:
____________________________.
20. Light rays passing through a convex lens __a__
(converge/diverge/remain parallel) and/but form a(n) __b__ that is
__c__ (right side up/upside down) and __d__ (reversed/oriented
correctly). The distance between the lens and the __b__ is called
the __e__. The __e__ becomes __f__ (longer/shorter) as the lens
becomes more convex.
a. ____________________________
d. __________________________
b. ____________________________
e. __________________________
c. ____________________________
f. __________________________
21. The following structures are parts or actions of a camera. How does
our eye simulate each?
a. Diaphragm
____________________________
b. Film
____________________________
c. Focus
____________________________
22. Light is bent 3 times as it enters the eye. List the most important
first and the least important last.
____________________________
____________________________
____________________________
23. For distances greater than 20 feet, light rays enter the eye
__a__ (diverging/converging/ parallel). The ciliary muscles
__b__ (relax/contract) and the suspensory ligament is __c__
(relax/contract) causing the lens to be __d__ (more/less) convex.
a. ____________________________
c. __________________________
b. ____________________________
d. __________________________
24. For distances less than 20 feet, light rays enter the eye __a__
(diverging/converging/ parallel). The ciliary muscles __b__
(relax/contract) and the suspensory ligament is __c__ (relax/contract)
causing the lens to be __d__ (more/less) convex.
a. ____________________________
c. __________________________
b. ____________________________
d. __________________________
25. To restore proper focus for close up vision 3 processes must
occur. They are:
___________________________
___________________________
___________________________
26. Identify which of the 3 processes from question 25 are being
described below.
a. Iris reduces the size of the pupil.
___________________________
b. Ciliary muscles contract.
___________________________
c. Circular smooth muscles contract.
___________________________
d. Medial rectus muscles (an extrinsic eye muscle)
contract.
___________________________
e. Most divergent light rays prevented from
entering
the eye.
___________________________
f. Increases depth of field for better
focus. ___________________________
27. Identify the eye problem based on the descriptions given below.
a. Proteins unfold and cloud lens.
___________________________
b. Non accommodating lens.
___________________________
c. Aqueous humor drainage is blocked
causing
increased pressure.
___________________________
d. Can see only close objects clearly.
___________________________
e. Vitamin A deficiency; cannot see well at
night. ___________________________
f. A sex-linked genetic defect for production of
some or
all cones.
___________________________
g. Eye is too long or lens too powerful.
___________________________
h. Distant objects in focus, close objects
not. ___________________________
i. Unequal curvatures of the cornea or
lens. ___________________________
j. Eye too short or lens weak.
___________________________
k. Corrected with concave lens that diverges
light before
enters eye.
___________________________
l. Occurs when focusing on close objects for
long
periods of time.
___________________________
m. Corrected with special cylindrically ground
lenses. ___________________________
28. __a__ is a light-absorbing molecule that combines with
proteins called __b__. __a__ combines as the __c__ isomer and
detaches from the __b__ when it changes to the __d__ isomer. In
rods, the __c__ isomer combines with __e__ to form the visual pigment
__f__. __f__ is stored in the __g__ of the rods. In the
dark, __h__ ions leak into the __g__ of the rods, depolarizing the
membrane and causing the release of a(n) __i__ neurotransmitter to the
bipolar cells. The signal travels no further. However, in
the light, __f__ is broken down into __e__ and the __j__ isomer .
A series of reactions results in blocking the entry of __h__ ions and
__k__ (depolarizes/repolarizes/hyperpolarizes) the rod cells. The
__i__ neurotransmitter is not released and the bipolar cells can now
__l__ (depolarize/repolarize/ hyperpolarize).
a. _____________________________
g. ___________________________
b. _____________________________
h. ___________________________
c. ____________________________
i.
__________________________
d. ____________________________
j.
__________________________
e. ____________________________
k.
__________________________
f. ____________________________
l.
___________________________
29. The 3 basic opsins of cones are generally called:
_____________________________
30. Name the 3 kinds of cones and the approximate wavelengths of light
they respond to>
_____________________________
_____________________________
_____________________________
31. Cones require ____________________ (bright/dim) light to be
activated and detect ____________________.
32. _______________________ occurs when one moves from bright light
into darkness.
33. _______________________ occurs when one moves from darkness into
bright light.
34. The axons of ganglion cells exit the eyeball forming the
__a__. The __a__ merge and criss-cross at the __b__. The medial
fibers __c__ (do/do not) cross over and/while the lateral fibers __d__
(do/do not) cross over. These fibers form the __e__ tracts which
synapse in the __f__ and continue on to the __g__
cortex in the __h__ lobes. Some fibers also synapse in the
__i__ and are responsible for visual reflexes.
a. _____________________________
f. ___________________________
b. _____________________________
g. ___________________________
c. ____________________________
h.
__________________________
d. ____________________________
i.
__________________________
e. ____________________________
35. The ear is divided into 3 main areas. Name them.
____________________________
____________________________
____________________________
36. Identify these structures in or associated with the first 2 areas
of the ear based on the descriptions given below.
a. Short, narrow canal from auricle to
tympanic membrane. _________________________
b. A yellow-brown wax that traps foreign
debri. ____________________________
c. Connects middle ear with
nasopharynx.
____________________________
d. Shell-shaped projection at lateral side of
head. ____________________________
e. Composed of elastic cartilage; directs sound
waves. ___________________________
f. Fibrous connective tissue and skin that
vibrates as air
hits it.
____________________________
g. Equalizes pressure on both sides of
eardrum.
____________________________
h. Middle ear ossicle.
____________________________
i. Ossicle anchored to eardrum.
____________________________
j. Muscle that inserts on malleus.
____________________________
k. Muscle that inserts on stapes.
____________________________
l. Ossicle that connects to oval
window.
____________________________
m. Glands that secrete cerumen.
____________________________
n. Dampens vibration created by loud
noises.
____________________________
37. The inner ear is composed of __a__ and __b__
labyrinths. The __a__ labyrinth is lined with the endosteum of
the __c__ bone and is filled with a CSF-like fluid called __d__.
The __b__ labyrinth is contained within the __a__ labyrinth and floats
in __d__. __e__ , a fluid similar to ICF, fills the __b__
labyrinth. The __a__ labyrinth is divided into 3 parts; the
__f__, __g__, and __h__. The __f__ is the central area that
receives both the oval and round windows. The __g__ are a series
of 3 canals oriented in different planes and the __h__ is a snail-shell
shaped structure that contains the receptors for hearing.
a. _____________________________
e. ___________________________
b. _____________________________
f. ___________________________
c. ____________________________
g.
__________________________
d. ____________________________
h.
__________________________
38. The membranous labyrinth of the vestibule is divided into the
__a__ and __b__. The __a__ contains receptors called __c__ that
are important in monitoring changes in head position. The __b__
also contain receptors called __c__ that are important in detecting
straight-line acceleration and deceleration. Movement of
specialized __d__ cells activate receptor cells whose axons form the
__e__ nerve.
a. _____________________________
d. ___________________________
b. _____________________________
e. ___________________________
c. ____________________________
39. The names of the 3 semicircular canals are:
____________________________
____________________________
____________________________
40. Each semicircular canal has an enlarged end at its base
called a(n) __a__. The __a__ houses receptors called __b__.
__c__ (Rotary angular/Linear/Acceleration) movements activate __d__
cells. Sensory fibers encircle the base of these cells. As
fluid moves through the semicircular canals, the receptors are
activated and send impulses to the brain by the __e__ nerve.
a. _____________________________
d. ___________________________
b. _____________________________
e. ___________________________
c. _____________________________
41. Identify the parts of the cochlea based on the descriptions given
below.
a. Middle canal of cochlea.
_____________________________
b. Canal that is continuous with oval
window.
_____________________________
c. Floor of the middle canal of the
cochlea.
_____________________________
d. Canal that terminates at round
window.
_____________________________
e. Fluid in middle canal of cochlea.
_____________________________
f. Fluid in superior and inferior
canals.
_____________________________
g. Thicker near oval window and wider and
thinner near
cochlea apex.
_____________________________
h. Hairs embedded in this membrane.
_____________________________
i. Membrane that receives stapes and is
beginning of
superior canal.
_____________________________
j. Terminal membrane of inferior
canal.
_____________________________
42. Put these structures in the sequence that sound travels into the
inner ear: Pinna, Organ of Corti, malleus, tympanic membrane,
round window, oval window, auditory canal, incus, stapes.
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
43. The number of crests that pass a given point in a given time is
termed: _______________________.
44. The distance between 2 adjacent crests is termed:
_____________________________.
45. What is range of human hearing in hertz?
_____________________________
46. The unit of frequency is the:
_____________________________.
47. The shorter the wavelength the ____________________
(higher/lower) frequency.
48. The amount of energy in a sound wave is shown graphically by the:
_______________________.
49. Different sound frequencies are termed:
____________________________.
50. The unit of amplitude is the:
____________________________.
51. A mixture of pitches is termed:
____________________________.
52. ______ decibels is the threshold for human hearing while _______
decibels is the level of excruciating pain.
53. The surface area of the tympanic membrane is approximately
______ times the surface area of the oval window. This
relationship is important because:___________________________________.
54. As the stapes vibrates against the __a__, it sets the__b__ in a
back and forth motion. The __c__ bulges in response to
these pressure changes. These pressure waves travel through the
__b__ from the basal end to the apex, or helicotrema. The __d__
membrane swings up and down causing the __e__ to ossillate, but only in
the area structurally receptive to a certain sound
__f__. The hairs of the __d__ membrane are __g__ (short and
rigid/long and floppy) near the __a__ and __h__ (short and rigid/long
and floppy) near the cochlear apex. There is a(n) __i__
(gradual/abrupt) change from one end to the other. The
__j__ rests on top of the __d__ membrane. Hairs from this __j__,
called __k__, are embedded in the overlying __l__ membrane. As
this membrane swings up and down, __m__ gated channels are opened that
lead to EPSPs called __n__. Neurotransmitters released from these
hair cells may give rise to action potentials carried by the __o__
nerve. The __o__ nerve joins with the __p__ nerve forming the
__q__ nerve. The __q__ nerve carries impulses to the
medulla and on to the __r__ cortex of the __s__ lobe with some fibers
synapsing in the __t__. The __t__ is responsible for auditory
reflexes.
a. _____________________________
k. ___________________________
b. _____________________________
l. ___________________________
c. ____________________________
m.
__________________________
d. ____________________________
n.
__________________________
e. _____________________________
o. ___________________________
f. _____________________________
p. ___________________________
g. ____________________________
q.
__________________________
h. ____________________________
r.
__________________________
i. _____________________________
s. ___________________________
j. _____________________________
t. ___________________________
55. Explain what happens during light adaptation.
_______________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
56. Your eyes house red-sensitive, green-sensitive, and blue-sensitive
cones. Explain why we can see hundreds of different color shades
with only 3 different color-sensitive cones. _____________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
57. What are and what causes cataracts?
_____________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
58. What is and what causes glaucoma?
_______________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
59. What is and what causes myopia? How is this condition
corrected? ______________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
60. Draw an eye (only including the lens and retina) demonstrating the
condition of hyperopia. _____
61. How is your inner ear protected from loud noises?
__________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________