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Test Bank For Human Anatomy & Physiology 9th Edition

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Test Bank For Human Anatomy & Physiology 9th Edition – Elaine N. Marieb

Test Bank For Human Anatomy & Physiology 9th Edition – Elaine N. Marieb

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What student Can Expect From A Test Bank?

A test bank will include the following questions:

  1. True/False
  2. Multiple Choice Questions
  3. Matching Questions
  4. Fill In The Blanks
  5. Essay Questions
  6. Short  Questions

 

Description

Exam

Name___________________________________

SHORT ANSWER.  Write the word or phrase that best completes each statement or answers the question.

Figure 15.1

Using Figure 15.1, match the following:

1)
Ganglion cells.
1)  
_____________

2)
Bipolar cells.
2)  
_____________

3)
Horizontal cell.
3)  
_____________

4)
Amacrine cell.
4)  
_____________

5)
Rod.
5)  
_____________

Figure 15.2

Using Figure 15.2, match the following:

6)
Protects and shapes the eyeball; provides a sturdy anchoring site for extrinsic eye muscles.
6)  
_____________

7)
Blood vessels supply nutrition to all eye layers.
7)  
_____________

8)
Contains only cones; provides detailed color vision.
8)  
_____________

9)
Lacks photoreceptors; where optic nerve exits the eye.
9)  
_____________

10)
Consists of a pigmented layer and a neural layer.
10)  
_____________

Figure 15.3

Using Figure 15.3, match the following:

11)
Acts as a reflexively activated diaphragm to vary pupil size.
11)  
_____________

12)
The only tissue in the body that can be transplanted from one person to another with little or no rejection.
12)  
_____________

13)
Controls lens shape.
13)  
_____________

14)
Holds the retina firmly against the pigmented layer.
14)  
_____________

15)
Fluid blockages cause glaucoma.
15)  
_____________

Figure 15.4

Using Figure 15.4, match the following:

16)
Pinna.
16)  
_____________

17)
Tympanic membrane.
17)  
_____________

18)
Stapes.
18)  
_____________

19)
Semicircular canals.
19)  
_____________

20)
Cochlea.
20)  
_____________

21)
Balance organ.
21)  
_____________

22)
Houses organ of Corti.
22)  
_____________

MATCHING.  Choose the item in column 2 that best matches each item in column 1.

Match the following:

23)
The sensory layer of the eye.
A)
Retina
23)
______

24)
The structure most responsible for focusing light rays that enter the eye.
A)
Aqueous humor
24)
______

B)
Lens

25)
Helps maintain the intraocular pressure; located in the anterior part of the eye.

25)
______

C)
Fovea centralis

26)
Area of greatest visual acuity.
26)
______

Match the following:

27)
Ear stones.
A)
Pharyngotympanic tube
27)
______

28)
Connects the middle ear with the nasopharynx.
B)
Otoliths
28)
______

C)
Tympanic membrane

29)
Separates external acoustic meatus from the middle ear.

29)
______

D)
Vestibule

30)

Contains utricle and saccule.
30)
______

31)
Detects linear acceleration.
31)
______

Match the following:

32)
A condition that can result from a deficiency of vitamin A.
A)
Otitis media
32)
______

B)
Night blindness

33)
A condition of deafness that may result from otosclerosis.

33)
______

C)
Conduction deafness

34)

An inflammation of the lining of the middle ear.
D)
Glaucoma
34)
______

35)
A condition often leading to blindness due to increased intraocular pressure.
35)
______

Match the following:

36)
Hair cells receptive to changes in dynamic equilibrium are found in this structure.
A)
Crista ampullaris  
36)
______

37)
Chemically sensitive microvilli found in this structure.
A)
Olfactory epithelium
37)
______

B)
Taste buds

38)
Hair cells receptive to changes in static equilibrium are found in this structure.

38)
______

C)
Macula

39)
Chemically sensitive cilia are found in this structure.
39)
______

Match the following:

40)
Houses the spiral organ (of Corti.)
A)
Cochlear duct
40)
______

41)
The receptor organ for hearing.
B)
Tympanic membrane
41)
______

42)
The central part of the bony labyrinth.
C)
Vestibule
42)
______

43)
A membrane that transmits sound vibrations to the auditory ossicles.
D)
Spiral organ (of Corti)
43)
______

Match the following:

44)
Loss of hearing resulting from prolonged exposure to high-intensity sounds.
A)
Sensorineural deafness
44)
______

B)

Tinnitus

45)

Can result from the fusion of the auditory ossicles.
C)
Conduction deafness
45)
______

46)
A possible side effect of medications such as aspirin.
46)
______

47)
One of the most common results of otitis media.
47)
______

48)
Can result from impacted cerumen.
48)
______

TRUE/FALSE.  Write ‘T’ if the statement is true and ‘F’ if the statement is false.

49)
The mucous membrane that lines the eyelids and is reflected over the anterior surface of the eyeball is the conjunctiva.
49)
______

50)
Vitamin D needed by the photoreceptor cells is stored by the cells of the retina pigmented layer.
50)
______

51)
The photoreceptor cells are sensitive to damage from light.
51)
______

52)
Static equilibrium involves linear acceleration as well as changes in head rotation.
52)
______

53)
The optic disc is the location where the optic nerve leaves the eyeball.
53)
______

54)
Sour taste receptors are stimulated by hydrogen ions of acidic food substances.
54)
______

55)
The fluid contained within the membranous labyrinth is called perilymph.
55)
______

56)
The extrinsic eye muscle motor units contain only 8 to 12 muscle cells and in some cases as few as 2 or 3 muscle cells.
56)
______

57)
Ciliary muscles are a type of skeletal muscle.
57)
______

58)
The structure that allows equalization of the pressure in the middle ear with that outside the body is the external auditory meatus.
58)
______

59)
The bending of light rays is called reflection.
59)
______

60)
The anterior chamber of the eye is filled with vitreous humor.
60)
______

61)
The neural layer of the retina prevents excessive scattering of light within the eye.
61)
______

62)
In order for sound to reach the spiral organ (of Corti), the auditory ossicles must vibrate the oval window and set the endolymph in motion.
62)
______

63)
Sound is generally perceived in the occipital lobe of the cerebral cortex.
63)
______

64)
Light passes through the entire thickness of the neural layer of the retina to excite the photoreceptors.
64)
______

65)
Without a functioning crista ampullaris, the semicircular canals would not function.
65)
______

66)
Contraction of the ciliary muscle causes the lens to bend the light less.
66)
______

67)
Theoretically, an individual born without a middle ear would be able to hear by bone conduction with a hearing aid.
67)
______

68)
When we move from darkness to bright light, retinal sensitivity is lost, but visual acuity is gained.
68)
______

69)
The function of the lens of the eye is to allow precise focusing of light on the retina.
69)
______

70)
Odorants must be volatile to be smelled.
70)
______

71)
Hair cells in the spiral organ of the ear are never replaced.
71)
______

72)
The quality of a sound is based on the atmospheric pressure at the time the sound is generated.
72)
______

MULTIPLE CHOICE.  Choose the one alternative that best completes the statement or answers the question.

73)
What is the main function of the rods in the eye?
73)
______

A)
color vision
B)
accommodation for near vision

C)
vision in dim light
D)
depth perception

74)
What structure regulates the amount of light passing to the visual receptors of the eye?
74)
______

A)
lens
B)
aqueous humor
C)
iris
D)
cornea

75)
Receptors for hearing are located in the ________.
75)
______

A)
cochlea
B)
tympanic membrane

C)
semicircular canals
D)
vestibule

76)
Which of the follow types of neurons are replaced throughout adult life?
76)
______

A)
retinal bipolar cells
B)
auditory outer and inner hair cells

C)
retinal ganglion cells
D)
olfactory receptor cells

77)
Bitter taste is elicited by ________.
77)
______

A)
metal ions
B)
hydrogen ions
C)
alkaloids
D)
acids

78)
The receptor for static equilibrium is the ________.
78)
______

A)
semicircular canals
B)
cochlear duct

C)
macula
D)
utricle

79)
Farsightedness is more properly called ________.
79)
______

A)
hyperopia
B)
hypopia
C)
presbyopia
D)
myopia

80)
Seventy percent of all sensory receptors are located in the ________.
80)
______

A)
skin
B)
ears
C)
nose
D)
eye

81)
Which of the following structures is not part of the external ear?
81)
______

A)
pharyngotympanic tube
B)
pinna

C)
external acoustic meatus
D)
tympanic membrane

82)
Nerve fibers from the medial aspect of each eye ________.
82)
______

A)
divide at the chiasma, with some crossing and some not crossing

B)
go to the superior colliculus only

C)
pass posteriorly without crossing over at the chiasma

D)
cross over to the opposite side at the chiasma

83)
Ordinarily, it is not possible to transplant tissues from one person to another, yet corneas can be transplanted without tissue rejection. This is because the cornea ________.
83)
______

A)
has no blood supply
B)
has no nerve supply

C)
does not contain connective tissue
D)
is not a living tissue

84)
The oval window is connected directly to which passageway?
84)
______

A)
scala vestibuli
B)
scala tympani

C)
pharyngotympanic tube
D)
external acoustic meatus

85)
There are three layers of neurons in the retina. The axons of which of these neuron layers form the optic nerves?
85)
______

A)
ganglion cells
B)
rod cells
C)
bipolar cells
D)
cone cells

86)
The first “way station” in the visual pathway from the eye, after there has been partial crossover of the fibers in the optic chiasma, is the ________.
86)
______

A)
lateral geniculate body of the thalamus
B)
visual cortex

C)
superior colliculi
D)
temporal lobe

87)
As sound levels increase in the spiral organ (of Corti), ________.
87)
______

A)
outer hair cells stiffen the basilar membrane

B)
outer hair cells bend the cilia away from the kinocilium

C)
inner hair cells bend the cilia away from the kinocilium

D)
inner hair cells stiffen the basilar membrane

88)
Which of the following is true about gustatory receptors?
88)
______

A)
All gustatory receptors have the same threshold for activation.

B)
In order for a chemical to be sensed, it must be hydrophobic.

C)
Complete adaptation occurs in about one to five minutes.

D)
The receptors generate an action potential in response to chemical stimuli.

89)
Taste buds are not found ________.
89)
______

A)
in circumvallate papillae
B)
in fungiform papillae

C)
lining the buccal cavity
D)
in filiform papillae

90)
Select the correct statement about olfaction.
90)
______

A)
Substances must be volatile and hydrophobic in order to activate olfactory receptors.

B)
Olfactory adaptation is only due to fading of receptor cell response.

C)
Olfactory receptors have a high degree of specificity toward a single type of chemical.

D)
Some of the sensation of olfaction is actually one of pain.

91)
What prevents the eyelids from sticking together when the eyes close?
91)
______

A)
tarsal gland secretions
B)
lacrimal fluid

C)
conjunctival fluid
D)
ciliary gland secretions

92)
Which of the following taste sensations is incorrectly matched to the chemicals that produce it?
92)
______

A)
salty—metal ions

B)
bitter—alkaloids

C)
sweet—organic substances such as sugar and some lead salts

D)
sour—acids

E)
umami—triglycerides and fatty acids

93)
Another name for the primary visual cortex is ________.
93)
______

A)
prefrontal cortex
B)
prestriate cortex

C)
collicular cortex
D)
striate cortex

94)
What is a modiolus?
94)
______

A)
a bone pillar in the center of the cochlea

B)
bone in the center of a semicircular canal

C)
a bony area around the junction of the facial, vestibular, and cochlear nerves

D)
bone around the cochlea

95)
Which statement about malnutrition-induced night blindness is most accurate?
95)
______

A)
Vitamin supplements can reverse degenerative changes.

B)
The impaired vision is caused by reduced cone function.

C)
Visual pigment content is reduced in cones more than rods.

D)
The most common cause is vitamin D deficiency.

96)
Dark adaptation ________.
96)
______

A)
results in inhibition of rod function

B)
is much faster than light adaptation

C)
involves accumulation of rhodopsin

D)
primarily involves improvement of acuity and color vision

97)
Conscious perception of vision probably reflects activity in the ________.
97)
______

A)
chiasma
B)
superior colliculus

C)
thalamus
D)
occipital lobe of the cortex

98)
In the visual pathways to the brain, the optic radiations project to the ________.
98)
______

A)
lateral geniculate body
B)
optic chiasma

C)
medial retina
D)
primary visual cortex

99)
Visual inputs to the ________ serve to synchronize biorhythms with natural light and dark.
99)
______

A)
superior colliculi
B)
pretectal nuclei

C)
lateral geniculate body
D)
suprachiasmatic nucleus

100)
Information from balance receptors goes directly to the ________.
100)
_____

A)
back muscles
B)
visual cortex

C)
motor cortex
D)
brain stem reflex centers

101)
Motion sickness seems to ________.
101)
_____

A)
result from activation of nausea centers in the brain stem

B)
respond best to medication that “boosts” vestibular inputs

C)
respond best to medication taken after salivation and pallor begins

D)
result from mismatch between visual and vestibular inputs

102)
The only special sense not fully functional at birth is the sense of ________.
102)
_____

A)
hearing

B)
taste

C)
smell

D)
vision

E)
equilibrium

103)
Most newborns ________.
103)
_____

A)
see in tones of red and green only
B)
are myopic

C)
often use only one eye at a time
D)
cry with copious tears

104)
The blind spot of the eye is where ________.
104)
_____

A)
more rods than cones are found
B)
the macula lutea is located

C)
the optic nerve leaves the eye
D)
only cones occur

105)
The first vestiges of eyes in the embryo are called ________.
105)
_____

A)
optic discs
B)
optic vesicles
C)
optic cups
D)
mesenchyme

106)
Which pairing of terms is incorrectly related?
106)
_____

A)
frequency of sound waves: number of wavelengths

B)
frequency of sound waves: loudness of the sound

C)
quality of a sound : frequency of the sound

D)
amplitude of a sound: intensity of the sound

107)
Olfactory cells and taste buds are normally stimulated by ________.
107)
_____

A)
substances in solution
B)
stretching of the receptor cells

C)
movement of a cupula
D)
the movement of otoliths

108)
Which of the following could not be seen as one looks into the eye with an ophthalmoscope?
108)
_____

A)
optic disc
B)
fovea centralis
C)
macula lutea
D)
optic chiasma

109)
The cells of the retina in which action potentials are generated are the ________.
109)
_____

A)
ganglion cells
B)
amacrine cells
C)
bipolar cells
D)
rods and cones

110)
8) During dark adaptation ________.
110)
_____

A)
the sensitivity of the retina decreases

B)
the rate of rhodopsin breakdown is accelerated

C)
the cones are activated

D)
rhodopsin accumulates in the rods

111)
Tinnitus, vertigo, and gradual hearing loss typify the disorder called ________.
111)
_____

A)
conjunctivitis
B)
motion sickness

C)
Ménière’s syndrome
D)
strabismus

112)
Which of the following is not a characteristic of olfactory receptor cells?
112)
_____

A)
They are chemoreceptors.

B)
They are unipolar neurons.

C)
They have a short life span of about 60 days.

D)
They are ciliated.

113)
An essential part of the maculae involved in static equilibrium is (are) the ________.
113)
_____

A)
scala media
B)
cupula

C)
otoliths
D)
spiral organ (of Corti)

114)
Which of the following is true about light and vision?
114)
_____

A)
Light is a form of electromagnetic radiation that slows down as it enters a medium of relatively less density.

B)
The greater the incident angle of light striking a refractive surface, the less the amount of light bending.

C)
Human photoreceptors respond to light in the 100-300 nm range.

D)
When we see the color of an object, all light is being absorbed by that object except for the color being experienced.

115)
The tarsal plate of the eyelid ________.
115)
_____

A)
is connected to the superior rectus muscle

B)
assists in the act of winking

C)
is connected to the levator palpebrae

D)
is composed of connective tissue surrounding a thin cartilage plate

116)
Which of the following is true about photoreceptors?
116)
_____

A)
Rods absorb light throughout the visual spectrum but confer only gray tone vision.

B)
If all cones are stimulated equally, all colors are absorbed by the cones and the color perceived is black.

C)
In dim light, images are focused directly on the rods in the fovea centralis.

D)
Three types of color-sensitive photoreceptors exist: red, green, and yellow.

117)
Select the correct statement about equilibrium.
117)
_____

A)
Due to dynamic equilibrium, movement can be perceived if rotation of the body continues at a constant rate.

B)
Hair cells of both types of equilibrium hyperpolarize only, resulting in an increased rate of impulse transmission.

C)
Cristae respond to angular acceleration and deceleration.

D)
The weight of the endolymph contained within the semicircular canals against the maculae is responsible for static equilibrium.

118)
The eye muscle that elevates and turns the eye laterally is the ________.
118)
_____

A)
lateral rectus
B)
superior oblique

C)
medial rectus
D)
inferior oblique

119)
The receptor membranes of gustatory cells are ________.
119)
_____

A)
basal cells
B)
fungiform papillae

C)
gustatory hairs
D)
taste buds

120)
Light passes through the following structures in which order?
120)
_____

A)
cornea, vitreous humor, lens, aqueous humor

B)
cornea, aqueous humor, lens, vitreous humor

C)
aqueous humor, cornea, lens, vitreous humor

D)
vitreous humor, lens, aqueous humor, cornea

121)
Damage to the medial rectus muscles would probably affect ________.
121)
_____

A)
pupil constriction
B)
refraction

C)
convergence
D)
accommodation

122)
Which statement about sound localization is not true?
122)
_____

A)
It requires processing at the cortical level.

B)
It uses time differences between sound reaching the two ears.

C)
It is difficult to discriminate sound sources in the midline.

D)
It requires input from both ears.

123)
Which of the following is not a possible cause of conduction deafness?
123)
_____

A)
otosclerosis
B)
middle ear infection

C)
cochlear nerve degeneration
D)
impacted cerumen

124)
Visual processing in the thalamus does not contribute significantly to ________.
124)
_____

A)
night vision
B)
high-acuity vision

C)
depth perception
D)
movement perception

125)
Visible light fits between ________.
125)
_____

A)
microwaves and radio waves
B)
UV and infrared

C)
infrared and microwaves
D)
X rays and UV

126)
Ceruminous glands are ________.
126)
_____

A)
glands found in the lateral corners of your eye

B)
modified taste buds

C)
saliva glands found at the base of the tongue

D)
modified apocrine sweat glands

SHORT ANSWER.  Write the word or phrase that best completes each statement or answers the question.

127)
High frequency sounds are detected when the basilar membrane is displaced near the____.
127)  
____________

128)
The synapse of the olfactory nerves with the mitral cells is called a ________.
128)  
____________

129)
The rocks found in one’s head (calcium carbonate crystals) are called ________.
129)  
____________

130)
The middle ossicle in the ear is the ________.
130)  
____________

131)
The ________ nuclei are in the visual pathway and mediate the pupillary light reflexes.
131)  
____________

132)
Taste is solely a response to chemicals dissolved in ________.
132)  
____________

133)
Taste sensation also involves chemoreceptors, thermoreceptors, mechanoreceptors, and ________.
133)  
____________

134)
The apex of the cochlea hears sounds in the range of ________ Hz.
134)  
____________

135)
In the optic ________ the visual fields of the axons are all ipsilateral.
135)  
____________

136)
Contrast light and dark adaptation and include the role of the rods and cones.
136)  
____________

137)
What is the chemical composition of the rod pigment, rhodopsin, and how does it appear to act in the reception of light?
137)  
____________

138)
After head trauma from an automobile accident, a man has anosmia. Define anosmia. Why is this condition fairly common after such injuries and in cases of severe nasal cavity inflammation?
138)  
____________

139)
Explain why your nose runs during and immediately after a good cry.
139)  
____________

140)
Trace the pathway of sound as it enters the external ear until it is perceived in the brain.
140)  
____________

141)
Explain the role of the endolymph of the semicircular canals in activating the receptors during angular motion.
141)  
____________

142)
What two things does the ciliary body do?
142)  
____________

143)
When you go to the fair and ride the roller coaster, where do those wild sensations come from?
143)  
____________

144)
What is the pharyngotympanic tube and what is its purpose?
144)  
____________

145)
Explain why prolonged periods of reading tire the eye muscles and result in eye strain.
145)  
____________

146)
Where in the body is the only place where small blood vessels can be observed directly in a living person?
146)  
____________

147)
Distinguish between the maculae and cristae ampullaris in terms of their sensory reception.
147)  
____________

148)
Explain why a bad cold can result in food not tasting the same as it normally does.
148)  
____________

ESSAY.  Write your answer in the space provided or on a separate sheet of paper.

149)
Roger went for his yearly eye examination and was informed that his intraocular pressure was slightly elevated (at 22 mm Hg). The physician expressed concern over this condition and noted that if the condition got worse, eye drops would be merited. What is wrong with Roger’s eyes, and what are the possible consequences of this condition? Explain the function of eye drops used for therapy.

150)
Baby Susie’s pediatrician notices that one of her eyes rotates outward and that she does not appear to be using it for vision. What is her condition and what does the pediatrician recommend?

151)
A 60-year-old woman is experiencing vertigo. She ignores the symptoms initially, but now her attacks are accompanied by severe nausea and vomiting. Following an attack, she hears a roaring in her ears that causes temporary deafness for some time after. What do you think her problem is, and what is its suspected cause?

152)
Ling, a 75-year-old grandmother, complained that her vision was becoming obscured. Upon examination by an ophthalmologist she was told she had cataracts. What are they, how do they occur, and how are they treated?

153)
A nurse is administering Pilocarpine eye drops. The nurse instructs the patient to press on the nasolacrimal duct for 30 seconds because the medication can have some systemic side effects, such as affecting the heart rate. Explain the rationale for pressing on the nasolacrimal duct.

1)
E

2)
C

3)
A

4)
D

5)
B

6)
A

7)
B

8)
D

9)
E

10)
C

11)
C

12)
B

13)
A

14)
E

15)
D

16)
A

17)
E

18)
C

19)
B

20)
D

21)
B

22)
D

23)
D

24)
B

25)
A

26)
C

27)
B

28)
A

29)
C

30)
D

31)
D

32)
B

33)
C

34)
A

35)
D

36)
D

37)
B

38)
C

39)
A

40)
A

41)
D

42)
C

43)
B

44)
A

45)
C

46)
B

47)
C

48)
C

49)
TRUE

50)
FALSE

51)
TRUE

52)
FALSE

53)
TRUE

54)
TRUE

55)
FALSE

56)
TRUE

57)
FALSE

58)
FALSE

59)
FALSE

60)
FALSE

61)
FALSE

62)
TRUE

63)
FALSE

64)
TRUE

65)
TRUE

66)
FALSE

67)
TRUE

68)
TRUE

69)
TRUE

70)
TRUE

71)
FALSE

72)
FALSE

73)
C

74)
C

75)
A

76)
D

77)
C

78)
C

79)
A

80)
D

81)
A

82)
D

83)
A

84)
A

85)
A

86)
A

87)
A

88)
C

89)
D

90)
D

91)
A

92)
E

93)
D

94)
A

95)
A

96)
C

97)
D

98)
D

99)
D

100)
D

101)
D

102)
D

103)
C

104)
C

105)
B

106)
B

107)
A

108)
D

109)
A

110)
D

111)
C

112)
B

113)
C

114)
D

115)
C

116)
A

117)
C

118)
D

119)
C

120)
B

121)
C

122)
A

123)
C

124)
A

125)
B

126)
D

127)
base

128)
glomerulus

129)
otoliths

130)
incus

131)
pretectal

132)
saliva

133)
nociceptors

134)
20

135)
tract

136)
Rods respond to low-intensity light that provides night and peripheral vision, while cones are bright-light, high-discrimination receptors that provide color vision. During light adaptation, rods are inactivated and as cones respond to the high-intensity light, high visual acuity results. In dark adaptation, cones do not function (visual acuity decreases) and rod function resumes when sufficient rhodopsin accumulates.

137)
Rhodopsin is a combination of retinal and opsin. Retinal is chemically related to vitamin A and is synthesized from it. Retinal can form a variety of three-dimensional forms called isomers. The opsin protein combines with the 11-cis retinal to form rhodopsin. The light-triggered changes in retinal cause hyperpolarization of the rods. This happens because the light turns off sodium entry, which then inhibits the release of neurotransmitter, thus turning off electrical signals.

138)
Anosmia means the loss of chemical sense of smell due to some olfactory disorder. Most anosmia results from head injuries or nasal cavity inflammations, allergies, smoking, and aging. The olfactory pathways are very sensitive to irritations or to damage, especially if the ethmoid bones have been damaged due to trauma.

139)
The tears flow into the lacrimal canaliculi and then into the nasolacrimal sac. As the sac fills, the tears begin to run down the nasolacrimal duct and out your nose.

140)
A sound wave passing through the external acoustic meatus causes the eardrum to vibrate at the same frequency as the wave. The auditory ossicles amplify and deliver vibrations to the oval window. Pressure waves in the cochlear fluids cause basilar membrane resonance that stimulates the hair cells of the spiral organ (of Corti). Impulses are then generated along the cochlear nerve that travel to the cochlear nuclei of the medulla and, from there, through several brain stem nuclei to the auditory cortex of the brain.

141)
The crista ampullaris responds to changes in the velocity of head movement (angular acceleration). The crista consists of a tuft of hair cells whose microvilli are embedded in the gelatinous cupula. Rotational movement causes the endolymph to flow in the opposite direction, thus bending the cupula and exciting the hair cells.

142)
1. Constriction of the ciliary muscle that is attached to the lens via the ciliary zonule causes the lens to change shape.

2. The epithelium of the ciliary body secretes aqueous humor.

143)
The wild sensations occur when the receptor for dynamic equilibrium, the crista ampularis, is excited by endolymph moving in the semicircular canals. This movement is the result of rotational acceleration or deceleration. Many times these wild rides spin us around enough that our eyes tell us we are going one way but the vestibule and semicircular canal tell us something different. Conflicts like that can often cause us to get quite dizzy or even sick.

144)
The pharyngotympanic tube links the middle ear cavity with the nasopharynx. Normally it is flattened and closed, but swallowing or yawning opens it briefly to equalize pressure in the middle ear cavity with external air pressure.

145)
Reading or other close work requires almost continuous accommodation, pupillary constriction, and convergence, which lead to tiredness of the eye muscles.

146)
fundus of the eye

147)
Maculae are sensory receptors for static equilibrium. They monitor the position of the head in space by responding to linear acceleration forces. Cristae ampullaris respond to rotary (angular) movements.

148)
Taste is 80% smell. When the ability to smell is blocked due to nasal congestion, taste is primarily via the taste receptors which account for only about 20% of the taste sensation. This results in a distinct difference in the “taste” of food,

149)
If the drainage of the aqueous humor is blocked, pressure within the eye can increase, causing compression of the retina and optic nerve, resulting in a condition called glaucoma. The resulting destruction of the neural structures causes blindness unless the condition is detected early. Early glaucoma can be treated with eye drops that increase the rate of aqueous humor drainage or decrease its production.

150)
Susie has strabismus, caused by congenital weakness of the external eye muscles in her affected eye. To prevent this eye from becoming functionally blind, the doctor will recommend either eye exercises or putting a patch on the unaffected eye to force her to use the affected eye. If her case is deemed severe, surgery on the eye muscles will be recommended.

151)
She most likely has a condition known as Ménière’s syndrome. It affects both the semicircular canals and the cochlea. The cause of the syndrome is uncertain, but it may result from distortion of the membranous labyrinth by excessive endolymph accumulation. Less severe cases can usually be managed by antimotion drugs. For more debilitating attacks, salt restriction and diuretics are used to decrease overall extracellular fluid volumes.

152)
A cataract is a clouding of the lens that causes the world to appear distorted, as if looking through frosted glass. Some cataracts are congenital, but most are due to age-related hardening and thickening of the lens, or are a possible consequence of diabetes mellitus. The direct cause is probably inadequate delivery of nutrients to the deeper lens fibers. The metabolic changes that result are thought to promote unfolding of the lens proteins. Unprotected exposure to the UV rays of sunlight over time is also associated with cataract formation. The lens can be removed and replaced with an artificial lens.

153)
Applying gentle pressure to the nasolacrimal duct prevents the delivery of the drug to the nasal mucosa and general circulation, where it may affect heart rate.