Download The Eye and Ear extra questions Key - Science-with

Exercise # 2: The Eye
1. The human eye is a complicated and sensitive sensory organ. To familiarize yourself with the
major parts of the eye, label the diagram below.
1)
2)
3)
4)
5)
6)
7)
Sclera
Choroid layer
Retina
Optic nerve
Blind spot
Fovea centralis
Conjuctive layer
(we didn’t talk
about this!)
8) Ciliary muscle
9) Iris
10) Lens
11) Pupil
12) Aqueous humour
13) Suspensory
ligaments
14) Cornea
15) Vitreous humour
2. Match each of the following functions with a part of the eye by placing the correct eye part in the
blank space provided.
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
a.)
b.)
c.)
d.)
e.)
f.)
g.)
h.)
i.)
j.)
k.)
l.)
m.)
n.)
Carries nerve signals to the brain. 4
Outermost layer (coat) of the eyeball. 1
Middle layer (coat) of the eyeball. 2
Inner layer (coat) of the eyeball that contains sensory information. 3
Regulates the size of the pupil to let more or less light in. 9
Refracts the light entering the eye. 14
Supplies the nutrients and oxygen to the lens, iris, and cornea. 12
Photoreceptor cells here transmit nerve signals to the brain. 3
Bends light rays and focuses them on the retina. 10
Changes the shape of the lens. 8
Photoreceptors are highly concentrated at this center of focus. 6
The fluid that provides nutrients for the lens and cornea. 12
The fluid that fills most of the eyeball. 15
Thin layer of transparent, living cells that overlies and protects much of the
cornea. 7
3. Light stimulation is converted by specialized sensory neurons, rods and cones, into __chemical
signal or action potential __, which travel to the brain and are interpreted in the ____occipital__
lobe.
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4. Indicate below the statements that relate to rods and those that relate to cones by placing the
correct term in the blank space. Use the terms “rods”,
“cones”, or “both rods and cones”.
__cones___
__ cones _
__rods ___
__ cones__
__ both___
___ rods__
__ cones_
___ rods__
___ both__
___ rods__
___ rods__
___ both_
__ cones _
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
m.
Comes in three types.
Stimulated by bright light.
Function in night vision.
Most numerous in the fovea.
Located in the back layer of the retina.
Contains a visual pigment called rhodopsin.
Can see different colors.
Absent from fovea.
Contains pigments called photopsins.
Most numerous at the outer edges of the retina.
See only shades of gray.
Transmit signals to the visual cortex.
Defective in color blindness.
5. What is accommodation reflex? Adjustments to bring things into focus- either faraway or close up
6. There are a number of reasons for less – than – perfect vision. Some people are near – sighted,
others far – sighted. Some suffer from astigmatism, cataracts, or glaucoma. Match each of the
statements with the aforementioned conditions. Some answers may be used more than once.
farsighted
a.
Distant objects clear; nearby objects unclear.
nearsighted
b.
Eyeball is too long; image focuses in front of retina.
astigmatism
c.
Misshapen cornea.
Cateracts
d.
Lens or cornea becomes cloudy.
Nearsighted (myoia)
e.
Nearby objects clear; distant objects unclear.
glaucoma
f.
Build – up of fluid in the anterior chamber to the lens.
Farsighted (hyperopia)
g.
Eyeball is too short; image focuses behind the retina.
7. A close object is viewed. If the eye was at rest, how does the lens need to change shape so the
object is clearly seen? Ciliary muscles contract, lens gets thicker
8. A far object is viewed. If the eye was at rest, how does the lens need to change shape so that
object is clearly seen? Ciliary muscles relax, lens gets thinner
9. The image formed on the retina is upside down. Why do we not see it this way? Brain interprets it
properly
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Exercise # 2: Touch, Taste, Smell
1. You travel to Vancouver for a vacation. When you arrive, the smell of salt is prominent. After
being in Vancouver for a while, the smell of salt “disappears”. This is because when an
unchanging stimulus is received by some neurons, they cease to generate impulses. Name this
process. Sensory adaptation
2. You travel to Vancouver for a vacation. When you arrive, the smell of salt is prominent. Why does
the smell of salt “disappear”, after being in Vancouver for a while? Neurons cease to fire
3. Identify the location where touch, pressure, temperature, and pain receptors are located. Skin
4. Would pain or touch receptors be located closer to the surface? Explain. Yes, to prevent cell
damage
5. What area of the cerebral cortex interprets impulses generated by touch receptors? Sensory
6. Identify the lobe of the cerebral cortex that has the sensory area for taste.
7. Name the five types of taste. Sour, sweet, bitter, savory, salty
8. What two senses work together to let us experience food? Taste and smell
9. Compare the sensory perception of taste to that of smell using a chart similar to the one below.
Similarities
Differences
Signal transduction
Location where they are found
Work together
Exercise # 3: The Ear
1. For each function, name the part of the ear described.
Ear drum
Oval window
Eustachian
tube
Pinna
a.
b.
c.
Saccule&utricle
Semicircular
Cochlea
Organ of corti
d.
e.
f.
g.
h.
i.
Otoliths
j.
Semicircular
k.
Middle ear
Inner ear
(cochlea)
(semicircular)
Auditory nerve
l.
m.
Temporal lobe
p.
Round window
n.
o.
Transfers sound waves to the ossicles.
Receives sound waves from the ossicles.
Tube that equalizes air pressure between the external ear and the middle
ear / throat.
Collects sound.
Bends outward to accommodate for oval window bending inward.
Senses static equilibrium.
Senses dynamic equilibrium.
Senses sound.
Structure within the cochlea specifically responsible for converting
vibrations of fluid to nervous impulses.
Little ear stones that bend over hair cells and cause a nerve impulse to be
generated.
When a figure skater twirls on ice, these organs of the inner ear respond
to changes in body position.
Air – filled portion of the ear.
Fluid – filled portion of the ear.
Fluid – filled portion of the ear.
Brain structures that receive impulses from the equilibrium organs of the
inner ear for interpretation.
Lobe of the brain that interprets sound.
2. On the diagram of the ear below, identify all of the numbered structures.
3
1)
2)
3)
4)
5)
6)
7)
Semicircular canal
Vestibule
Auditory nerve
Cochlea
Round window
Eustachian tube
Eardrum (tympanic
membrane)
8) Auditory canal
9) Pinna
10) Oval window
11) Stapes (stirrup)
12) Incus (anvil)
13) Malleus (hammer)
3. Name the type of deafness caused by a mechanical problem within the ear.
Conductive hearing loss
4. Name the type of deafness caused by a neural problem with the ear or brain.
Sensorineural hearing loss
Exercise # 4: All of the Senses
Review all the senses by matching each of the phrases on the right with a sensory structure from the
list on the left. Some answers are used more than once.
A.
B.
C.
D.
E.
F.
G.
H.
Retina
Semicircular
canal
Utricle and
saccule
Hair cell
Odor
receptor
Taste bud
Organ of
Corti
Cone
__8_____
__6_____
1.
2.
Receptors here detect changes in movement.
Receptors here sense sour, salty, sweet, and bitter.
__1&9___
3.
Chemicals dissolve in mucus and bind to its cilia.
__3_____
__4_____
4.
5.
Chemoreceptor of the nasal cavity.
Light receptor of the retina.
__2_____
__7_____
6.
7.
Receptors here sense position of head relative to gravity.
Receptor of hearing.
__5_____
_______
8.
9.
Site of photoreceptors.
Balance receptor.
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