CSD 210 Exam 2

In the eye, rods mediate __________, and cones mediate __________.

a. both mediate color only

b. both mediate movement only

c. light and movement, color vision

d. color vision, light and movement

e. both mediate color vision, light, and movement to the same extent

c

Low frequency sounds are processed in which part of the cochlea?

a. base

b. apex

c. mid-portion

d. all throughout the cochlea

e. none of the above

b

While going from the retina to the cortex, visual pathways innervate what part of the thalamus?

a. lateral geniculate

b. medial geniculate

c. superior colliculus

d. inferior colliculus

e. none of the above

a

What does the term "tonotopic representation" mean?

A) Only the auditory cortex has a systematic arrangment of neurons according to the frequency of the sound

B) The systematic arrangement of cells does not begin until the cochlear nucleus

C) Systematic arrangement of frequency extends all the way from the cochlea to the auditory cortex

D) Every location along the basilar membrane (within the cochlea) represents every frequency within the limits of human hearing (20-20kHz)

C

Why is neural activity in the left and right sides of the brainstem combined? (That is, why are there connections between nuclei on the left and right sides of the brainstem?).

A) The combination allows a sharper definition of which frequencies have entered the auditory system

B) The combination is importany for analysis of speech

C) The combination is simply because similar structures (such as the superior olivary nuclei) on either side of the brainstem tend to be connected

D) The combination allows cues such as timing and intensity differences entering the two ears to be used for localizing the source of sound in the environment

D

T or F: The auditory nerve and the primary auditory cortex are tonotopically organized.

T

T or F: During the endocochlear potential, depolarization occurs because of an outflow of Ca++ and K+ from the hair cell.

F

T or F: In the ear, the stapes makes contact with the round window.

F

T or F: Visual information about where an object is in space and in relation to your body is processed in the dorsal stream association area:

T

The Organ of Corti is located in the...

a. Scala Vestibuli

b. Scala Tympani

c. Scala Media

d. Cochlear Nucleus

e. None of the above

c

Where does hearing become binaural, in terms of the pathways from the cochlea to the cortex?

a. Cochlear Nucleus

b. Auditory Nerve

c. Superior Olive

d. Superior Colliculus

e. Thalamus

c

The cues required to localize sounds from either the left or right are processed in what nucleus of the auditory pathway?

a. Cochlear Nucleus

b. Superior Colliculus

c. Auditory Nerve

d. Medial Geniculate

e. Superior Olive

e

T/F: The auditory nerve and the primary auditory cortex are tonotopically organized.

True

T/F: During the endocochlear potential, depolarization occurs because of an outflow of Ca++ & K+ from the hair cell.

False

T/F: In the ear, the stapes makes contact with the round window.

False

T/F: Visual information about where an object is in space and in relation to your body is processed in the dorsal stream association area.

True

A person presents with flaccid weakness, decreased stretch reflexes and muscle fasciculation. Which of these would you expect to be damaged?

a. Sensory neurons

b. Basal ganglia

c. Lower motor neuron

d. Cerebellum

e. Upper motor neuron

c

This mediates internally generated movements:

a. Premotor area

b. Sensory area

c. Supplementary motor area

d. Primary motor area

e. Posterior parietal area

c

The cells that comprise the corticobulbar tract have their nuclei in:

a. The post-central gyrus

b. Ventrolateral thalamus (VL)

c. The caudate nucleus

d. The thalamus

e. The cortex

e

Which of these can exert an effect on a lower motor neuron?

a. Cortical cell

b. Fibers in the corona radiata

c. Peripheral sensory fiber

d. All of these can affect a lower motor neuron

e. fibers from sensory nuclei

d

This pathway influences background muscle activity & posture:

a. Vestigial cerebellar

b. Pontocerebellar

c. Vestibulocerebellar

d. Spinocerebellar

e. Cerebrocerebellar

d

The unit responsible for the contraction of a muscle is called the:

a. Actin

b. Myosin

c. Sarcomere

d. T-tubule

e. None of the above

c

T/F: A lesion to the right basal ganglia causes deficits in the right side of the body.

False

T/F: A lesion to the left cerebellum causes deficits to the left side of the body.

True

T/F: Swimming, chewing & swallowing are all examples of reflexive motor behaviors.

False

A child presents to the neurologist with a lateral strabismus of the left eye. She likely has an issue with the:

a. Right Cranial Nerve III

b. Left Cranial Nerve III

c. Right Cranial Nerve VI

d. Left Cranial Nerve VI

e. None of the above.

b

If you have a lesion in the left cerebral cortex motor areas for the face:

a. Drooping & weakness of the entire left side of the face

b. Drooping and weakness of the lower left side of the face

c. Drooping and weakness of the entire right side of the face.

d. Drooping and weakness of the lower right side of the face

e. None of the above

d

This motor only cranial nerve controls the tongue:

a. Trigeminal

b. Facial

c. Glossopharyngeal

d. Vagus

e. Hypoglossal

e

Which of these cranial nerves mediate a specialized sensory function?

a. Optic

b. Trochlear

c. Abducens

d. Oculomotor

e. Hypoglossal

a

A lesion to cranial nerve VIII would cause:

a. Visual deficits

b. Hearing deficits

c. Taste deficits

d. Tongue deficits

e. Olfactory deficits

b

Which of these cranial nerves controls vocal production?

a. VII

b. IX

c. X

d. XII

e. None of these

c

T/F: A lesion in the rostral spinal cord/caudal medulla can cause pain & temperature issues in the face.

True

T/F: During the endocochlear potential, depolarization occurs because of an influx of Ca++ and K+ in the hair cell.

True

In the eye, cones mediate:

a. Color vision

b. Light & movement

c. Light, movement, & color vision

a

High frequency sounds are processed in which part of the cochlea?

a. Base

b. Apex

c. Mid-portion

d. All throughout the cochlea

e. None of the above

a

T/F: The right side of the brain perceives the right side of the visual field.

false

A child presents to the neurologist with a lateral strabismus of the left eye. She likely has an issue with:

a. Right CNIII

b. Left CNIII

c. Right CNVI

d. Left CNVI

e. None of the above

b

This mediates goal directed movements:

a. Primary motor area

b. Supplementary motor area

c. Premotor area

d. Sensory area

e. Posterior parietal area

c

T/F: A lesion to the right cerebellum causes deficits in the left side of the body.

false

A person has trouble with voice & swallowing. Which cranial nerve do you suspect is impaired?

a. Trigeminal

b. Facial

c. Glossopharyngeal

d. Vagus

e. Hypoglossal

d

A person presents weakness, spasticity, and hyperactive reflexes. Which of these would you expect to be damaged?

a. basal ganglia

b. cerebellum

c. sensory neurons

d. upper motorneuron

e. lower motorneuron

d

The major input to the basal ganglia from the cortex is:

a. Globus pallidus internal segment

b. Globus pallid us external segment

c. Striatum

d. Substantia nigra

e. Nucleus accumbens

c

T/F: The pyramidal system sets background muscle activity on which skilled movements are performed.

false

This part of the sensorimotor system receives a copy of the motor plan and adjusts movements based on feedback from ongoing movement:

a. Thalamus

b. Premotor area

c. Basal ganglia

d. Cerebellum

e. Primary motor area

d

A person has trouble chewing and issues with pain/temperature to the face. Which cranial nerve do you suspect is impaired?

a. Trigeminal

b. Facial

c. Glossopharyngeal

d. Vagus

e. Hypoglossal

a

This part of the limbic system regulates memory:

a. Hippocampus

b. Amygdala

c. Septum Pallucidum

d. Hypothalamus

e. Thalamus

a

photons

light energy

the lends and cornea ________ the electromagnetic energy (photons)

refract (bend)

what converts electromagnetic energy to

retina (photoreceptors)

how do we see

The lens and cornea of the eye refract (bend) the electromagnetic energy (photons)

Electromagnetic energy is converted to nerve impulses by the retina (photoreceptors)

Transmission of the impulses from photoreceptors from retina to cortex (occipital cortex)

Perception of visual images is further processed by association areas

the eyeball is divided into the _______________ anterior and the ___________ ________________ posterior cavity

small

large round

anterior cavity

iris, cornea, lens, aqueous fluid similar to CSF

2 chambers: anterior and posterior

posterior cavity

area between lens and retina

filled with vitreous humor

vitreous humor

jelly-like substance that maintains normal intro-ocular pressure which prevents the eye from collapsing

formed early in life and is never replaced

pathways from the retina to the cortex

Light rays entering the eye are bent by the curvature of the cornea and accommodation of the lens and converge on rods and cones in the retina

The rods populate the peripheral regions of the retina and are sensitive to light and movement

The cones are mostly around the central retinal region where visual acuity is the highest

The photoreceptor cells convert light energy (photons) into nerve potentials that travel through the axons

cones

mediate color vision, which results from differential sensitivity of light wavelengths: red, green and blue

rods

night/low light vision

pathway from eye to cortex

The axons form the optic nerve cross at the optic chiasm and become the optic tract

The optic tract travels posteriorly and terminates in the lateral geniculate body of the thalamus

The geniculate projections called optic radiations travel through the brain to the occipital lobe

The visual cortex in the upper and lower banks of the calcarine fissure receives projections from both eyes

how light gets to the brain

begins with the cornea

iris

pupil

lens

retina

optic nerve

primary visual cortex

cornea

Clear, protective film covering your pupil

Keeps in the vitreous humor and slightly bends the light to direct it into your pupil

iris

Controls amount of light that passes through your pupil

pupil

Hole on surface of iris that light passes through

lens

Focuses light onto the retina

retina

3 layers

photoreceptor layer

bipolar cells

ganglion cells

photoreceptor layer

Signals colors

Gets color information from rods and cones

React to the absence of light

-Darker it is the more glutamate they release

bipolar cells

Transmits signals from the photoreceptors to the ganglion cells

ganglion cells

In the retina, the specialized neurons that connect to the bipolar cells; the bundled axons of the ganglion cells form the optic nerve.

**this blocks part of the retina and this creates a "blind-spot"**

optic nerve

passes through the "cerebral penduncle" to be interpreted into color, images, intensity and brightness

primary visual cortex

where all the visual information ends up

visual field

focused by the eye onto the retinal field

reversed

monocular vision

A portion of your visual field is only seen by one eye

binocular vision

The portions of your visual field that can be seen by both eyes

where do light rays merge into one object in the brain?

cortex

saccades

quick eye movements

parallel processing

capability to process visual components simultaneously

association processing

dorsal stream (where)

central stream (what)

dorsal stream (where)

Integrated motion, temporal and spatial

central stream (what)

Complex and cognitive aspects

Recognizing objects, faces, visual memory, reading

outer ear parts

pinna

external auditory meatus (ear canal)

tympanic membrane

middle ear parts

ossicles (malleus, incus, stapes)

inner ear parts

semicircular canals

cochlea

nerve to brain

cochlea

fluid filled chamber that is tonotopically organized

tonotopic organization

Different frequencies are represent in different areas of the cochlea

Hair length determines what tune it can/can't pick up

higher frequency

hair shorter near the base

List in order the structures that sound acts on, from external ear to inner ear.

External ear:

Gathers sound energy and focus it on the tympanic membrane (eardrum)

It amplifies sound to 2.5 kHz

Middle ear:

Vibrations vibrate the ossicles

The stapes vibrate the oval window which transmits vibrational energy to the fluids of the cochlea

Inner ear:

Converts energy to nerve impulses to be sent and interpreted by the brain

This is done by the cochlea

lower frequency

hair longer near the apex

what three structures make up to organ of corti?

sensory cells

supporting cells

auditory nerve fibers

sensory cells

1 row IHC

3 rows OHC

(receive efferent points from the brain)

stereocilia (stiff point at the tip of the OHC)

tip links (at tip of sterocilia)

What is the function of stereocilia?

height increases as they are arranged left to right

extend into indentations into tectorial membrane

based on the vibrations in the fluid of the cochlea they bend one way or another shifting and moving the tectorial membrane

depending on the direction of the bend the ion channels will open or close which increases/decreases the firing rate of the auditory nerve fibers

How do the membranes and hair cells work to convert sounds into electrical activity?

tip links translate hair bundle movemnt into a receptor potential

when hair bundles are shifted to the right ion channels open which causes an influx of potassium ions and depolarization of the HC which would lead to an influx in Ca2+ ions from calcium gated channel to open at the base of the hC, this triggers NTs to go into the synapse from the base of the HC, the NTs stimulate the afferent nerve fibers which form part of the auditory nerve and the signal is sent to the brain

what is the resting membrane potential of the HC?

150mV

what ions flow to depolarize the membrane?

potassium

where is the auditory cortex found?

the posterior superior temporal gyrus

BA: 41, 42, 22

does the primary auditory cortex have tonotopic organization?

yes, lower frequency sounds are anterior and higher frequency sounds are posterior

binaural hearing

hearing with two ears

ITD

IID

Interaural Time Delay (ITD)

there is a time difference in hearing with two ears, teh ear closer receives auditory stimuli sooner than ear further

the time difference helps with sound localization

Interaural Intensity Difference (IID)

due to dampening (caused by our own heads) there is an intensity difference in one ear compared to the other depending on where exactly the sound stimuli is coming from

makes it easier to locate high frequency sounds compared to low frequency sounds

pathway of electrical auditory stimuli in the brain

spiral ganglia

cochlear nuclei

superior olivary complex

lateral lemniscus

inferior colliculus

thalamus

medial geniculate body

auditory cortex

where in the brain is binaural hearing from both ears shared?

superior olivary complex

Automatic brainstem response testing (ABR testing)

measures the different "stops" the electrical stimuli takes to the brain

peaks show each stop

can be done with otoacoustic emissions test

used to refer a patient for further auditory testing