Neuro Test 3

Question 1

At what point in the sound wave is intensity the highest?

Answer 1

during the peak compression in each cycle where there is increased density of the air

Question 2

What is the perceptual correlate of intensity (aka amplitude)?

Answer 2

loudness

Question 3

How is sound intensity usually expressed? What is the formula to convert the pressure of a sound wave to this unit?

Answer 3

decibels of sound pressure level. dB SPL = 20log10[P1/P2] P2= reference pressure of 20 X 10 to -6 newtons/m2 (this is the threshold pressure for human hearing at 1000 Hz).

Question 4

What are the 2 properties of sound that are decoded by the auditory system?

Answer 4

intensity and frequency

Question 5

What is frequency?

Answer 5

the number of times per second that a sound wave reaches the peak of rarefaction (or compression)

Question 6

What is the term for increased air density?

Answer 6

compression

Question 7

Formula for the wavelength of a sound wave?

Answer 7

wavelength = velocity/frequency. units are Hertz, cycles per second

Question 8

What is the auditory threshold?

Answer 8

the smallest dD SPL that a subject can detect

Question 9

How is auditory threshold determined for individuals?

Answer 9

audiologists quantify hearing loss by determining for each ear, and at different frequencies the smallest dB SPL that a subject can just detect

Question 10

What is the term for a loss of high frequency hearing?

Answer 10

presbycusis

Question 11

Why does presbycusis make it really hard to understand speech?

Answer 11

because fricative consonants (such as t, p, s, f) are distinguished by high frequency components that fall in the upper end of the human audiogram

Question 12

Why do we need a middle ear in between air-filled outer ear and the fluid-filled inner ear?

Answer 12

because direct communication with the middle ear would result in a very inefficient transfer of acoustic energy from air to fluid

Question 13

Why does the energy of sound travel through water less well than air?

Answer 13

because water is more resistant to movement than air, aka impedance of water is bigger than impedance of air

Question 14

What are the two ways in which the middle ear alleviates mismatch between air and fluid?

Answer 14

1) P = F/A. area of tympanic membrane is 20X that of stapes footplate. 2) orientation of middle ear bones confers a levering action resulting in a larger force.

Question 15

What is the medical term for ear cannal?

Answer 15

external auditory meatus

Question 16

What middle ear bone contacts the tympanic membrane?

Answer 16

malleus

Question 17

What middle ear bone contact the oval window?

Answer 17

stapes

Question 18

What drugs are ototoxic?

Answer 18

aminoglycoside antibiotics, diuretics, aspirin, cancer therapy drugs

Question 19

If a patient has conductive hearing loss, will putting the tuning fork to their ear overcome their hearing loss?

Answer 19

yes, because of bone conduction

Question 20

What is the primary stimulus attribute that is mapped along the cochlea?

Answer 20

frequency

Question 21

What is the major cause of congenital deafness?

Answer 21

mutation is connexin 32 –> no active K+ pumping into endolymph

Question 22

what is the term for impaired recent memory and deficient new learning?

Answer 22

amnesia

Question 23

What is the term for the acquired disorder of language resulting from damage to the brain areas subserving linguistic capacity?

Answer 23

aphasia

Question 24

Where will a pt with conduction aphasia have a lesion?

Answer 24

in the arcuate fasciculus

Question 25

Where will a pt with global aphasia have a lesion?

Answer 25

in the perisylvian region

Question 26

What is the most sensitive indicator of language impairment?

Answer 26

naming

Question 27

Damage to what area of the brain causes deficits in repetition?

Answer 27

the perisylvian zone, which includes Wernicke’s and Broca’s areas, the arcuate fasciculus

Question 28

What two aphasias (of the LOs) have fluent spontaneous speech?

Answer 28

Wernicke’s and conduction aphasia

Question 29

How do you distinguish between Wernicke’s and conduction aphasia?

Answer 29

Conduction aphasia pts have auditory comprehension, while pts with Wernicke’s do not

Question 30

What two aphasias (of the LOs) have nonfluent spontaneous speech?

Answer 30

Broca’s and global aphasias.

Question 31

How to distinguish between Broca’s and global aphasia?

Answer 31

Broca’s aphasia pts have auditory comprehension, but global aphasia pts do not.

Question 32

Hemineglect of the left side is caused by damage to the posterior parietal cortex of which side?

Answer 32

the right typically

Question 33

What is the name of a motor neuron and the muscle fibers it innervates?

Answer 33

motor unit

Question 34

What is the hallmark of ALS?

Answer 34

degeneration of alpha motor neurons –> progressive weakness and wasting of skeletal muscles

Question 35

What is the population of alpha motor neurons that innervate muscle fibers within a single muscle referred to as?

Answer 35

motor neuron pool

Question 36

What size motor neuron will innervate a small number of muscle fibers?

Answer 36

a small one!

Question 37

What is the systemic recruitment of smaller-to-larger motor units referred to as?

Answer 37

the size principle

Question 38

What are the two factors of motor units that enable them to be recruited in a small-to-large manner?

Answer 38

1) small motor neurons have high input resistances because of fewer channels in the membrane. V = IR, so they get a relatively larger voltage change. activated sooner.
2) fatigability

Question 39

What types of muscles (in terms of fatigability) do large alpha motor neurons innervate?

Answer 39

fast twitch glycolytic muscles that generate large forces but are quick to fatigue. actions such as running and jumping. aka fast fatigable FF motor units

Question 40

What types of muscles (in terms of fatigability) do small alpha motor neurons innervate?

Answer 40

slow twitch muscle fibers forming a (S) slow motor unit that fatigues very slowly for actions such as posture

Question 41

What types of muscles (in terms of fatigability) do medium sized alpha motor neurons innervate?

Answer 41

fast twitch oxidative fibers and comprise fast fatigue resistant motor units, which have an intermediate size and force generation capacity

Question 42

How can exercise alter the motor unit phenotype?

Answer 42

can change the motor unit from fast to slow, effectively slowing fatigability and increasing endurance capacity

Question 43

Where are the motor systems organized somatotopically?

Answer 43

in the spinal cord (all along the rostro-caudal axis as well) and the motor cortex

Question 44

Where do the neurons that innervate the lateral musculature reside in the spinal cord?

Answer 44

laterally