Olfaction, Taste, Hearing & Equilibrium

Question 1

the auditory part of the labyrinth

Answer 1

cochlea

Question 2

otolith organs and the semicircular canals

Answer 2

form the vestibular part of the labyrinth.

Question 3

a perception of sound energy

Answer 3

Hearing

Question 4

Hearing involves two aspects:

Answer 4

identification of the sounds (what?) and their localization (where?).

Question 5

The specialized receptors for sound are located in the _______ inner ear.

Answer 5

fluid-filled

Question 6

The inside of the tympanic membrane is exposed to the atmospheric pressure through the ______ ______, which connects middle ear to the pharynx.

Answer 6

Eustachian tube

Question 7

________ opens the Eustachian tube and allows the pressure on the both sides of the tympanic membrane to equalize

Answer 7

Yawning

Question 8

transfers the vibratory movements of the tympanic membrane to the fluid of the inner ear.

Answer 8

The middle ear

Question 9

structures of the middle ear amplify the force of sound waves, resulting in _______ forces at the oval window

Answer 9

pressure

Question 10

Cochlea is divided into three compartments

Answer 10

scala media (endolymph), scala vestibular and scala tympani (perilymph).

Question 11

Basilar membrane bears the ______ of ______, the sense organ of hearing

Answer 11

organ of Corti

Question 12

•Protruding from surface of each hair cell are about 100 hairs, known as

Answer 12

stereocilia

Question 13

The stereocilia are mechanically embedded in the

Answer 13

tectorial membrane

Question 14

has a high [K+]

Answer 14

Endolymph

Question 15

displacement of stereo cilia toward the kinocilium open ________ cation channel.
K+ entry causes depolarization of hair cell membrane.
Leads to ____ entering, and _________ of neurotransmitter = depolization of auditory neuron

Answer 15

nonsleective
Ca
exocytosis

Question 16

Afferent fibers from spiral ganglion form, which joins vestibular nerve to become the vestibulocochlear nerve (VIII)

Answer 16

the auditory (cochlear) nerve.

Question 17

Sends information to other
cortical processing areas:
e.g. Wernicke’s area
(understanding of written and
spoken language)

Answer 17

Auditory cortex

Question 18

processes of acoustic signals to

distinguish if they are speech, music, or noise.

Answer 18

Wernicke’s area

Question 19

Occurs due to blockage of the ear canal with earwax, rupture of the tympanic membrane, middle ear infections with fluid accumulation, bony adhesions between the stapes and the oval window.

Answer 19

conductive deafness

Question 20

The defect can lie in the organ of Corti or the auditory nerves or, rarely, in the ascending auditory pathways or auditory cortex.

Answer 20

sensorineural deafnessa

Question 21

a degenerative, age-related process that occurs as hair cells “wear out” with use.

Answer 21

Neural presbycusis

Question 22

Decreased number of hair cells, loss of spiral ganglion, formation of reactive oxygen species

Answer 22

Amynoglycoside antibiotics

Question 23

Decreased number of hair cells, changes in mitochondrial function, direct cell death

Answer 23

Chemotherapeutic agents

Question 24

Reduction in endocochlear potential

Answer 24

Chemotherapeutic agents, diuretics, and aminoglycosides

Question 25

Disruption of endocochlear fluid homeostasis, disruption of endolymph homeostasis

Answer 25

Diuretics

Question 26

Decreased cochlear blood flow due to inhibition of prostaglandin synthesis

Answer 26

Quinine and salicylates

Question 27

Activation of NMDA receptors has been implicated in tinnitus induction

Answer 27

Quinine and salicylates

Question 28

although used alone cause only temporary hearing loss, they potentiate the toxicity of other ototoxic agents

Answer 28

Diuretics

Question 29

hearing loss is generally reversible and usually occurs only with high doses

Answer 29

Quinine and salicylates

Question 30

these drugs can cause permanent hearing loss

Answer 30

Amynoglycoside antibiotics

Question 31

may occur as a result of disorders in the middle or inner ear or along the central neuronal pathways.

Answer 31

Tinnitus

Question 32

treament of tinnitus

Answer 32

ignore sounds

Question 33

•Provides information essential for the sense of equilibrium and for coordinating head movements with eye and postural movements

Answer 33

Vestibular system

Question 34

Vestibular system consists of two sets of structures

Answer 34

semicircular canals and the otolith organs

Question 35

provide information about the position of the head relative to the gravity and detect changes in the rate of linear motionOtolith organs

Answer 35

Otolith organs

Question 36

detect rotational and angular acceleration or deceleration of the head, such as when starting or stopping spinning, or turning the head.

Answer 36

The semicircular canals

Question 37

Superior, horizontal and posterior canals hair cells are located in a swelling called the

Answer 37

ampulla.

Question 38

The cilia of the hair cells project into a gelatinous mass called the _______. Movements cause generation of receptor potentials in the hair cells

Answer 38

cupula

Question 39

the sensation that either the body or the environment are moving, when actually both are stationary = spinning sensation

Answer 39

Vertigo

Question 40

a sensation of lightheaded- | ness, faintness, or unsteadiness

Answer 40

Dizziness

Question 41

the most common cause of pathologic vertigo

Answer 41

Vestibular dysfunction

Question 42

Spatial orientation and posture are controlled by three sensory systems:

Answer 42

vestibular, visual and somatosensory; a mismatch between any of these can result in vertigo.

Question 43

an abnormality of the inner ear causing vertigo or severe dizziness, tinnitus, fluctuating hearing loss, nystagmus, and the sensation of pressure or pain in the affected ear

Answer 43

Ménière disease

Question 44

Ménière disease treatment

Answer 44

There is no cure, but the symptoms can be controlled by reducing the fluid retention through dietary changes (low-salt or salt-free diet, no caffeine, no alcohol) or with diuretics.

Question 45

Nausea and vomiting are caused by stimulation of the

Answer 45

vomiting center in the medulla

Question 46

Drugs used to prevent motion sickness suppress signals between vestibular nuclei and the vomiting center. They target

Answer 46

muscarinic and histaminic (H1) synaptic receptors

Question 47

a belladonna alkaloid, which acts by blocking cholinergic transmission from the vestibular nuclei to higher centers in the CNS.

Answer 47

Scopolamine

Question 48

primarily a H1-antagonist, but also has an antimuscarinic effect

Answer 48

•Dramamine (dimenhydrinate)

Question 49

an antihistaminic agent (marketed as "Dramamine II") less likely to cause drowsiness.

Answer 49

•Meclizine

Question 50

•Axons of the olfactory sensory neurons enter ______ _____, where they synapse with second-order neurons

Answer 50

olfactory bulb

Question 51

From olfactory bulb the information is transmitted to higher brain structures including the (3)

Answer 51

piriform cortex, hippocampus and amygdala

Question 52

can result from nasal congestion, damage to the olfactory nerves, tumors (neuroblastomas, meningiomas), infections, overuse of nasal vasoconstrictors, smoking.

Answer 52

Anosmia and hyposmia

Question 53

_________ disease can also damage the olfactory nerves

Answer 53

alzheimers

Question 54

a homeopathic intranasal substance marketed to alleviate cold symptoms, has been implicated in olfactory dysfunction

Answer 54

Zicam

Question 55

Taste receptors are located on projections from the surface of the tongue called

Answer 55

papillae

Question 56

Each papillae has numerous ______, which open onto the surface of the tongue at a small depression called the _______

Answer 56

taste buds | taste pore

Question 57

•Each taste bud contains approximately 100 taste receptor cells with

Answer 57

microvilli.

Question 58

Sour taste is caused by

Answer 58

acids, which contain free H+.

Question 59

______ substances use intracellular second messengers: binding of glucose » cAMP production» depolarization of the receptor cell membrane.

Answer 59

sweet

Question 60

receptors use more than one transduction mechanism depending on the tastant: direct binding to K+ channel and changes in second messengers.

Answer 60

bitterness

Question 61

taste is elicited by activation of ionotropic glutamate receptor, which mediates depolarization.

Answer 61

Umami taste