AUDITORY SYSTEM

Question 1

PINNA

Answer 1

outer ear important for sound localisation

Question 2

MIDDLE EAR

Answer 2

eardrum (tympanic membrane) + ossicles

Question 3

WHAT ARE OSSICLES OF EAR

Answer 3

small bones that conduct sound vibrations from eardrum to inner ear

malleus, incus + stapes

Question 4

WHAT DOES AUDITORY TUBE DO?

Answer 4

keeps air pressure equal on both sides of eardrum

links nasopharynx to middle ear

Question 5

INNER EAR CONSISTS OF

Answer 5

cochlea + vestibular apparatus (SSC, utricle + saccule)

Question 6

COCHLEA

Answer 6

propagates mechanical signals as waves in fluid + membranes

converts them to nerve impulses which are transmitted to the brain

Question 7

ORGAN OF CORTI

Answer 7

contains the cells responsible for hearing - the hair cells

located in cochlea

Question 8

VESTIBULAR SYSTEM

Answer 8

sensory system that provides brain with info about motion, head position + spatial orientation

Question 9

EXTERNAL AUDITORY MEATUS (AUDITORY CANAL) PASSES THROUGH WHAT?

Answer 9

temporal bone

Question 10

WHAT HELPS MAINTAIN PROPER AIR PRESSURE IN MIDDLE EAR?

Answer 10

eustachian tube (auditory)

Question 11

ENDOLYMPH

Answer 11

located in membranous labyrinth of inner ear

fluid bathes sensory cells to allow them to function normally

Question 12

THE ROUND WINDOW CONNECTS TO WHAT?

Answer 12

scala tympani

Question 13

PATHWAY LEADING TO PERCEPTION OF SOUND

Answer 13

tympanic membrane -> ossicles

-> perilymph -> endolymph -> hair cells

Question 14

A REFLEX REACTION TO LOUD SOUNDS PREVENTS DAMAGE TO INNER EAR DUE TO CONTRACTION OF WHAT?

Answer 14

tensor tympani (dampens loud sounds) + stapedius muscles (stabilises stapes)

Question 15

OVAL WINDOW CONNECTS TO WHAT?

Answer 15

stapes

scala vestibuli begins at oval window

Question 16

PITCH

Answer 16

frequency of sound vibration

Question 17

PERILYMPH

Answer 17

fluid between membranous labyrinth of ear + bone which encloses it

Question 18

HIGH INTENSITY SOUNDS CAN CAUSE DEAFNESS AS THEY ARE MOST DAMAGING TO WHAT?

Answer 18

hair cells of the organ of corti

Question 19

BASILAR MEMBRANE OF COCHLEA IS LOCATED BETWEEN WHAT?

Answer 19

scala tympani + scala media

Question 20

WHERE IS ORGAN OF CORTI LOCATED?

Answer 20

scala media

Question 21

VESTIBULAR APPARATUS CONSISTS OF WHAT?

Answer 21

vestibule (utricle + saccule)+ semicircular canals

Question 22

WHAT RECEPTORS ARE ASSOCIATED WITH THE SEMICIRCULAR CANALS?

Answer 22

crista ampullaris - sensory organ of rotation

Question 23

WHAT PART OF THE BASILAR MEMBRANE VIBRATES TO HIGH FREQUENCY?

Answer 23

base of membrane - shorter fibres

Question 24

LOW FREQUENCY SOUNDS LOCALISE WHERE?

Answer 24

at the apex of cochlea where there are longer fibres

Question 25

LATERAL VESTIBULOSPINAL TRACT

Answer 25

starts in lateral vestibular nucleus and descends the length of spinal cord

IPSILATERAL

pathway helps us walk upright

Question 26

MEDIAL VESTIBULOSPINAL TRACT

Answer 26

starts in medial vestibular nucleus + extends through mid-thoracic levels of spinal cord

BILATERAL

affects head movements + helps integrate head and eye movements

Question 27

WHAT ARE OTOLITH ORGANS SENSITIVE TO?

Answer 27

acceleration - they thus detected direction + magnitude of gravity

detect linear movements, head tilts + body’s position with respect to gravity

Question 28

WHAT DO SEMICIRCULAR CANALS DETECT?

Answer 28

ROTATION

Question 29

DOES VESTIBULAR SYSTEM PROGRESS MORE RAPIDLY THAN THE SENSE OF HEARING?

Answer 29

yes

Question 30

WHAT ARE TWO OTOLITH ORGANS?

Answer 30

saccule + utricle

Question 31

WHAT MACULA IS MORE SENSITIVE TO HORIZONTAL + WHICH ONE VERTICAL ACCELERATION?

Answer 31

utricle - horizontal

saccule - vertical