Physiology

Question 1

What dictates the pitch and the volume of sound?

Answer 1

pitch- frequency of sound

volume- amplitude of sound

Question 2

What frequency can humans hear?

Answer 2

20Hz-20000Hz

Question 3

What part of the anatomy focusses the sound?

Answer 3

• tympanic membrane to oval window

- malleus handle to incus long process

Question 4

What are the parts of the cochlea?

Answer 4

the scala media is suspended between the scala tympani and the scala vestibuli

Question 5

What are perilymph and endolymph most like?

Answer 5

perilymph = ECF
endolymph = ICF

Question 6

How is the cochlea arranged in terms of frequency?

Answer 6

tonotopically so each frequency of sound vibrates a different part of the basilar membrane

Question 7

What is the pneumonic for auditory brainstem response tracking?

Answer 7

Eight cranial nerve
Cochlear nucleus
Olivary complex (superior)
Lateral lemniscus
Inferior colliculus
E.coli

Question 8

What is the area of the brain for hearing and speech?

Answer 8

left posterior superior temporal gyrus

Question 9

What is the resting state for the cartilaginous portion of the Eustachian tube and how is it opened or closed?

Answer 9

• resting is closed

- can be opened by tensor veli palatini and levator palatine muscles

Question 10

What are the milestones for hearing in utero?

Answer 10

In utero: 18 weeks a foetus can hear

In utero: 26 weeks a child kicks and responds to sound

Question 11

What are the milestones for hearing/speech?

Answer 11

3 months: cooing, recognise mother voice
6 months: babbling, turns to sound
12 months: simple noises
12-24 months: syllable deletion and simplification, substitutions
18 months: 20-50
24 months: 50+ words, understands questions

Question 12

What are the features of Romberg’s test?

Answer 12

• balance with eyes closed
• input is vestibular
• output is vestibulospinal

Question 13

What supplies the SCCs, utricle and saccule?

Answer 13

• SVN supplies the lateral, anterior SCC and utricle

- IVN supplies posterior SCC and saccule

Question 14

What are the features of the hair cells in inner ear?

Answer 14

• Kinocilium is the longest
• Stereocilia are the rest
• deflection towards increases APs
• deflection away decreases APs

Question 15

How do the SCCs work with head movement to move eyes?

Answer 15

• cupula senses movement by perilymph movement
• excitation of muscles on the side of movement
• inhibition of the other side
• input is vestibular
• output is vestibulo-ocular

Question 16

What happens if there is a lesion on the left to eye movement?

Answer 16

if you lose left function, the eyes are moving to the left and then fast back to the right

Question 17

What are the features of taste receptors?

Answer 17

• chemoreceptors
• lifespan of 10 days
• pore and protective microvilli
• synapse with afferent nerve fibres

Question 18

Where are the taste buds on the tongue?

Answer 18

fungiform, vallate and foliate papillae

Question 19

What are the nerve outputs for taste?

Answer 19

• 7th CN for the anterior 2/3rds tongue vie chord tympani
• 9th CN for posterior 1/3rd tongue
• 10th CN for everywhere else

Question 20

What are the five tastes?

Answer 20

bitter, sour, salty, sweet and umami

Question 21

What are aguesia, hypoguesia and dysguesia?

Answer 21

• Aguesia is loss of taste function eg nerve damage, radiation, tobacco
• Hypogeusia is reduced taste function eg chemotherapy
• Dysgeusia is distortion of taste function eg chemotherapy, metronidazole, infections

Question 22

How does smell work?

Answer 22

• sensed in the olfactory mucosa
• afferent fibres of olfactory nerve run through cribriform plate of ethmoid bone and enter olfactory bulbs
• to olfactory tracts to temporal lobe
• smell must be volatile and water-soluble

Question 23

What are anosmia, hyposmia and dysosmia?

Answer 23

Anosmia is inability to smell eg allergy, infection, polyps
Hyposmia is reduced ability to smell eg above or Parkinson’s
Dysosmia is altered sense of smell

Question 24

What is congenital deafness in a 2 year old most likely to be?

Answer 24

cytomegalovirus in the mother in early pregnancy