Physiology

Question 1

what is the role of the different parts of the ear

Answer 1

external ear - sound collector
middle ear - mechanical force amplifier
inner ear - sound transducer / analyser

Question 2

how is the eustachian tube opened

Answer 2

by tensor veil palatini and elevator palatine muscles

Question 3

what does dysfunction in the eustachian tube lead to

Answer 3

middle ear negative pressure

Question 4

what are the two openings of the cochlea to the middle ear called

Answer 4

oval window

round window

Question 5

what do the oval and round window allow

Answer 5

transmission of pressure wave in enclosed canal & vibration of the basilar membrane

Question 6

what is the inner ear composed of

Answer 6

curved spiral lamina

semicircular canals

Question 7

what does the membranous labyrinth of the inner ear contain

Answer 7

endolymph

Question 8

what are the two parts of the membranous labyrinth and what are they composed of

Answer 8

vestibular labyrinth
- saccule and utricle

cochlear labyrinth
- cochlear duct in the cochlea

Question 9

what are the parts of the cochlear

Answer 9

scala vestibuli
scala tympani
scala media

Question 10

where is the scala tympani in relation to the cochlear nerve

Answer 10

below it

Question 11

what is above the cochlear nerve

Answer 11

scala vestibuli

Question 12

what is the organ of corgi

Answer 12

receptor organ for hearing located in cochlear
depolarises and fires
stimulating VIIIth nerve and then the central pathways

Question 13

where is sound processed

Answer 13

superior temporal gyrus of the temporal lobe

Question 14

what contributes to balance

Answer 14

ears
eyes
proprioception
cardiac
central

Question 15

what can affect balance systems causing loss of balance

Answer 15

Ears - BPPV, Menieres/Migraine, AVN

Eyes - cataracts, DM

Proprioception - DM, arthritis, neurology

Cardiac - arrhythmias, postural hypotension

central - stress, migrane, space occupying lesion, MS

Question 16

what are the otolith organs and what are there functions

Answer 16

utricle and saccule

lend weight & due to gravity brain perceives movement when tilting head or travelling in elevator

Question 17

what is embedded in the gel membrane of the otolith organs

Answer 17

otoconia

- calcium carbonate crystals

Question 18

how are the semi-circular canals arranged

Answer 18

at 90 degrees of each other

Question 19

what sits in the ampulla of a semi-circular canals

Answer 19

Cupula

Question 20

what is the vestibule-ocular reflex

Answer 20

liquid pushes against cupula
side you are turning to increases in firing rate
side you are turning away from decreases in firing rate

Question 21

what is a vestibular schwannoma and what can it cause

Answer 21

Tumour of VIII nerve sheath (schwann) cells

Imbalance due to slowly progressive loss of function

Question 22

what are the receptors for taste and smell

Answer 22

chemoreceptors

Question 23

where are the receptors for taste and what do they consist of

Answer 23

taste buds

- sensory and support cells

Question 24

what is the life span of taste receptors cells and where are they made

Answer 24

10 days

basal cells within the taste buds

Question 25

where do the majority of taste buds sit

Answer 25

in the papillae in the tongue

Question 26

what are the 4 types of papillae on the human tongue

Answer 26

Filliform: most numerous – do not contain taste buds Fungiform - contain Taste buds Vallate - contain taste buds Foliate - contain taste buds

Question 27

what is the nerve supply of taste

Answer 27

VIIth CN (chorda tympani branch of CNVII) - anterior two-thirds of the tongue IXth CN - posterior third of the tongue Xth CN - areas other than tongue

Question 28

what are the abnormalities of taste

Answer 28

Ageusia (loss of taste function): Hypogeusia (reduced taste function) Dysgeusia (distortion of taste function)

Question 29

what can cause abnormalities of taste

Answer 29

Ageusia - nerve damage, local inflammation Hypogeusia - chemotherapy, drugs Dysgeusia - glossitis, gum infections, tooth decay

Question 30

where is smell processed

Answer 30

in the Olfactory mucosa

Question 31

where is the olfactory mucosa found

Answer 31

in the ceiling (dorsal roof) of the nasal cavity

Question 32

what are the 3 cells of the olfactory mucosa

Answer 32

olfactory receptor cells, supporting cells and basal cells (secrete mucus)

Question 33

what does each olfactory receptor composed off and what is its function

Answer 33

olfactory rod cilia project to the surface of the olfactory mucosa and odourants bind to the cilia

Question 34

what is the lifespan of olfactory receptors and what act as precursors for new olfactory receptor cells

Answer 34

2 months Basal cells

Question 35

what transmit smell information to the brain

Answer 35

olfactory bulbs

Question 36

what are abnormalities of smell

Answer 36

anosmia - inability to smell hyposmia - reduced ability to smell dysosmia - altered sense of smell

Question 37

what can cause abnormalities of smell

Answer 37

anosmia - viral infection, allergy, head injury hyposmia - early signs of Parkinson's dysosmia - hallucinations