Clinical Flashcards
mild hearing loss audiogram score
20-40
moderate hearing loss audiogram score
40-60
severe hearing loss audiogram score
60-90
profound hearing loss audiogram score
> 90
transduction
conversion of mechanical stimuli into neural stimuli by the middle ear
outer hair cells
receive sound
inner hair cells
convert sound into mechanical energy
base of cochlea
high frequency sound
apex of cochlea
low frequency sound
primary auditory cortex of brain
superior temporal gyrus
OAE
otoacoustic emissions - produced by normal hair cells and absent in deafness
ABR
auditory brainstem response
superior vestibular nerve supplies
lateral semicircular canal, anterior semicircular canal and utricle
inferior vestibular nerve supplies
posterior semicircular canal and saccule
vestibulo-occular reflex
eyes stay fixed on a certain point when the head moves
motor output to the head, neck and back for posture
vestibulospinal tract
motor output to eyes for gaze stabilisation
medial longitudinal fascicles and ocular muscles
output to cerebrum for awareness
medial lemniscus and thalamus
components of taste buds
sensory cells and support cells (arranged like orange slices)
lifespan of taste receptor cells
10 days
taste receptor cells replaced from
basal cells within taste bud
where are taste buds found?
tongue, epiglottis, pharynx, palate
afferent taste fibres on the anterior 2/3 of the tongue reach the brainstem via…
CN VII
afferent taste fibres on the posterior 1/3 of the tongue reach the brainstem via…
CN IX
afferent taste fibres on areas other than the tongue reach the brainstem via…
CN X
bitter stimulants
diverse group of tastants e.g. alkaloids, poisonous substances, toxic plant derivatives
salty stimulants
Cl-
sweet stimulants
configuration of glucose
umami stimulants
amino acids (especially glutamate)
sour stimulants
H+
two main neural nasal systems
olfactory system (CNI) - mediates common odours
trigeminal somatosensory system (CNV) - mediates chemical and non-chemical stimuli e.g. irritation, burning, and can also play a role in coughing, spluttering and sneezing
what cells secrete mucous in the olfactory epithelium?
duct cells of bowman’s glands
lifespan of olfactory receptors
2 months
bacteria associated with acute otitis media
strep pneumoniae, haemophilus influenzae, moxarella catarrhalis
bacteria associated with chronic otitis media
staph aureus, pseudomonas aeruginosa, fungal
4 cranial nerves associated with oral phase of swallowing
CNV3, CNVII, CNX, CNXII
palatal rugae cells…
keratinised stratified squamous epithelium
two nerves that supply the hard palate
incisive branch of nasopalatine nerve, greater palatine nerve
nerve that supplies the soft palate
lesser palatine nerve
duration of pharyngeal phase of normal swallowing
<1 second
hyoid bone is dragged anterosuperiorly
hyolaryngeal elevation
muscles associated with hyolaryngeal elevation
suprahyoid, longitudinal pharyngeal muscles
upper oesophageal sphincter
cricopharyngeus
duration of oesophageal phase of normal swallowing
8-20 seconds
where does the retropharyngeal space connect with?
mediastinum
which two cranial nerves form the pharyngeal plexus?
CNIX and CNX
when does pharyngeal arch 1 develop?
day 22
when do pharyngeal arches 2 and 3 develop?
day 24
when do pharyngeal arches 4 and 6 develop?
day 29
component of pharyngeal apparatus made from mesenchymal tissue
core pharyngeal arch
component of pharyngeal apparatus made from ectoderm
external pharyngeal cleft
component of pharyngeal apparatus made from endoderm
internal pharyngeal pouch
cells that make up the tonsils…
specialised squamous epithelium
cells that make up the adenoids…
ciliated pseudostratified columnar epithelium
