STUFF TO KNOW!!! Flashcards
receptors for state and smell
chemoreceptors
lifespan of taste buds
10 days (basal cells)
afferent taste of anterior 2/3 tongue
CNVII
afferent taste of posterior 1/3 tongue
CNIX
loss of taste function
aguesia
lifespan of olfactory cells
2 months (basal cells)
inability to smell
anosmia
humans perceive what sound
20-20,000Hz
intensity/loudness of sound
amplitude
part of ear embedded in temporal bone
inner 2/3rds
middle ear location
mastoid process
Ossicular chain amplifies sound how much greater
22x
inner ear components
cochlea + vestibular system = Otic capsule
type of lymph in membranous labyrinth
perilymph
6 specialised receptor organs in the membranous labyrinth
organ of corti, macuale of utricle + saccule, Cristae of 3 semicircular canals
3 chambers of cochlea
scala vestibule, scala tympani, scala media (has endolymph others have perilymph)
Hair cell function
transduction - bending force goes to electrical impulse
The organ of Corti here depolarises and fires - stimulating the VIIIth nerve and then the central pathways. >
Culminating in activity in superior temporal gyrus
Utricle and saccule detects what planes of motion
all planes
moving head right would cause right excitation and left inhibition. So brain knows rotational movement to right.
This is an example of …
Paired function
eyes making repetitive, uncontrolled movements
nystagmus
visual fields appear to oscillate > vertigo
Oscillopsia
person feels as if they or the objects around them are moving when they are not, often accompanied with horizontal nystagmus.
Vertigo
Vestibular Schwannoma
benign tumour of schwann cells in vestibular portion of CNVIII [most common at cerebrobellopontine angle] If young invx NF type2. Think elderly + unilateral headache.
Cholesteatoma
presence of squamous epithelium in middle ear (usually from chronic Otitis media and perforated tympanic membrane)
Rhinitis + Sinusitis
common cold, allergy
Nasal Polyps
aspirin sensitivity, allergy, nickel exposure, infection. If young consider CF.
GPA
autoimmune (white + >40yrs). Small vessel vasculitis to resp. tract and kidneys. ANCA+ve
Laryngeal Polyps
reactive change in mucosa due to vocal abuse, infection, smoking and occasionally hypothyroidism.
Larynx Ulcers
benign response to injury (e.g vocal abuse, GORD)
Papillomas
HPV exposure (type 6+11)
Paraganglioma
tumours arising in clusters of neuroendocrine cells throughout the body.
most common site for tumours of salivary galnds
Parotid (largest)
Pleomorphic adenoma
most common tumour (females >60) in parotid
Warthin’s tumour
2nd most common (males >50) in parotid