Examination of Smell, Taste, and Hearing Flashcards
Where is the olfactory epithelium located at the mucous membrane lining of the nasal cavity?
Inferior portion of the cribriform plate at the ethmoidal plate
What cells are responsible for olfaction?
Bipolar sensory cells
What is the main relay station for olfaction?
Olfactory bulb
What are the 3 olfactory striae (axons of olfactory bulb)? Which of these striae is the most important for smelling bcos this is where smells are pereceived?
Lateral olfactory striae - most important
Intermediate olfactory striae
Medial olfactory striae
What CN can be stimulated if u use alcohol or perfume for CN exam?
CN V1 - opthalmic division of the trigeminal nerve
What are the 4 conditions that can affect CN I?
- Fractures of cribriform plate of ethmoid bone
- Hemorrhage at base of frontal lobes
- Meningitis or abscess of frontal lobe
- Hypophyseal tumors
What condition is noted in px with olfactory groove or sphenoid ridge masses (meningiomas) or space occupying lesions of the frontal lobe?
Foster-Kennedy syndrome
What condition is noted in px w/ olfactory groove or sphenoid ridge masses (menangiomas) or space in the lesions of the frontal lobe?
Foster-Kennedy syndrome
What are the clinical presentation of Foster-Kennedy syndrome?
Ipsilateral anosmia
Ipsilateral optic atrophy
CL papilledema -> affected visual pathway
What CN I disorder is caused by a rare mutation that presents with congenital anosmia and hypogonadotropic hypogonadism?
Kallman syndorme
What gene is affected/mutated in Kallman syndrome?
KAL 1 gene
What are the imaging findings seen in Kallman syndrome?
Complete agenesis of the olfactory bulbs and sulci, OR medial orientation of the sulfatory sulci
What are the causes of Anosmia in COVID-19?
- Direct affectation of the virus through the Transmural pathway
- Hematogenous spread: breaking through the BBB
WHere are taste cells located?
Within the tongue epithelium
What is the innervation of the Anterior 2/3 of the tongue?
Chorda tympani (branch of CN VII)
What is the innervation of the posterior 1/3 of the tongue?
Afferents of the petrosal ganglion: CN IX
What innervates the epiglottis and larynx?
SUperior laryngeal nerve
Explain the GUstatory pathway?
Afferent tracts enter the brainstem —> synapses with ROSTRAL NUCLEUS OF THE SOLITARY TRACT —> gives afferent fibers to the IPSILATERAL pontine taste area as the CENTRAL TEGMENTAL TRACT —> IL Ventral-posteromedial nucleus of the thalamus —> IL primary gustatory area —> L hypothalamus & amygdala —> emotions with diff tastes
What are the objects used in examination of Gustation?
Sugar & salt soln
Disposable cotton applicator
Sterile gauze
H2O for drinking and gargling
What are the main indicators of localization for gustatory pathway?
Loss of appetite, smell, or taste
Bell’s palsy or idiopathic peripheral facial palsy
What CN is usually affected by UL loss of taste & at what side?
Ipsilateral CN VII
What is the medical torm for loss of taste due to affectation of taste buds?
Ageusia