SMELL Flashcards
___________maintain the electrolyte (particularly K) levels in
the extracellular milieu;
sustentacular cells
________, which are stem
cells and the source of both the olfactory and sustentacular
cells during regeneration
basal cells
____________ are very fine (0.2 mm in diameter) unmyelinated
fibers that converge to form small fascicles enwrapped
by Schwann cells that pass through openings in the
cribriform plate of the ethmoid bone into the olfactory
bulb
olfactory
fila,
These molecules are thought to
prevent the intracranial entry of pathogens via the olfactory
pathway
immunoglobulins
A and M, lactoferrin, and lysoenzyme as well as
odorant-binding proteins
The medial stria contains fibers from the ____________. these pass to the opposite side via the anterior commissure.
Fibers in the _________originate in the olfactory bulb, give off collaterals to the anterior perforated substance, and
terminate in the medial and cortical nuclei of the ___________ (also referred
to as the lateral olfactory gyrus).
anterior olfactory nucleus;
lateral stria
amygdaloid
complex and the prepiriform area
The transduction of odorant stimuli to electrical
signals is mediated in part by a _______
guanosine triphosphate
GTP)-dependent adenylyl cyclase (“G protein”
The _______ also participates in chemesthesis
through undifferentiated receptors in the nasal
mucosa. These receptors have little discriminatory ability
but a great sensitivity to irritant stimuli
trigeminal system
clinical manifestations of olfactory disease
- _________________loss or reduction of the sense
of smell (anosmia, hyposmia) or, rarely, increased
olfactory acuity (hyperosmia) - __________________ distortions or illusions of
smell (dysosmia or parosmia) - _____________caused by temporal
lobe disorders or psychiatric disease - _____________(olfactory
agnosia)
Quantitative abnormalities:
Qualitative abnormalities:
Olfactory hallucinations and delusions
Higher-order loss of olfactory discrimination
__________
substances are unsuitable stimuli because they do not test
the sense of smell but have a primary irritating effect on
the mucosal-free nerve endings of the trigeminal nerves
Ammonia and similar pungent
Unique features of this test are a means for detecting
malingering and amenability to self-administration
scratch-and-sniff test
The loss of smell usually falls into one of three categories:
__________(in which odorants do not reach the olfactory
receptors), olfactory neuroepithelial (caused by destruction
of receptors or their axon filaments), and central (olfactory
pathway lesions
nasal
_________ is probably the most frequent cause of ANOSMIA
Heavy smoking
Biopsies of the olfactory mucosa
in cases of allergic rhinitis have shown that the sensory
epithelial cells are still present, ______
but their cilia are deformed
and shortened and are buried under other mucosal cells.
Nutritional and metabolic diseases such as __________
(Wernicke disease), ________, adrenal
and perhaps __________ cirrhosis, and chronic
renal failure may give rise to anosmia, all as a result
of ________
thiamine deficiency
vitamin A deficiency
thyroid insufficiency,
sensorineural dysfunction
Anosmia has been found in some patients with
temporal lobe epilepsy and particularly in such patients
who had been subjected to ______
anterior temporal lobectomy
The term ___________ has been applied to an
unusual olfactory phenomenon in which a person with
normal olfactory acuity for most substances encounters a
particular compound or class of compounds that is odorless
to him, although obvious to others. In
specific anosmia
Pathophysio of anosmia in PD
has been that Lewy bodies in particular are
caused by a pathogen that enters through the peripheral
olfactory system and proceeds centrally through the
medial temporal lobe
Olfactory hallucinations and delusions may occur in
conjunction with ________ but one should
also consider the possibility of a late-life depression.
Alzheimer dementia,
olfactory dysfunction in patients with the alcoholic form of
Korsakoff psychosis;
Loss of O l fa ctory D i sc r i m i n at i o n
O lfa cto ry Ag n o s i a
The ________ are round or oval structures,
each composed of up to 200 vertically oriented receptor
cells arranged like the staves of a bar
taste buds
The superficial
portion of the bud is marked by a small opening, the
_______, which opens onto the mucosal surface
taste pore or pit
u mani, signifying a savory taste-the taste of _______
glutamate,
aspartate, and certain ribonucleotides
A G-protein transduction system _________, similar
to the one for olfaction, has been found to be operative
in signaling taste sensations in the tongue receptors
(gustducin)
The receptor cells of the taste buds have a brief
life cycle__________, being replaced constantly by
mitotic division of adjacent basal epithelial cells
(about 10 days)
From the posterior one-third of the tongue, soft palate,
and palatal arches, the sensory taste fibers are conveyed
via the __________
to the nucleus of the tractus solitarius
glossopharyngeal (IX) nerve and ganglion nodosum
The gustaton; n ucleus is situated in the
rostral and lateral parts of the nucleus tractus solitarius,
which receive the special afferent (taste) fibers from the
___________ nerves
facial and glossopharyngeal
Special types of apparatus
___________ have been devised for the measurement
of taste intensity and for determining the detection
and recognition thresholds of taste and olfactory stimuli
(electrogustometers)
Apart from the loss of taste sensation that accompanies
normal aging, _______ is probably the most common
cause of impairment of taste sensation
smoking
Taste is frequently
lost over the anterior two-thirds of one side of the
tongue in cases of mundane_____
Bell palsy,
A permanent decrease in the acuity of taste and
smell (hypogeusia and hyposmia), sometimes associated
with perversions of these sensory functions (dysgeusia
and dysosmia), may follow ______
influenza-like illnesses
drugs that alter taste sensation
Lipid-lowering drugs, antihistamines, antimicrobials,
antineoplastics, bronchodilators, antidepressants, and
antiepileptics
Oropharyngeal tumors may, of course, abolish taste by invading the chorda ________
tympani or lingual nerves
and basal skull
Unilateral______
and ___________, however, have both been
associated with contralateral impairment of taste sensation
in rare cases.
thalamic
parietal lobe lesions
a gustatory aura occasionally
marks the beginning of a seizure originating in
the________ or in the _________
frontoparietal (suprasylvian) cortex
uncal
region.
Gustatory hallucinations were more
frequent with _______, and in half of the
cases, the gustatory aura was followed by a convulsion
right-hemisphere lesions
mainly in postmenopausal women and is characterized
by persistent, severe intraoral pain (particularly of the
tongue)..
Many such patients that we have encountered appeared to have a________ but they responded
only inconsistently to administration of antidepressants
_____ may be useful, and capsaicin has been tried
with uncertain results.
Burning Mouth Syndrome
depressive illness,
Clonazepam
