Practical lesson tasks (General Medicine, Pediatrics)
Physiology of analyzers. Auditory, vestibular, gustatory, olfactory analyzers
PART 1
Task №1. Analyzer parts. Fill in the table, specify the structures related to the relevant parts of
these analyzers
Parts
Analyzer
Peripheral
Conduction
Central
Auditory
sensory hair cells in organ Cochlear Spiral ganglion - cochlear temporal
lobe
of
of Corti (located in internal nerve (part of
cerebral cortex.
ear).
cranial nerve VIII) - medulla
(cochlear nuclei) - auditory pathway
- superior olivary nucleus - inferior
colliculus - medial geniculate
nucleus
Vestibular
– bony labyrinth located in – branches of vestibulocochlear postcentral gyrus, lower
temporal bone (otolith nerve (cranial nerve VIII)
part.
organs and
medulla (nucleus of Schwalbe,
three semicircular canals) Bekhterev, Deiters, Manakov)
spinal cord,
cerebellum, midbrain (oculomotor
nuclei), autonomic ganglions,
reticular
formation
Olfactory
Olfactory receptors
Olfactory nerve - pierce the inner part of temporal
are situated in olfactory cribriform plate of ethmoid bone
lobe, hippocampus.
mucus
- olfactory bulb (second order
membrane, which is the neuron) - olfactory tract (tractus
modified
olfactorius) mucus membrane that lines olfactory center.
upper
part of nostril.
Taste
Taste receptors – taste buds, Receptors – chorda tympani fibers postcentral gyrus, lateral
each taste bud
of
facial
nerve
(VII), sulcus.
contains 2-6 receptors and glossopharyngeal nerve fibers
basal cells.
(IX) -nucleus of tractus solitarius in
Most of the taste buds are the medulla oblongata (first order
present on the
neuron) papillae of tongue. Taste medial leminiscus (second order
buds are also situated
neuron) - posteroventral nucleus of
in the mucosa of epiglottis, thalamus (third
palate, pharynx
order neuron).
and the proximal part of
esophagus.
Task №2. The structure and function of the ear. Fill the table
Structures
Outer ear
auricle, external auditory canal,
tympanic membrane
Middle ear
tympanic cavity, and its little
bones auditory ossicles :
malleus, incus, stapes and
Function
receives
the sound waves then transmit it
to tympanic membrane
conduct
sound vibration from tympanic
membrane to internal ear
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Inner ear
Eustachian tube
Labyrinth (cochlea)– bone canal makes of two
and a half turn.
Two membranes divide bone canal:
Vestibular membrane (Reissner membrane)
Basilar membrane
Scalae of spiral canal of cochlea:
Scala vestibular;
Scala media;
Organ of Corti is located basilar membrane of scala
media.
Scala tympani.
pivotal roles in maintaining
postural balance and visual
focus on a single object (gaze
fixation).
Task №3. . Transmission of sound vibrations. find the correct sequence
1
sound
11
deformation of hair cells upon contact with the integumentary membrane
8
oscillations of the perilymph of the upper and lower channels
3
eardrum
12
occurrence of receptor potential
5
incus
13
AP
10
vibrations of the hair cells of the main membrane
9
middle channel endolymph oscillations
7
oscillation oval window
4
malleus
14
nerve fibers
2
external auditory canal
6
stapes
Task №4. Vestibular apparatus. Fill the table
Element of the vestibular
apparatus
Location
Sensitive to ...
Otolithic apparatus
Both of them – otolith apparatus
(receptor cells, particles of calcium
carbonate)
movements like linear
acceleration and head tilts
hair cells receptors
Three semicircular canals, their
end is enlarged - ampulla.
In the ampulla – receptive hair
cells
Directional sensitivity of
individual vertebrate hair cells to
controlled deflection of their hair
bundles
Task №5. Taste disorders. Fill the table
Name of the disorder
Ageusia
taste loss
hypergeusia
hypergeusia
hypogeusia
parageusia
reduced taste sensitivity
taste perversion
Task №6. Disturbance of smell. Fill the table
Name of the violation
hyposmia
hyposmia
hyperosmia
Anosmia
paraosmia
sensitization sensing
odor susceptibility
odor perception
Description
Description
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PART 2. Solve cases and answer the questions
Case 1. Galina Ivanovna is 30 years old. The functions of
the hearing organs are normal. Sound signals were
continuously turned on: the first with a frequency of
35,000 Hz, the second - 9 Hz, the third - 12,000 Hz.
Which of the signal will Galina Ivanovna hear?Why?
Answer:
A 12,000 Hz sound wave will be audible to
Galina Ivanovna. She won't be able to hear
noises between 35000 and 9 Hz since
humans only detect sounds between 16 and
20,000 Hz.
Case 2. Two friends went to the lake for swimming.
Answer: Someone on the coast will hear it.
Suddenly there was a strong sound, just like a gun shot.
Since the sound often travels to one ear
At that time, one of the friends was under water, the
before the other, a person may readily detect
second on the boat. They tried to determine the direction the direction of the sound source. The brain
of its source.
detects this minute difference in time and
Who can more easily determine the direction of the sound minute variation in sound intensity and uses
source? Why?
these to estimate the direction of the sound
source.
Air is less dense than water. Sound travels
more rapidly in a more crowded space. As a
result, there will be less of a delay between
the arrival of sound in the left and right ears
than in the air. Inferring the direction of
sound is thus simpler in the air than in water.
Case 3. It is known that conduction of sound occurs by
Answer:
air conduction and bone conduction.
Air conduction and bone conduction both
In case of damage of air conduction, can bone conduction have a role in how sounds are perceived. For
be maintained? What does this indicate?
instance, when there is hearing loss, the
auditory ossicles' natural movement is
compromised, which affects air conduction.
Bone conduction might, however, continue.
You need to place a sounding item on a
section of the head to confirm this
(preferably on the mastoid process).
Case 4. В The examination revealed that the patient had Answer:
damaged the semicircular canals of the inner ear.
Yes, it is possible since the inner ear's
Can he detect the linear acceleration of his body in
semicircular channel receptors pick up on
space?
changes in the body's movement speed.
Receptors found in the vestibule sacs sense
how the head is positioned in space.
Case 5. Seasickness is a feeling of nausea and dizziness
Answer:
due to monotonous fluctuations.
The pathological condition of seasickness is
In which case does a person endure the symptoms of
brought on by rolling of the sea. It shows
Seasickness — on the ship’s deck or in the cabin? Explain symptoms
like
nauseousness,
the reason for this phenomenon.
lightheadedness,
cephalgia,
vomiting,
malaise,
emotional
deviations
(apathy/excitement),
dropping
blood
pressure, and arrhythmia.
Reasons: intense nature of the pitching,
alcohol intake, fatty foods, overeating,
chronic diseases, etc.
Case 6. The man complained that sometimes he has
Answer:
decreased taste sense of the food he is having.
The components of the taste sensation
He also noticed that this occurs if he has a great
system are as follows: 1) the flavor substance
excitement.
in the mouth; 2) the substance's dissolution
by saliva; 3) the penetration of dissolved
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Is his decreased taste sense associated with his great
excitement? Explain your answer.
particles of the substance to the taste
receptors; 4) irritation of the taste receptors;
and 5) the perception of taste. When
contrasting a person's calm demeanor with a
condition of intense emotional arousal, it is
important to focus on the second factor,
which is the saliva's role in the substance's
disintegration. Salivation is known to be
hindered by intense emotional arousal due to
norepinephrine's action (a mediator of the
postganglionic link of the sympathetic
division of the autonomic nervous system).
Because of this, in the dry oral cavity, the
taste sensations will be noticeably weakened.
Case 7. The patient was diagnosed with bilateral lesion of Answer: loss of taste and dysfunction of
the lingual nerve.
salivary gland.
What kind of failure occurs in such a condition, and why? The anterior two-thirds of the tongue supply
sensory innervation to the lingual nerve. It
has fibers from both the face nerve and the
mandibular division of the trigeminal nerve
(CN V3) (CN VII). Trigeminal nerve fibers
are responsible for touch, pain, and warmth
(general feeling), whereas face nerve fibers
are responsible for taste (special sensation).
Case 8. The person who entered the room felt the sharp
Answer:
smell of flowers. After a while he stopped feeling the
A person becomes addicted to the scent of an
smell.
odorous chemical after repeatedly irritating
Why do people who have been in this room for a long
their smell receptors, and they stop sensing
time stop feeling the smell?
it. Contrast, mutual weakening of scents in a
combination of odorous substances, and
combining the odors of many substances into
one that has a qualitatively different smell are
all conceivable effects of odors.
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