4. Reception, perception and transmission
of information
Reception, perception and transmission
of information
5. ANALYZER -
it`s specific sensory (receptory)
system of neurons that consist of:
• Peripheral part - receptors
• Conductive part – pathways and
afferent neurons
• Central part – cerebral cortex
7. GENERAL STRUCTURE
OF ANALYZERS
- NEURAL ENDINGS
- RECEPTOR CELLS
- PARTICULARIZED
SENSATION ORGANS
PERIFERAL PART
CONDUCTIVE PART
CENTRAL PART
- CONDUCTIVE WAYS
- CEREBRAL STRUCTURES
8. Main principles of the
analyzers composition
• Each analyser has a lot of neurons levels
that are related by the pathways
• Each level has a lot of neuronal fibers –
pathways
• Each level has a different amount of the
cells – they work according principles of
convergence and divergens
• Each level has a different function:
peripheral part – reception, middle part –
conduction, central part – analyse.
9. MAIN PROPERTIES
OF THE ANALYSERS:
• Detection of the stimuli by receptors
• Ability to form a receptor (generator)
potential
• Perception of the stimulies according to a
definite increasing force of the irritation.
• Transmission (spreading) of the stimulies.
• Conversion information into a special system
– code
• Adaptation to stimulies
• Cortical and subcortical information analyse
15. MAIN RECEPTOR
FUNCTIONS
• Perception of the irritation
• Excitation generating
• Primary analysis of excitation
• Coding information of irritation
parameters
16. MECHANISM OF RECEPTOR
EXCITATION
• Irritation impulse + receptor
→↑membrane permeability for Na→
depolarization (repolarization is in
photoreceptors!) and
- generator potential (GP) develops in
primary receptors
- receptor potential (RP) develops in
secondary receptors→ RP+RP+RP=GP →
GP+GP+GP=AP
18. Graphical representation of the sensory
nerve activity in case of stimuli applying of
different intensities and durations
19. General properties of local
potentials (LP)
- it doesn’t spread along the nerve
fibers
- it works according to law of
gradation
- it has ability to summation
- it hasn’t refractory period
- short-time duration of LP (but RP
has long-time duration)
20. PRIMARY ANALYSIS IS PROVIDED
for
- Different areas of receptive fields,
- Specific perception of irritation by
receptors
- Different levels of receptor excitations
- Different levels of receptors adaptation,
- Different time of excitation development
in receptors,
- Mechanisms of feed-back connection
between receptors and neural
21. Coding information
• - it`s a conversion information into a
specific system – code.
Transmission of impulses is effected by
a binary code. Presence of an impulse – is 1,
its absence equals to 0.
The information about the stimulies is
transmitted in the form of individual groups or
“volleys” of impulses.
The amplitude and duration of the
individual impulses passing identical along
the same fiber, but the frequency and number
of impulses in volley may be different.
22. 1. By change of number of AP:
If the sound has frequency less
then 1000 Hz, the cells form equal
amount of AP. If the sound has
frequency more then 1000 Hz, the
cells start to code impulses.
2. By change of impulses speed
transmission
Types of information
coding
23. The scheme of stimulus processing
and information coding
24. RECEPTORS ADAPTATION
it’s the increasing of irritation
threshold under the specific impulse
action, which acts a long period of time
Adaptation mechanisms:
- ↓amount of working receptors
- ↓ RP amplitude
- ↓ frequency of impulse conduction
- change of neural centres condition
25. The scheme of
adaptation of
slow- and fast-
adapting
receptors on
dependence with
their stimulation
27. COMPOSITION OF ANALYSERS
CONDUCTIVE PART
3 NEURONS:
- dendrites of 1-st sensor neurons
- axon of 1-st sensor neurons
- axon of 2-d sensor neurons (Т-neurons)
- axon of 3-d sensor neurons
Somato-sensor analyzer:
1-st neuron – spinal ganglies
2-nd neuron – cornu posterior of spinal
cord, Goll's and Burdach's nuclei
28. MAIN FUNCTIONS of ANALYZERS
CONDUCTIVE PART
- Excitation conduction
- Secondary analysis of
irritation
- Encoding irritation
information
29. LAWS OF IMPULSES
CONDUCTION in NERVES
- The law of anatomical and
physiological continuity of a
nerve
- The law of two-way
conduction
- The law of isolated
conduction along a nerve
32. Cortical information analysis
Motor areas involved with the
control of voluntary muscles
Motor speech
area (Broca`s
area)
Sensory areas involved with
cutaneous and other senses
Understanding speech, using
word
Parietal lobe
General interpretative area
34. Motor and sensory areas
trunk
neck
Upper arm
Lower arm
Hand, fingers,
and thumb
Upper face
Sensory areasMotor areas
35. FUNCTIONS OF
ANALYSERS CENTRAL
PART
- tertiary analisis of excitation
- transformation of excitation into
sensation
- formation of perceptible image
- memorization of perceptible image
36. PARAMETERS OF
ANALYSIS
• Intensity threshold (force) of irritation – it’s
min force of irritation, caused sensation
• Differential threshold of irritation – it’s min
force increment of irritation, caused sensation
• Spatial threshold of irritation – it’s min
distance between two irritation stimulus, that
permits these two stimulus to percept separately
The less receptive field the less spatial
threshold
• Temporal threshold – it’s min time between
two irritation stimulus, that permits these two
stimulus to percept separately
37. Perception of the stimulies according
a definite increasing proportion
• 1834 y. – Weber formulated the law that
states: S= a log R + b
Receptors in organism percept
difference force of the irritation if the
index between stimulies increases
according a definite proportion
100g – 3g
200g – 6g
600g – 18g
40. Mechanical sensationMechanical sensation
The pacinian corpuscle is a
very rapidly adapting receptor
with a large receptive field that is
used to encode high-frequency
(100–400 Hz) vibratory sensation.
The receptor is located on the end of a
group B myelinated fiber, which is inser-
ted into an onion-like lamellar capsule
The pacinian corpuscle is a
very rapidly adapting receptor
with a large receptive field that is
used to encode high-frequency
(100–400 Hz) vibratory sensation.
The receptor is located on the end of a
group B myelinated fiber, which is inser-
ted into an onion-like lamellar capsule
The spindle-shaped Ruffini's corpuscle
is a slowly adapting receptor that
encodes pressure. It has a large
receptive field that is used to encode
the magnitude of a stimulus.
The receptor is located on the terminal
of a group B axon that is covered by a
liquid-filled collagen capsule. Collagen
strands within the capsule make contact
with the nerve fiber and the overlying skin.
The spindle-shaped Ruffini's corpuscle
is a slowly adapting receptor that
encodes pressure. It has a large
receptive field that is used to encode
the magnitude of a stimulus.
The receptor is located on the terminal
of a group B axon that is covered by a
liquid-filled collagen capsule. Collagen
strands within the capsule make contact
with the nerve fiber and the overlying skin.
Meissner's corpuscle is a rapidly
adapting receptor that participates
in the touch sensation and low-
frequency (10–100 Hz) vibration.
The receptor is located at the end of a
single group B afferent fiber that is
inserted into a small capsule.
Meissner's corpuscle is a rapidly
adapting receptor that participates
in the touch sensation and low-
frequency (10–100 Hz) vibration.
The receptor is located at the end of a
single group B afferent fiber that is
inserted into a small capsule.
Merkel’s disk is a slowly adapting
receptor with a small receptive field
that is also used to encode the
touch sensation.
The epithelial sensory cells form synaptic
connections with branches of a
single group B afferent fiber.
Merkel’s disk is a slowly adapting
receptor with a small receptive field
that is also used to encode the
touch sensation.
The epithelial sensory cells form synaptic
connections with branches of a
single group B afferent fiber.
