Senses
Motor system
Senses - motor system2
Olfactory and gustatory system
Senses - motor system3
Senses - motor system4
Olfaction and sense of taste are closely interconnected „chemical senses“
Senses - motor system5
Olfaction and sense of taste are closely interconnected „chemical senses“
Olfaction
Senses - motor system6
• Ability to sense chemical compounds dispersed in the air
• Influenced evolution of neocortex
• Place identification
• Food identification
• Humans are microolfactoric organisms
– Loss of analytic capabilities led to a relative enhancement
of psychological component
Olfaction
Senses - motor system7
• Ability to sense chemical compounds dispersed in the air
• Influenced evolution of neocortex
• Place identification
• Food identification
• Humans are microolfactoric organisms
– Loss of analytic capabilities led to a relative enhancement
of psychological component
Olfaction
Senses - motor system8
• Ability to sense chemical compounds dispersed in the air
• Influenced evolution of neocortex
• Place identification
• Food identification
• Humans are microolfactoric organisms
– Loss of analytic capabilities led to a relative enhancement
of psychological component
Olfaction
Senses - motor system9
• Humans can distinguish about 80 chemicals
and 144-10000 odors
• Better sensitivity to liposoluble molecules
• Olfaction degenerates with age
http://www.slideshare.net/drpsdeb/presentations
http://www.slideshare.net/drpsdeb/presentations
✓ fragnant
✓ woody/resinous
✓ fruit (other than citrus)
✓ putrid
✓ chemical
✓ minty/peppermint
✓ sweet
✓ popcorn
✓ burning
✓ lemon
Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization.
Castro JB, Ramanathan A, Chennubhotla CS.
PLoS One. 2013 Sep 18;8(9):e73289. doi: 10.1371/journal.pone.0073289. eCollection 2013.
PMID:24058466
10 basic categories of odors
Senses - motor system10
Senses - motor system11
Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization.
Castro JB, Ramanathan A, Chennubhotla CS.
PLoS One. 2013 Sep 18;8(9):e73289. doi: 10.1371/journal.pone.0073289. eCollection 2013.
PMID:24058466
Olfaction
Senses - motor system12
http://www.slideshare.net/drpsdeb/presentations
Olfaction
Senses - motor system13
http://www.slideshare.net/drpsdeb/presentations
Olfaction
Senses - motor system14
http://www.slideshare.net/drpsdeb/presentations
Sense of taste
Senses - motor system15
• Ability to sense chemical compounds dissolved in saliva
• Close connection with olfaction
• Food identification
• Connection to the reward system
Sense of taste
Senses - motor system16
• Ability to sense chemical compounds dissolved in saliva
• Close connection with olfaction
• Food identification
• Connection to the reward system
Gustatory system
Senses - motor system17 http://www.slideshare.net/drpsdeb/presentations
Gustatory system
Senses - motor system18
http://media.tumblr.com/1abd820225a3792d0787cd3b53ada989/tumblr_inline_mqyyza95I71qz4rgp.png
http://www.slideshare.net/drpsdeb/presentations
Auditory and vestibular system
Senses - motor system19
Auditory system
Senses - motor system20
• Transduction of sound waves to the receptor
and the action potential
• Transmission to CNS
• Signal processing
– Sound decoding
– Interpretation
http://www.slideshare.net/drpsdeb/presentations
Auditory system
Senses - motor system21
• Produced by vibration of solid object in the
air or water
• Sound characteristics
– Frequency – pitch
– Amplitude – intensity
– Timbre – given by representation of harmonic
frequencies of the oscillation
• Pure tone
• Complex sound http://www.slideshare.net/drpsdeb/presentations
Sound
Senses - motor system22
• Pure tone
– Determined by frequency
• Complex sound
– Sum of pure tones
➢ Harmonic (musical)
• periodic
➢ Disharmonic (noise)
• aperiodic
http://www.earmaster.com/music-theory-
online/ch03/chapter-3-2.html
http://www.acoustics.salford.ac.uk/acoustics_info/sound_synthesis/
http://www.slideshare.net/drpsdeb/presentations
Audible spectrum
Senses - motor system23
http://www.slideshare.net/drpsdeb/presentations
The intensity and volume of sound
Senses - motor system24
• Intensity of sound
– Amplitude
➢ Whisper – 20 dB
➢ Speaking - 65 dB
➢ Jet engine – 100 dB
➢ Pain treshold – 120 dB
• Volume
– Subjectively perceived intensity
External ear
Senses - motor system25
✓ Transmission of acoustic signal from environment to the tympanic membrane
http://www.slideshare.net/drpsdeb/presentations
Middle ear
Senses - motor system26
✓ Transmission of acoustic signal from the tympanic membrane to the oval window
and perilymph/basilar membrane
http://www.slideshare.net/drpsdeb/presentations
Middle ear
Senses - motor system27
• A significant difference in acoustic impedance
between air and perilymph
• Signal amplification
– Tympanic membrane area/oval window area
– Ossicles
• Protective function
– m.stapedius and tensor tympani
– Eustachian tube
http://slideplayer.com/slide/3433153/
Inner ear
Senses - motor system28
✓ Transduction of perilymph/basilar membrane vibrations to receptor and action potential
http://www.slideshare.net/drpsdeb/presentations
Tonotopic arrangement
Senses - motor system29
• Proximal part
– high frequency
• Distal part
– low frequency
http://www.slideshare.net/drpsdeb/presentations
Basilar membrane
Senses - motor system30
• Basal part
– Narrow and tight
High frquencies
• Apical part
– Wide and loose
Low frequencies
http://lh6.ggpht.com/_RIjx_Mg4ZVM/TNeYbcwJOYI/AAAAAAAACmA/9S_7HaZu5DI/s1600-h/image%5B62%5D.png
https://www.semanticscholar.org/paper/Mass-and-Stiffness-Impact-on-the-Middle-Ear-and-the-Kim-
Koo/16a2a6b5ffd1c963efd906cea109277bfbf0d7e3/figure/3
Organ of Corti
Senses - motor system31
➢Inner hair cells
➢ aprox. 3 500
➢Outer hair cells
➢ aprox. 12 000
➢Tectorial membrane
http://www.slideshare.net/drpsdeb/presentations
Inner hair cells
Senses - motor system32
➢ Sensory function
http://www.slideshare.net/drpsdeb/presentations
Outer hair cells
Senses - motor system33
• Modulation of the signal
✓ Amplification of required frequencies
• The number increases towards apex
(low frequencies)
http://www.slideshare.net/drpsdeb/presentations
http://www.neurophys.wisc.edu/auditory/johc.html
Sound processing
Senses - motor system34
• Nucleus spiralis cochleae
• Nucleus cochlearis ventralis
– Information about intensity
– Time delay – the sound direction
• Nucleus cochlearis dorsalis
– Information about frequency
• Olivary nuclei
– Analysis of direction
– Modulation (increase) of the outer hair cells sensitivity
• Colliculi inferiores
– Integration of information from the lower structures
– Centre of acoustic reflexes
• N. corporis geniculati medialis
– Thalamus
• Auditory cortex
http://www.slideshare.net/drpsdeb/presentations
Auditory cortex
Senses - motor system35
http://www.slideshare.net/drpsdeb/presentations
Vestibular system
Senses - motor system36
• Associated with auditory system
– Anatomic localization
– Hair cells
• Information about
➢ Position
➢ Acceleration
✓Linear
✓Angular
http://www.slideshare.net/CsillaEgri/presentations
Information about position
and linear acceleration
Senses - motor system37
• Macula
– CaCO3 crystals
• Utriculus
– Horizontal macula
• Sacculus
– Vertical macula
http://www.slideshare.net/CsillaEgri/presentations
Mechanism of reception
➢Flexion towards stereocilia
̶ Mechanically activated K+ channels are opened –depolarization
➢Flexion away from stereocilia
̶ The channels are clsed - hyperpolariztion
http://www.slideshare.net/CsillaEgri/presentations
Senses - motor system38
Information about angular
acceleration
Senses - motor system39
• Ampulla
• Semicircular canals
– Upper
– Horizontal
– Posterior
http://www.slideshare.net/CsillaEgri/presentations
Vestibular nuclei
Senses - motor system40
✓ Integration of vestibular,
visual and
somatosensoric
information
✓ Projections
• Cerebellum
• Oculomotoric nuclei
• Nucleus of n. Accessorius –
the muscles of the neck
• Spinal nuclei
• Thalamus - cortex
http://www.slideshare.net/CsillaEgri/presentations
Vision
Senses - motor system41
Light
Senses - motor system42
✓ Electromagnetic radiation with wavelengths in range of 400 – 700 nm
https://upload.wikimedia.org/wikipedia/commons/f/f1/EM_spectrum.svg
Color mixing
Senses - motor system43 http://www.indiana.edu/~jkmedia/classes/images/colormodes.jpg
Photoreceptive organ
Senses - motor system44
✓Light detection
✓Image formation
Light detection
Senses - motor system45
• Circadian activity
– Both prokaryotes and eukaryotes
– Day/night cycle is the most influential and
the most stable biorhythm
– Oscillation with a period of aprox. 24 hours
even without signals from environment
– Environmental signals synchronize circadian
activity
• Seasonal activity https://www.pointsdevue.com/article/good-blue-and-chronobiology-light-and-non-visual-functions
Light detection
Senses - motor system46
• Circadian activity
– Both prokaryotes and eukaryotes
– Day/night cycle is the most influential and
the most stable biorhythm
– Oscillation with a period of aprox. 24 hours
even without signals from environment
– Environmental signals synchronize circadian
activity
• Seasonal activity https://www.pointsdevue.com/article/good-blue-and-chronobiology-light-and-non-visual-functions
Circadian activity
Senses - motor system47
https://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Biological_clock_human.svg/2000px-Biological_clock_human.svg.png
Biological clock
Senses - motor system48
• Cellular level
– Group of proteins rhythmically expressed creating
interconnected feedback loops (about 24hours)
• Peripheral Clock protein expression
• Tissue level
– Peripheral oscillators
– Adrenal gland, lung, liver, pancreas, skin
– Influenced by neurohumoral factors and also by light
• Central pacemaker
– Hypothalamus (nucleus suprachiasmaticus)
• Central clock protein expression
• Information about illumination from retina (specialized ganglion
cells) – synchronization of central pacemaker
➢ Pineal gland - melatonin
➢ Autonomnic nervous system – adreanl gland - cortisol
http://slideplayer.com/slide/7013288/
Central pacemaker synchronization
Senses - motor system49
Wahl S, Engelhardt M, Schaupp P, Lappe C, Ivanov IV. The inner clock-Blue
light sets the human rhythm. J Biophotonics. 2019; e201900102.
(1% of ganglion cells)
Image formation
Senses - motor system50
➢ Shape
➢ Color
➢ Localization
➢ Movement
➢ Image interpretation - CNS
http://www.slideshare.net/CsillaEgri/presentations
Image formation
Senses - motor system51
http://www.slideshare.net/drpsdeb/presentations
Senses - motor system52
http://www.slideshare.net/drpsdeb/presentations
Photopigment of rods
Senses - motor system53
Rhodopsin
• Opsin
– G – protein
• Retinal
– Retinol aldehyde (vit. A)
http://www.slideshare.net/CsillaEgri/presentations
Photopigments of cones
Senses - motor system
54
• 3 types of cones - 3 types of
photopigment
– Blue(420nm)
– Green (530nm)
– Red (560nm)
• Color is interpreted by
ratio of cone stimulation
– Orange (580nm)
• Blue: 0%
• Green: 42%
• Red:99%
Rod
http://www.slideshare.net/CsillaEgri/presentations
Phototransduction
Senses - motor system
55
• Photoreceptors continuously release
neurotransmitter (glutamate) in darkness
• In response to the light, the membrane
hyperpolarizes and release less
neurotransmitter
http://www.slideshare.net/drpsdeb/presentations
Adaptation to the light/darkness
Senses - motor system
56
• Optic adaptation
– Constriction of pupils
• Photoreceptor adaptation
– Ca2+ inhibits guanylate cyclase
– cGMP gated Na+ channels...
– Darkness
• Higher Ca2+ levels → cGMP decreased → membrane
more hyperpolarized → „higher sensitivity to light“
– Light
• Lower Ca2+ levels → cGMP increased → membrane
more depolraized → „lower senzitivity to light“
http://www.slidesare.net/drpsdeb/presentations
Retina
Senses - motor system57
• Photoreceptors
• Interneurons
– Horizontal cells
• Horizontal interconnection
– Bipolar cells
• Vertical interconnection
– Amacrine cells
• Both horizontal and vertical interconnection
• Ganglion cells
– AP generation
– Transmission of AP to the brain
http://www.slideshare.net/CsillaEgri/presentations
Retina
Senses - motor system58
• Fovea
– Low convergence
• Small receptive field
• High resolution
– Lower sensitivity to light
• Periphery of retina
– High degree of convergence
• Large receptive field
• Low resolution
– High sensitivity to light
http://www.slideshare.net/CsillaEgri/presentations
Receptive field
Senses - motor system59 http://www.slideshare.net/drpsdeb/presentations
Receptive field
Senses - motor system60 http://www.slideshare.net/drpsdeb/presentations
Receptive field
Senses - motor system61 http://www.slideshare.net/drpsdeb/presentations
Receptive field
Senses - motor system62 http://www.slideshare.net/drpsdeb/presentations
Receptive field
Senses - motor system63
• Magnocellular system
– Large receptive field
– Rods and cones
– M ganglion cells (10%)
– High speed of velocity
– Brightness/low contrast sensitivity
– Minimal sensitivity to color
• Parvocellular system
– Small receptive field
– Cones and rods
– P ganglion cells (80%)
– Low speed of velocity
– Low sensitivity in low contrast
– Good sensitivity to color
http://www.slideshare.net/drpsdeb/presentations
Receptive field
Senses - motor system64
• Magnocellular system
– Large receptive field
– Rods and cones
– M ganglion cells (10%)
– High speed of velocity
– Brightness/low contrast sensitivity
– Minimal sensitivity to color
• Parvocellular system
– Small receptive field
– Cones and rods
– P ganglion cells (80%)
– Low speed of velocity
– Low sensitivity in low contrast
– Good sensitivity to color
http://www.slideshare.net/drpsdeb/presentations
Receptive field
Senses - motor system65
• Magnocellular system
– Large receptive field
– Rods and cones
– M ganglion cells (10%)
– High speed of velocity
– Brightness/low contrast sensitivity
– Minimal sensitivity to color
• Parvocellular system
– Small receptive field
– Cones and rods
– P ganglion cells (80%)
– Low speed of velocity
– Low sensitivity in low contrast
– Good sensitivity to color
http://www.slideshare.net/drpsdeb/presentations
Optic nerve and optic tract
Senses - motor system66
• Optic nerve
– Signal from one eye
– Signal from „whole“ visual field
• Optic tract
– Signal from both eyes
– Signal from half of visual field
http://www.slideshare.net/CsillaEgri/presentations
https://www.aafp.org/afp/2013/0901/p319.pdf
Visual pathways
Senses - motor system67
• Nucleus corporis geniculati lateralis
– Thalamus
– Majority of projections
– Via optic radiation to neocortex
• Hypothalamus
– Regulation circadian activity
• Pretectum
– Pupillary reflex
• Colliculi superiores
– Reflex movement of eyes and head
http://www.slideshare.net/drpsdeb/presentations
Primary visual cortex
Senses - motor system68
Retinotopic organization
http://www.slideshare.net/CsillaEgri/presentations
http://www.slideshare.net/drpsdeb/presentations
Nystagmus
Senses - motor system69
• Involuntary rhythmic eye movement
• Physiological
– Postrotatinal
– Optokinetic
• Pathologic
✓ Peripheral
• Vestibular system pathologies
✓ Central
• CNS damage (cerebellum, midbrain…)
http://dxline.info/img/new_ail/nystagmus.jpg
Saccadic eye movements
https://en.wikipedia.org/wiki/Saccade#/media/File:Szakkad.jpg
Senses - motor system70
Saccadic eye movements
https://s-media-cache-ak0.pinimg.com/564x/51/f7/26/51f7267e7c8a59caa90f904cd4f965eb.jpg
https://en.wikipedia.org/wiki/Saccade#/media/File:Szakkad.jpg
Reflexive
exploration
Intentional
exploration
Assistance in controlling
saccades during
movement
Senses - motor system71
Senses - motor system72
https://nasregion.cz/praha/praha-5-i-letos-podpori-filmovy-festival-febiofest
Pupillary reflex
http://www.ubooks.pub/Books/B0/E27R7642/MAIN/images/1509_Pupillary_Reflex_Pathways.jpg
73
Senses - motor system
Motor system
Senses - motor system74
Introduction
Senses - motor system75
• Skeletal muscle contraction is initiated by
lower motor neuron
• Lower motor neuron is a part of local
reflex circuits
• The information from several sources is
integrated in the lower motor neuron
– Higher levels of CNS
➢Upper motor neuron, tectum, n.
ruber, brain stem
– Proprioception
http://www.frontiersin.org/files/Articles/42416/fnhum-07-00085-HTML/image_m/fnhum-07-00085-g001.jpg
Introduction
Senses - motor system76
• Skeletal muscle contraction is initiated by
lower motor neuron
• Lower motor neuron is a part of local
reflex circuits
• The information from several sources is
integrated in the lower motor neuron
– Higher levels of CNS
➢Upper motor neuron, tectum, n.
ruber, brain stem
– Proprioception
http://www.frontiersin.org/files/Articles/42416/fnhum-07-00085-HTML/image_m/fnhum-07-00085-g001.jpg
Introduction
Senses - motor system77
• Skeletal muscle contraction is initiated by
lower motor neuron
• Lower motor neuron is a part of local
reflex circuits
• The information from several sources is
integrated in the lower motor neuron
– Higher levels of CNS
➢Upper motor neuron, tectum, n.
ruber, brain stem
– Proprioception
http://www.frontiersin.org/files/Articles/42416/fnhum-07-00085-HTML/image_m/fnhum-07-00085-g001.jpg
Lower motor neuron
Senses - motor system78
http://epomedicine.com/wp-content/uploads/2016/07/gamma-loop.jpg
• α motoneuron
– Innervation of contractile
elements
– Extrafusal fibers
– Muscle contraction
• γ motoneuron
– Innervation of muscle
spindles
– Intrafusal fibers
– Alignment of muscle
spindles
– Gamma loop
• β motoneuron
– Both extrafusal and intrafusal fiberrs
Lower motor neuron
Senses - motor system79
Topography
http://www.slideshare.net/drpsdeb/presentations
Motor unit
Senses - motor system80
• A typical muscle is innervated by about 100
motoneurons which are localized in motor
nucleus
• Each motoneuron innervate from 100 to 1000
muscle fibers and one muscle fiber is innervated
by a single motoneuron
• The ensemble of muscle fibers innervated by a
single neuron and corresponding motoneuron
constitutes the motor unit
http://www.slideshare.net/drpsdeb/presentations
Motor unit
Senses - motor system81
• A typical muscle is innervated by about 100
motoneurons which are localized in motor
nucleus
• Each motoneuron innervate from 100 to 1000
muscle fibers and one muscle fiber is innervated
by a single motoneuron
• The ensemble of muscle fibers innervated by a
single neuron and corresponding motoneuron
constitutes the motor unit
http://www.slideshare.net/drpsdeb/presentations
Types of muscle fibers
Senses - motor system82
http://www.slideshare.net/drpsdeb/presentations
Fast fibers
➢ Performance
➢ Fast fatigue-resistant – normal performance
➢ Fast fatigable – high performance
Slow fibers
➢ Endurance
➢ Fatigue resistant
Types of muscle fibers
Senses - motor system83
http://www.slideshare.net/drpsdeb/presentations
Fast fibers
➢ Performance
➢ Fast fatigue-resistant – normal performance
➢ Fast fatigable – high performance
Slow fibers
➢ Endurance
➢ Fatigue resistant
The recruitment of motor neurons
Senses - motor system84
http://www.slideshare.net/drpsdeb/presentations
m. gastrocnemius in a cat
Neuromuscular junction
Senses - motor system85
http://classes.midlandstech.edu/carterp/Courses/bio210/chap09/210_figure_09_11_labeled.jpg
Neuromuscular junction
Senses - motor system86
https://s3.amazonaws.com/classconnection/803/flashcards/9818803/png/initiation-151586429D6310D1C56.png
Muscle fibers
Senses - motor system87
http://www.sivabio.50webs.com/mus019.jpg
Types of muscle contraction
Senses - motor system88 http://www.slideshare.net/drpsdeb/presentations
• Isotonic contraction
➢ Constant tension
➢ Concentric x excentric
contraction
• Isometric contraction
➢ Constant length
https://i0.wp.com/colebradburn.com/wp-content/uploads/2013/02/contractions.jpg
Proprioception
Senses - motor system89
• Information about the position of body parts in
relation to each other
(The sum of information about lengths of particular muscles)
• Information about movement
(The force and speed of muscle contraction)
• Reflex regulation of muscle activity
• Muscle spindles
– Lie in parallel with extrafusal muscle fibers
• Golgi tendon organ
– Arranged in series with extrafusal muscles http://www.slideshare.net/CsillaEgri/presentations
Reaction of muscle spindles and the Golgi tendon
organs to muscle fiber stretch/contraction
Senses - motor system90
http://www.slideshare.net/drpsdeb/presentations
http://www.slideshare.net/drpsdeb/presentations
Stretch (passive)
Muscle spindles reaction
Contraction (active)
Golgi tendon organ reaction
Hierarchic organization of motor system
Senses - motor system91
http://www.slideshare.net/drpsdeb/presentations
Hierarchic organization of motor system
Senses - motor system92
http://www.slideshare.net/drpsdeb/presentations
Reflex
Senses - motor system93
• Reflex movement
– Stereotype (predictable)
– Involuntary
• Proprioceptive
• Exteroceptive
• Monosynaptic
• Polysynaptic
• Monosegmental
• Polysegmental
http://www.slideshare.net/CsillaEgri/presentations
Proprioceptive reflexes
Senses - motor system94
• Myotatic reflex
– Monosynaptic
– Monosegmental
– Muscle spindle
➢ Homonymous muscle - activation
➢ Antagonist muscle - inhibition
✓ Phasic response (Ia)
– Protection against overstretch of extrafusal
fibrers
✓ Tonic response (Ia a II)
– Maintains muscle tone
http://www.slideshare.net/CsillaEgri/presentations
Senses - motor system95
http://www.slideshare.net/drpsdeb/presentations
Senses - motor system96
http://www.slideshare.net/drpsdeb/presentations
Proprioceptive reflexes
Senses - motor system97
• Inverse myotatic reflex
– Monosegmental
– Disynaptic/polysynaptic
– Golgi tendon organ
➢ Homonymous muscle – inhibition
➢ Antagonist muscle– activation
✓ Protection against muscle damage
caused by extensive force
http://www.slideshare.net/CsillaEgri/presentations
Senses - motor system98
http://www.slideshare.net/drpsdeb/presentations
Exteroceptive reflexes
Senses - motor system99
• Polysynaptic
• Polysegmental
http://images.slideplayer.com/15/4638059/slides/slide_37.jpg
Exteroceptive reflexes
Senses - motor system100
• Polysynaptic
• Polysegmental
http://www.easynotecards.com/uploads/920/77/1c7a7974_150bb922c9b__8000_00004383.png
Hierarchic organization of motor system
Senses - motor system101
http://www.slideshare.net/drpsdeb/presentations
Fixed action pattern and rhythmic movement
Senses - motor system102
• Fixed action pattern (e.g. Swallowing)
– Neuronal networks for complex motor activity
• Central pattern generator (e.g. Walking, breathing)
– Neuronal networks generating rhythmic activity
– „Spontaneously repeated fixed action patterns“
– No need of feedback
• Localization
– Walking – brain stem, lower thoracic and upper lumbar spinal cord
– Breathing – brain stem
– Swallowing - medulla oblongata/brain stem
• Variously expressed voluntary control
– Walking (full control)
– Breathing (partial control)
– Swallowing (limited control) http://www.slideshare.net/drpsdeb/presentations
Fixed action pattern and rhythmic movement
Senses - motor system103
Fig. 1. Neural control of locomotion. A) Increments in
the intensity of stimulation of the MLR in the high
decerebrate cat increased the cadence (step cycles/sec)
of locomotion. Adapted from Shik et al. 1966.[22] B)
Schematic of the velocity command hypothesis: a
command signal specifying increasing body velocity
descends from deep brain nuclei via the MLR to the
spinal cord and drives the timing element of the spinal
locomotor CPG to generate cycles of increasing cadence.
Extensor phase durations change more than flexor
phase durations. The command signal also drives the
pattern formation layer to generate cyclical activation of
flexor and extensor motoneurons. Loading of the
activated muscles (e.g. supporting the moving body
mass) is resisted by the muscles' intrinsic spring-like
properties. This is equivalent to displacement feedback.
Force and displacement sensed bymuscle
spindle and Golgi tendon organ afferents reflexly
activate motoneurons. A key role of these afferents is to
adjust the timing of phase transitions, presumably by
influencing or overriding the CPG timer. Adapted from
Prochazka & Ellaway 2012.[23]
https://en.wikipedia.org/wiki/Central_pattern_generator
Fixed action pattern and rhythmic movement
Senses - motor system104
Whelan PJ. Shining light into the black box of spinal
locomotor networks. Philosophical Transactions of the
Royal Society of London B: Biological Sciences.
2010;365:2383–2395.
Voluntary motor activity
Senses - motor system105
Idea
Association
cortex
Premotor +
Motor cortex
Basal
Ganglia
Lateral
cerebellum
Movement
Intermediate
Cerebellum
ExecutionPlanning
http://www.slideshare.net/drpsdeb/presentations
Voluntary motor activity
Senses - motor system106
• Result of cooperation of upper
and lower motor neuron
• Basal ganglia
– Motor gating – initiation of wanted
and inhibition of unwanted
movements
• Cerebellum
– Movement coordination
http://www.slideshare.net/drpsdeb/presentations
Pyramidal tract
Senses - motor system107
• Upper motor neuron
– Primary motor cortex
• Lower motor neuron
– Anterior horn of spinal cord
• Tractus corticospinalis lateralis
– 90% of fibers
• Tractus corticospinalis anterior
– 10% of fibers
– Cervical and upper thoracic segments
• Tractus corticobulbaris
http://images.slideplayer.com/14/4330915/slides/slide_34.jpg
Primary motor cortex
Senses - motor system108
http://www.emunix.emich.edu
Motor cortex
Senses - motor system109
• Primary motor cortex (area 4)
– Somatotopic organization
– Control of lower motor neuron
• Premotor cortex (area 6 laterally)
– Preparation of strategy of movement
• Sensor motor transformation
• Movement patterns selection
• Supplementary motor cortex
(area 6 medially)
– Involved in planning of complex movements
• Movement of both limbs
• Complex motion sequences
– Activated also by complex movement
rehearsal
http://www.slideshare.net/CsillaEgri/presentations
Basal ganglia
Senses - motor system110
• Corpus striatum
– Nucleus caudatus
– Putamen
• Globus pallidus
(Pallidum)
– Externum
– Internum
• Nucleus subthalamicus
• Substantia nigra
– Pars compacta
– Pars reticulata
• Thalamic motor nuclei
http://www.slideshare.net/CsillaEgri/presentations
Direct and indirect pathway differences
Senses - motor system111
http://www.slideshare.net/drpsdeb/presentations
• Direct pathway
➢ Motor cortex
activation
• Indirect pathway
➢ Motor cortex
inhibition
Dopaminergic projections
Senses - motor system112
http://www.slideshare.net/drpsdeb/presentations
• Dopaminergic
projections are crucial
for the function of
corpus striatum
• S. nigra pars compacta
• Direct pathway
activation
➢ D1 receptors
• Indirect pathway
inhibition
➢ D2 receptors
Basal ganglia
Senses - motor system113
• Beside motor loop there are other loops
associated with other thalamic nuclei
• „Gating“ of the other sort of information
• Association loop
• Limbic loop
• Basal ganglia play an important role in
information processing in general and this is
crucial for thinking process
• Connections of corpus striatum are plastic what
allows learning and this was very important
during evolution
http://www.slideshare.net/CsillaEgri/presentations
Cerebellum
Senses - motor system114
• Coordination
• Cerebellum plays an important role
not only in the coordination of
movement, but also in the
"coordination" of thoughts
http://www.slideshare.net/HarshshaH103/cerebellum-its-function-and-releveance-in-psychiatry