The neural organization of posterior brainThe neural organization of posterior brain Nuclei of cranial nervesNuclei of cranial nerves::

sensorysensory : : VV, , VVІІ, ІІ, VVІІІ, ІХ, Х,ІІІ, ІХ, Х,

vestibular nucleivestibular nuclei: : Shvalbe, Bechterew, Deyters,Shvalbe, Bechterew, Deyters,

descending nucleusdescending nucleus

motormotor : : VV, , VVІ, І, VVІІ, ІХ, Х, ХІ, ХІІІІ, ІХ, Х, ХІ, ХІІ

vegetativevegetative :: VVІІ, ІХ, ХІІ, ІХ, Х The nuclei of ascending somatosensory The nuclei of ascending somatosensory

system system ::

nuclei Gaulle and Burdachnuclei Gaulle and Burdach Reticular formationReticular formation

Ways leading from the spinal cord to higher Ways leading from the spinal cord to higher situated parts of the CNSsituated parts of the CNS

SensorySensory ConductionConduction VegetativeVegetative ReflexReflex

Sensory function of posterior Sensory function of posterior brainbrain

1 .1 . Receptors of headReceptors of head::-- skin of face; skin of face;

-nasal mucosa;-nasal mucosa;

-oral mucosa;-oral mucosa;

-teeth;-teeth;

-taste receptors;-taste receptors;

-proprioceptors of the muscles -proprioceptors of the muscles ((facial, masticatory,facial, masticatory,

tongue, pharynx)tongue, pharynx)

-auditory receptors;-auditory receptors;

-receptors of vestibular apparatus;-receptors of vestibular apparatus;

2 .2 . Proprioceptors of neck, trunk, Proprioceptors of neck, trunk, limbslimbs

3 .3 . Receptors of internal organsReceptors of internal organs

Conduction functions of posterior Conduction functions of posterior brainbrain

Ascending pathways within Ascending pathways within ::

- lemnis system- lemnis system

- extralemnis system- extralemnis system

- anterolateralis system- anterolateralis system

Descending pathways to the spinal Descending pathways to the spinal cordcord

Vegetative function of Vegetative function of posterior brainposterior brain

Participation in the provision of external respiration (the respiratory centerParticipation in the provision of external respiration (the respiratory center))

Participation in the regulation of the Participation in the regulation of the circulatory system (cardiovascular circulatory system (cardiovascular center)center) Participation in the regulation of Participation in the regulation of digestion:digestion:

chewing center chewing center swallowing centerswallowing center center of salivationcenter of salivation center of parasympathetic regulation of secretion and center of parasympathetic regulation of secretion and

motilitymotility of stomach, pancreas, gall bladder,of stomach, pancreas, gall bladder, (food center)(food center)

Reflex functions of posterior Reflex functions of posterior brainbrain

Maintaining a posture of antigravityMaintaining a posture of antigravity

Centers that provide Centers that provide antigravity postureantigravity posture

- Vestibular nucleusVestibular nucleus

- reticular nucleireticular nuclei- bridge formationbridge formation

- Nuclei of reticular Nuclei of reticular formation of the medulla formation of the medulla oblongataoblongata

2. 2. Redistribution of body muscle tone Redistribution of body muscle tone by changing head positionby changing head position

Reflexes to ensure redistribution of muscle tone Reflexes to ensure redistribution of muscle tone (tonic posture reflexes):(tonic posture reflexes):

A) Vestibular staticA) Vestibular static

B) Cervical tonicB) Cervical tonic

Vestibular static reflexes Vestibular static reflexes Reflex arcReflex arcReceptorReceptor : : Vestibular Vestibular receptor (spherical and elliptical receptor (spherical and elliptical

sacs)sacs)

CenterCenter: : vestibular nucleus of medulla oblongatavestibular nucleus of medulla oblongata

Efferent link Efferent link : : vestibulospinal path fibers which ends vestibulospinal path fibers which ends on α-on α- motoneurons of spinal motoneurons of spinal cordcord

EffectorEffector:: extensor excited,extensor excited, flexors inhibitedflexors inhibited

Types of static vestibular reflexesTypes of static vestibular reflexes When lifting the head increases When lifting the head increases

extensor muscle tone of upper limbs extensor muscle tone of upper limbs and reduced muscle tone of extensor and reduced muscle tone of extensor of hind limbof hind limb

When retracting the head increases When retracting the head increases extensor muscle tone of hind limbs extensor muscle tone of hind limbs and reduced muscle tone of extensor and reduced muscle tone of extensor of upper limbsof upper limbs

When tilt head sideways increases When tilt head sideways increases extensor muscle tone on the side extensor muscle tone on the side where the head is tiltedwhere the head is tilted

Neck tonic reflexesNeck tonic reflexes Reflex arcReflex arcReceptorReceptor : : proprioceptors of neck musclesproprioceptors of neck muscles

CenterCenter : : motor nuclei of medulla oblongatamotor nuclei of medulla oblongata

Efferent linkEfferent link: : - - vestibulospinal path fibersvestibulospinal path fibers which ends on α-motoneuronswhich ends on α-motoneurons of spinal cord;of spinal cord; -- from the oculomotor nerve nuclei from the oculomotor nerve nuclei

(nuclei III, IV, VI of cranial nerves) (nuclei III, IV, VI of cranial nerves) to the muscles of the eyeto the muscles of the eye

EffectorEffector: : - Extensors excited,- Extensors excited, flexors inhibitedflexors inhibited - Movements of eyeballs- Movements of eyeballs

The neural organization of the midbrainThe neural organization of the midbrain

The red nucleusThe red nucleus

The black substanceThe black substance

Midbrain reticular formationMidbrain reticular formation

Nuclei of III, IV pairs of cranial nervesNuclei of III, IV pairs of cranial nerves

Corpora quadrigeminaCorpora quadrigemina

Descending and ascending pathwaysDescending and ascending pathways

SensorySensory

ConductionConduction

VegetativeVegetative

ReflexReflex

Sensory functions of midbrainSensory functions of midbrain

Anterior hillocks of corpora quadrigeminaAnterior hillocks of corpora quadrigemina areare primary visual centersprimary visual centers

Posterior hillocks of corpora quadrigemina Posterior hillocks of corpora quadrigemina are primary auditory centersare primary auditory centers

Vegetative functions of the Vegetative functions of the midbrainmidbrain

Associated with the activity of parasympathetic Associated with the activity of parasympathetic nucleinuclei (ІІІ (ІІІ pairpair))

Fibres of these nerves innervateFibres of these nerves innervate - ciliary muscle - ciliary muscle - sphincter pupil- sphincter pupil

Through activation of these nerves isThrough activation of these nerves is - accommodation eyes- accommodation eyes - adaptation of the eye- adaptation of the eye

Decerebrate stiffnessDecerebrate stiffness

Reflexes straighteningReflexes straightening

Statokinetic reflexesStatokinetic reflexes

Approximate reflexesApproximate reflexes

Reflex functions of midbrainReflex functions of midbrain

Decerebrate stiffnessDecerebrate stiffnessCondition that occurs after crossing the Condition that occurs after crossing the midbrain and is characterized by a sharp midbrain and is characterized by a sharp increase in muscle tone - extensorincrease in muscle tone - extensor

Reflexes straighteningReflexes straightening

Reflexes, aimed at protecting the Reflexes, aimed at protecting the natural posture animals crown topnatural posture animals crown top

Reflex arcReflex arcreceptors of the vestibular analyzer receptors of the vestibular analyzer

(unnatural head position)(unnatural head position)

turn the head upside crownturn the head upside crown

proprioceptors of neck proprioceptors of neck musclesmuscles

redistribution of muscle tone of trunk redistribution of muscle tone of trunk and extremitiesand extremities

animal becomes a natural animal becomes a natural positionposition

Statokinetic reflexStatokinetic reflex

Reflexes to preserve posture and maintain a balance in Reflexes to preserve posture and maintain a balance in the event of acceleration (horizontal, vertical, angular)the event of acceleration (horizontal, vertical, angular)

Reflex arcReflex arcAngular accelerationAngular acceleration

Medulla oblongata Medulla oblongata ( ( nucleus ofnucleus of VVІІІ ІІІ pairpair))

Excitation of hair cell of semicircular canalsExcitation of hair cell of semicircular canals

Vestibular nucleiVestibular nuclei

MidbrainMidbrain((nn. . oculomotor nervesoculomotor nerves))

Motoneurons of neck Motoneurons of neck musclesmuscles

Turning eyesTurning eyesTurning a headTurning a head

NNііstagm of head stagm of head –– head movements by the action of angular head movements by the action of angular acceleration (first fast in the opposite direction of motion, then acceleration (first fast in the opposite direction of motion, then slowly in the direction of movement)slowly in the direction of movement)

Nistagm of eyes Nistagm of eyes –– eye movements under the influence of eye movements under the influence of angular acceleration (first fast in the opposite direction of angular acceleration (first fast in the opposite direction of motion, then slowly in the direction of movement)motion, then slowly in the direction of movement)

The value of nystagm The value of nystagm –– preservation of normal visual preservation of normal visual orientation while drivingorientation while driving

Functions of a red nucleusFunctions of a red nucleus Provides malcontent movementsProvides malcontent movements Regulates muscle toneRegulates muscle tone - increases muscle tone of flexors- increases muscle tone of flexors - reduces muscle tone of extensors- reduces muscle tone of extensors

Functions of a black substanceFunctions of a black substance Provides a smooth motionProvides a smooth motion Adjust the contraction of facial muscles-flexorAdjust the contraction of facial muscles-flexor Provides friendly gesturesProvides friendly gestures Correction of motor programs (due to connections with Correction of motor programs (due to connections with

basal ganglia)basal ganglia) Synthesis of the precursor of dopamineSynthesis of the precursor of dopamine

Indicative reflexesIndicative reflexes Patrol reflexes,Patrol reflexes, reflexes, "what?“reflexes, "what?“

Reflexes that provide Reflexes that provide fast turn the head, fast turn the head,

trunk, eyes in the trunk, eyes in the direction of light or direction of light or sound stimulussound stimulus

1)1) TypesTypes::Indicative visual reflex (front hillocks)Indicative visual reflex (front hillocks)

Auditory indicative reflex (rear hillocks)Auditory indicative reflex (rear hillocks)

2) Mean2) Mean::Orientation for new situationsOrientation for new situations

Prepare to defendPrepare to defend

Neuron organization of reticular Neuron organization of reticular formationformation

About 40 nuclei that are partAbout 40 nuclei that are part - medulla oblongata- medulla oblongata - bridge- bridge - midbrain- midbrain It has direct links withIt has direct links with - spinal cord- spinal cord - nonspecific thalamic nuclei- nonspecific thalamic nuclei - other departments of the central nervous - other departments of the central nervous

systemsystem Neurons have a strong background impulse Neurons have a strong background impulse

activity (5 - 10 Hz) due toactivity (5 - 10 Hz) due to - a large number of afferent signals- a large number of afferent signals - actions of humoral factors- actions of humoral factors

Functions of reticular formationFunctions of reticular formation SensorySensoryReceives afferent information fromReceives afferent information from

- Extralemniscal somatosensory system- Extralemniscal somatosensory system

- visceral receptors- visceral receptors

- proprioceptors- proprioceptors

- receptors in the visual analyzer- receptors in the visual analyzer

- receptors in the auditory analyzer- receptors in the auditory analyzer MotorMotorInfluences on the tone of skeletal muscles by spinal cord Influences on the tone of skeletal muscles by spinal cord

motoneuronsmotoneurons

- Medial reticulospinal way (Varoli’s bridge)- Medial reticulospinal way (Varoli’s bridge)

excitation of extensor motoneuronsexcitation of extensor motoneurons

inhibition of flexors motoneurons inhibition of flexors motoneurons

- Lateral reticulospinal way (medulla oblongata)- Lateral reticulospinal way (medulla oblongata)

excitation of flexors motoneuronsexcitation of flexors motoneurons

inhibition of extensor motoneuronsinhibition of extensor motoneurons IntegrativeIntegrativeActivates the neurons of the cerebral cortexActivates the neurons of the cerebral cortex

Adjust the cycle sleep-cheerfulnessAdjust the cycle sleep-cheerfulness

Functions of the cerebellumFunctions of the cerebellum Creation of motor programsCreation of motor programs Correction of motor programsCorrection of motor programs

Ensuring the initiation of movementsEnsuring the initiation of movements

Coordination of movementsCoordination of movements EquilibrationEquilibration

Adaptive-trophic functionAdaptive-trophic function

Regulation of muscle toneRegulation of muscle tone Regulation of muscle strengthRegulation of muscle strength

Symptoms that occur with lesions Symptoms that occur with lesions of the cerebellumof the cerebellum

Ataxia - a violation of motor coordinationAtaxia - a violation of motor coordination Asthenia – reducing of muscle strengthAsthenia – reducing of muscle strength Dystonia - a violation of muscle toneDystonia - a violation of muscle tone Dysmetria - violation of movement Dysmetria - violation of movement

amplitudeamplitude AstaziaAstazia - not the ability to perform precise - not the ability to perform precise movementsmovements Disequilibrium – violation of balanceDisequilibrium – violation of balance

Dysarthria - speech disordersDysarthria - speech disorders

Intentions tremor - shaking muscles Intentions tremor - shaking muscles when performing voluntary movementswhen performing voluntary movements

Eye nystagm, dizziness, vegetative Eye nystagm, dizziness, vegetative disturbancesdisturbances

Functions of ThalamusFunctions of Thalamus

The Thalamus is an important relay center

mainly for sensory fibers but also motor fibers from

the basal ganglia and cerebellum on their way to the

cerebral cortex. Crude appreciation of touch, pain

and temperature may occur here.

It also relays part of the reticular activationg system

which controls the level and state of consciousness.

Functional characteristic of thalamic nucleiFunctional characteristic of thalamic nuclei Specific core switch (relay)Specific core switch (relay)Receives information from sensory systems (somatosensory, visual, auditory) Receives information from sensory systems (somatosensory, visual, auditory)

and switch to the appropriate sensory cortex areaand switch to the appropriate sensory cortex area

Nonspecific nucleiNonspecific nucleiReceive information fromReceive information from- All sensesAll senses- Reticular formation of brainstemReticular formation of brainstem- HypothalamusHypothalamus

Turn information on sensory and motor cortex areas and limbic systemTurn information on sensory and motor cortex areas and limbic system

Associative nucleiAssociative nucleiReceives information from specific and nonspecific thalamic nucleiReceives information from specific and nonspecific thalamic nuclei

Turn information on associative cortex areaTurn information on associative cortex area

Relay nonsensory nucleiRelay nonsensory nucleiReceives information from the cerebellum, basal nucleiReceives information from the cerebellum, basal nuclei

Turn information on motor cortex areaTurn information on motor cortex area

Functions of hypothalamusFunctions of hypothalamus Contains higher centers of the sympathetic nervous systemContains higher centers of the sympathetic nervous system

Center of thermoregulationCenter of thermoregulation

Central regulation of water-salt metabolismCentral regulation of water-salt metabolism - central osmoreceptors- central osmoreceptors - thirst center- thirst center Food centerFood center - the hunger center- the hunger center - the center of saturation- the center of saturation Centers of sleep and wakeCenters of sleep and wake

Center of regulation of sexual behavior (pleasure Center of regulation of sexual behavior (pleasure center)center)

Participation in the formation of motivations and Participation in the formation of motivations and emotionsemotions

Neuroendocrine function (formation releasing Neuroendocrine function (formation releasing factor, vasopressin, oxytocin)factor, vasopressin, oxytocin)

Functions of basal nucleiFunctions of basal nuclei

Implementation of complex motor acts Implementation of complex motor acts that require education and trainingthat require education and training

(Cycle of shell)(Cycle of shell)

The formation and preservation of the The formation and preservation of the memory models of motor responses, memory models of motor responses, which are elements of behavior in which are elements of behavior in certain circumstancescertain circumstances

(Caudate nuclei cycle)(Caudate nuclei cycle)

Cycle of shellCycle of shell

Caudate nuclei cycleCaudate nuclei cycle