functions of nervous system

Reflexes and methods of examination Reflexes and methods of examination Active movements Active movements Types of paralysis Types of paralysis

Syndromes of movement disturbances Syndromes of movement disturbances Syndromes of lesion of Cortical-Syndromes of lesion of Cortical-

Muscular Tract on different levelsMuscular Tract on different levels

Functions of nervous systemFunctions of nervous system

The main function of nervous systemThe main function of nervous system is is unification and regulation of unification and regulation of

different physiological processes. different physiological processes. That means that nervous system That means that nervous system

unites, integrates and unites, integrates and subordinates all the parts of subordinates all the parts of human body and provides its human body and provides its connection with environmentconnection with environment

Functions of nervous systemFunctions of nervous system

The base of nervous system activity is The base of nervous system activity is reflex principlereflex principle

Reflex – is a reaction of our organism to Reflex – is a reaction of our organism to various outside and inside effects. It is various outside and inside effects. It is provided by nervous systemprovided by nervous system

Reflex consists of:Reflex consists of:

afferent part (which accepts information)afferent part (which accepts information)

central part (that keeps information)central part (that keeps information)

efferent part (that creates response)efferent part (that creates response)

As a result we have a circle – like structure As a result we have a circle – like structure - receptor (primary information centre) – - receptor (primary information centre) – programme centre – executive apparatus programme centre – executive apparatus

Reflex archReflex arch

Reflexes are divided into:Reflexes are divided into:

simple and complexsimple and complex

inborn and trainedinborn and trained

conditioned and unconditioned conditioned and unconditioned

Unconditioned reflexes:Unconditioned reflexes:

They are inborn onesThey are inborn ones

They are phylogenetically old, that means they They are phylogenetically old, that means they were formed in course of phylogenesiswere formed in course of phylogenesis

They are based on certain anatomic structures They are based on certain anatomic structures (segments of spinal cord or brain stem)(segments of spinal cord or brain stem)

They exist even without brain cortex influenceThey exist even without brain cortex influence

They are inheritedThey are inherited

They can be regulated by brain cortexThey can be regulated by brain cortex

They are basis for the conditioned reflexesThey are basis for the conditioned reflexes

Conditioned reflexes:Conditioned reflexes:

They are the result of the individual experience They are the result of the individual experience and are formed during ontogenesisand are formed during ontogenesisThey are unstable, that means they need They are unstable, that means they need constant supportconstant supportThey aren’t based on certain anatomic They aren’t based on certain anatomic structuresstructuresThey are fixed in brain cortexThey are fixed in brain cortex

There are such conditioned reflexes as speaking, There are such conditioned reflexes as speaking, writing, reading, calculation, practicewriting, reading, calculation, practice

Unconditioned reflexes Unconditioned reflexes are divided into:are divided into:

Superficial and deepSuperficial and deep

Simple and complexSimple and complex

Unconditioned reflexes are divided Unconditioned reflexes are divided into:into:

Proprioceptive (stretch, periosteal, joint)Proprioceptive (stretch, periosteal, joint)

Exteroceptive (dermal, from mucose Exteroceptive (dermal, from mucose membrane)membrane)

Interoceptive (from mucosa membrane of Interoceptive (from mucosa membrane of internal organs – for example urination in internal organs – for example urination in case of internal sphincter irritation)case of internal sphincter irritation)

Motor SystemMotor SystemMotor SystemMotor System

Motor systemMotor system

Provides conduction of nervous impulse from Provides conduction of nervous impulse from brain cortex to muscles. brain cortex to muscles.

The way of this impulse is known as The way of this impulse is known as motorwaymotorway

or or tractus corticomuscularistractus corticomuscularis

It consists of two neurons: It consists of two neurons:

Central – Central – upper motor neuron (UMN)upper motor neuron (UMN)

Peripheral – Peripheral – lower motor neuron (LMN)lower motor neuron (LMN)

Upper and lower extremities, neck, trunk Upper and lower extremities, neck, trunk and perineum musclesand perineum muscles’’ innervation innervation

The The first (central) neuronfirst (central) neuron ((upper motor neuronupper motor neuron) ) is called is called Corticospinal tractCorticospinal tract tractus corticospinalistractus corticospinalis

The The second (peripheral) neuronsecond (peripheral) neuron ((lower motor neuronlower motor neuron)) is called is called Spinomuscular tractSpinomuscular tract tractus spinomuscularistractus spinomuscularis

Tractus corticomuscularisTractus corticomuscularis

Motor HomunculusMotor HomunculusMotor HomunculusMotor Homunculus

Upper Motor Neuron Corticospinal TractUpper Motor Neuron Corticospinal Tract Upper Motor Neuron Corticospinal TractUpper Motor Neuron Corticospinal Tract

Lower Motor NeuronLower Motor Neuron

cell body: anterior horncell body: anterior horn

axon: axon: anterior root,anterior root,

spinal nervespinal nerve

axon terminal:axon terminal:

neuromuscularneuromuscular

junctionjunction

Effector:Effector:skeletal muscleskeletal muscle

Lower Motor NeuronLower Motor Neuron

cell body: anterior horncell body: anterior horn

axon: axon: anterior root,anterior root,

spinal nervespinal nerve

axon terminal:axon terminal:

neuromuscularneuromuscular

junctionjunction

Effector:Effector:skeletal muscleskeletal muscle

Spinal nerve gives 4 branches:Spinal nerve gives 4 branches:

ramus anterior ( together they form plexus ramus anterior ( together they form plexus – cervical, brachial, lumbar and sacral)– cervical, brachial, lumbar and sacral)

ramus posterior (it is spinal nerve, which ramus posterior (it is spinal nerve, which innervates posterior trunk muscles)innervates posterior trunk muscles)

ramus meningeusramus meningeus

ramus comunicante albiramus comunicante albi

Conclusions:Conclusions:

The muscles of upper and lower The muscles of upper and lower extremities have unilateral cortical extremities have unilateral cortical innervation from contralateral hemisphere innervation from contralateral hemisphere

The muscles of neck, trunk and pelvic The muscles of neck, trunk and pelvic organs have bilateral innervation from both organs have bilateral innervation from both hemispheres. In case of unilateral hemispheres. In case of unilateral pathologic focus these structures do not pathologic focus these structures do not suffersuffer

Extremities, neck, trunk and Extremities, neck, trunk and perineum musclesperineum muscles’’ innervation innervation

Neurons of С1-С4 anterior roots – innervate neck musclesС5-Th1 – muscles of upper extremities Th2-Th12 – muscles of trunk L1-S2 – muscles of legs S3 – S5 – muscles of perineum

Face, tongue and pharynx Face, tongue and pharynx muscles innervationmuscles innervation

This way is called This way is called tractus corticomuscularistractus corticomuscularis

The The firstfirst central neuron central neuron

((upper motor neuronupper motor neuron))

is called is called tractus corticonuclearistractus corticonuclearis

((Corticobulbar TractCorticobulbar Tract))

The The secondsecond peripheral neuron peripheral neuron

((lower motor neuronlower motor neuron))

is called is called tractus nucleomuscularistractus nucleomuscularis

Face, tongue and pharynx muscles Face, tongue and pharynx muscles innervationinnervation

We can make the following conclusions:We can make the following conclusions:

The The face muscles have bilateral cortex face muscles have bilateral cortex innervationinnervation except the mimic muscles and except the mimic muscles and tongue muscles that have unilateral tongue muscles that have unilateral innervation from the opposite hemisphereinnervation from the opposite hemisphereThe muscles of The muscles of upper and lower extremities, upper and lower extremities, lower mimic muscles and tongue muscles lower mimic muscles and tongue muscles have unilateral cortical innervationhave unilateral cortical innervationAll the other muscles All the other muscles (the muscles of neck, (the muscles of neck, trunk, perineum, m. oculomotorial, m. trunk, perineum, m. oculomotorial, m. masseter, pharyngeal and palatal muscles) masseter, pharyngeal and palatal muscles) have bilateral cortical innervationhave bilateral cortical innervation

UMN and LMN Syndrome - ParalysisUMN and LMN Syndrome - ParalysisUMN and LMN Syndrome - ParalysisUMN and LMN Syndrome - Paralysis

ParalysisParalysisParalysis Paralysis (plegia)(plegia) - means the absence of - means the absence of active movements. It occurs in case of active movements. It occurs in case of complete lesion of complete lesion of motor waymotor way (tractus (tractus corticomuscularis) corticomuscularis)

ParesisParesis occurs in case of incomplete occurs in case of incomplete lesion of motor way. That means disorders lesion of motor way. That means disorders of active movementsof active movements

Clinically can be – hemi-, tetra-, mono-, tri- Clinically can be – hemi-, tetra-, mono-, tri- and paraparesisand paraparesis

Paralysis is divided into:Paralysis is divided into:

Central (spastic)Central (spastic)Peripheral (flaccid)Peripheral (flaccid)

CentralCentral or spastic paralysis is caused by the or spastic paralysis is caused by the lesion of central neuron and its fibers (tr. lesion of central neuron and its fibers (tr. corticospinalis or tr. corticonuclearis)corticospinalis or tr. corticonuclearis)

PeripheralPeripheral or flaccid paralysis is caused by or flaccid paralysis is caused by the lesion of peripheral neuron (tractus the lesion of peripheral neuron (tractus spinomuscularis or tractus spinomuscularis or tractus nucleomuscularis)nucleomuscularis)

Features of central (spastic) Features of central (spastic) paralysis are:paralysis are:

1.1. HyperreflexionHyperreflexion of Deep Tendon reflexes of Deep Tendon reflexes 2.2. SpasticitySpasticity of skeletal muscles of skeletal muscles 3.3. Pathologic reflexesPathologic reflexes. They are considered . They are considered

to be reliable signs of central paralysis to be reliable signs of central paralysis 4.4. It is a diffuse paralysisIt is a diffuse paralysis5.5. Protective reflexes (the reflexes of spinal Protective reflexes (the reflexes of spinal

automatism)automatism)6.6. Pathologic synkinesisPathologic synkinesis is involuntary is involuntary

movements in paralysed extremity movements in paralysed extremity

Spastic hypertonus (Vernike-Mann posture)Spastic hypertonus (Vernike-Mann posture)

Spastic hypertonus features:Spastic hypertonus features:

Tonus is increased in the group of flexors Tonus is increased in the group of flexors in upper extremities and in the group of in upper extremities and in the group of extensors in lower extremitiesextensors in lower extremities

““Clasp – knife“ Clasp – knife“ Phenomenon

in course of evaluation tonus decreasesin course of evaluation tonus decreases

Spastic hypertonus in legSpastic hypertonus in leg

Planter responseNormalNormal Pathologic Pathologic

Features of peripheral paralysisFeatures of peripheral paralysis

1. 1. AreflexionAreflexion or hyporeflexion or hyporeflexion

2. 2. AtoniaAtonia or hypotonia or hypotonia

3. Muscular 3. Muscular atrophyatrophy

4. Fasciculation of muscles4. Fasciculation of muscles

5. It is limited paralysis 5. It is limited paralysis

6. There is reaction of degeneration6. There is reaction of degeneration

Global Global wasting of wasting of the left arm the left arm in a post-in a post-traumatic traumatic brachial brachial

plexopathyplexopathy

Muscular AtrophyMuscular AtrophyMuscular AtrophyMuscular Atrophy

Wasting of the tongueWasting of the tongue

Note any of the following common gait disorders:

Hemiplegic gait with one-sided weakness - a possible sign of cerebral stroke

Spastic gait - a possible sign of cerebral palsy

Ataxic gait - a possible indication of cerebellar dysfunction

Festinating gait - a possible sign of Parkinson's disease

Bare test (upper)Bare test (upper)

Bare test (upper)Bare test (upper)

Bare test (lower)Bare test (lower)

Mandibular reflexMandibular reflex

Palatal reflexPalatal reflex

Biceps reflexBiceps reflex

Triceps reflexTriceps reflex

Carpo-radial reflexCarpo-radial reflex

Knee reflexKnee reflex

Ankle reflexAnkle reflex