Sensory System SystemSensory System System

Nabeel Kouka, MD, DO, MBA

www.brain101.infoNabeel Kouka, MD, DO, MBA

www.brain101.info

environmentenvironmentenvironmentenvironment

animalanimalorganismorganism

animalanimalorganismorganism

Nervous systemNervous system

sensory sensory neuronneuron

stimulus reactionreaction

effectoreffectorInter-Inter-

neuronneuronreceptorreceptorMotorMotor

neuronneuron

Nervous System stimulus and reaction Nervous System stimulus and reaction

Sensory SystemSensory System

Modality of SensationModality of Sensation

ReceptorReceptor

Sensory TractSensory Tract

Primary NeuronPrimary Neuron Secondary NeuronSecondary Neuron Tertiary NeuronTertiary Neuron TerminationTermination

Modality of SensationModality of Sensation

General Sensation,General Sensation, Special Sensation Special Sensation

vision, hearing, equilibrium, smell, tastevision, hearing, equilibrium, smell, taste

Exteroception, Interoception,Exteroception, Interoception, ProprioceptionProprioception

conscious vs. unconscious proprioceptionconscious vs. unconscious proprioception

position sensation, kinesthesia position sensation, kinesthesia

Touch, Touch, Pain,Pain, Temperature SensationTemperature Sensation

discriminative vs. light touch sensationdiscriminative vs. light touch sensation

fast vs. slow painfast vs. slow pain

ReceptorsReceptors

Peripheral Nerve EndingPeripheral Nerve Ending

Receptor NeuronReceptor Neuron

Olfactory Neuron of Olfactory EpitheliumOlfactory Neuron of Olfactory Epithelium

Specialized Receptor CellSpecialized Receptor Cell

Merkel cell of EpdermisMerkel cell of Epdermis

Taste (Gustatory, Clear) Cell of Taste BudTaste (Gustatory, Clear) Cell of Taste Bud

Photoreceptor cells of RetinaPhotoreceptor cells of Retina

Hair cells of Inner EarHair cells of Inner Ear

Receptor: Peripheral Nerve EndingsReceptor: Peripheral Nerve Endings

Receptor Neurons of Craniospinal Ganglion Pseudounipolar neurons of dorsal root ganglia

Trigeminal (semilunar, Gasserian ganglion),

geniculate (VII), superior IX, superior X ganglia (GSA)

Geniculate (VII), inferior IX, inferior X ganglia (VA)

Morphological Classification Free nerve endings

Expanded tip endings

Encapsulated endings ----- CT envestment

ReceptorsReceptors

Free Nerve EndingsFree Nerve Endings

- Nerve endings without special structural- Nerve endings without special structural

organizationorganization

- - pain and temperaturepain and temperature receptor receptor

Expanded Tip EndingsExpanded Tip Endings - - Merkel’s Touch CorpuscleMerkel’s Touch Corpuscle

Merkel cells in basal layer of epidermisMerkel cells in basal layer of epidermis

- - Type I Hair cellsType I Hair cells of Vestibular Labyrinth of Vestibular Labyrinth

ReceptorsReceptors

Encapsulated EndingsEncapsulated Endings

- Meissner’s Corpuscle- Meissner’s Corpuscle

- Pacinian Corpuscle- Pacinian Corpuscle

(Corpuscle of Vater-Pacini)(Corpuscle of Vater-Pacini)

- Genital Corpuscle- Genital Corpuscle

- Ruffini’s Ending- Ruffini’s Ending

- End Bulb of Krause- End Bulb of Krause

- - Golgi tendon organ:Golgi tendon organ: ProprioceptorProprioceptor

Receptor Endings Free nerve

ending

Expanded tip

ending

Encapsulated

ending

• Both receptor and effectorBoth receptor and effector

• StructureStructure

1. Capsule1. Capsule

2. Intrafusal Muscle Fibers2. Intrafusal Muscle Fibers

- Nuclear Bag Fiber- Nuclear Bag Fiber - Nuclear Chain Fiber- Nuclear Chain Fiber

3. Receptor and Effector Nerve Endings3. Receptor and Effector Nerve Endings

- Afferent Ending- Afferent Ending - Efferent Ending- Efferent Ending

Neuromuscular SpindleNeuromuscular SpindleNeuromuscular SpindleNeuromuscular Spindle

• INTRAFUSAL MUSCLE FIBERSINTRAFUSAL MUSCLE FIBERS

(1) Nuclear Bag Fiber(1) Nuclear Bag Fiber

- 1-4 / each spindle- 1-4 / each spindle

- longer and thicker than nuclear chain fiber- longer and thicker than nuclear chain fiber

- large central aggregation of nucleus in- large central aggregation of nucleus in

equatorial regionequatorial region

(2) Nuclear Chain Fiber(2) Nuclear Chain Fiber - many fibers / spindle- many fibers / spindle - smaller and thinner than nuclear bag fiber- smaller and thinner than nuclear bag fiber - central row of nucleus in equatorial region- central row of nucleus in equatorial region

Neuromuscular (Muscle) SpindleNeuromuscular (Muscle) SpindleNeuromuscular (Muscle) SpindleNeuromuscular (Muscle) Spindle

• INNERVATIONINNERVATION

Afferent Fibers: ProprioceptorsAfferent Fibers: Proprioceptors

(1) Primary (Annulospiral) Endings(1) Primary (Annulospiral) Endings

- Group Ia (12-20 - Group Ia (12-20 m in diameter) afferentsm in diameter) afferents

- terminate in both NB and NC fibers- terminate in both NB and NC fibers

- wound around the central equatorial region- wound around the central equatorial region

(2) Secondary (Flower-Spray) Endings(2) Secondary (Flower-Spray) Endings - group II (6-8 - group II (6-8 m in diameter) afferentm in diameter) afferent - terminates predominantly in nuclear chain fiber- terminates predominantly in nuclear chain fiber - terminates around juxtaequatorial region- terminates around juxtaequatorial region

Neuromuscular (Muscle) SpindleNeuromuscular (Muscle) SpindleNeuromuscular (Muscle) SpindleNeuromuscular (Muscle) Spindle

• INNERVATIONINNERVATION

Efferent FibersEfferent Fibers

Gamma (Gamma () Motor Fiber) Motor Fiber

- terminates in small motor end plates- terminates in small motor end plates

of the non-nucleated (striated) /regionof the non-nucleated (striated) /region

of both intrafusal muscle fibers of both intrafusal muscle fibers

Neuromuscular (Muscle) SpindleNeuromuscular (Muscle) SpindleNeuromuscular (Muscle) SpindleNeuromuscular (Muscle) Spindle

Sensory System Sensory System General SensationGeneral Sensation

Sensory System Sensory System General SensationGeneral Sensation

Pathways for General SensationPathways for General Sensation

Touch & Proprioception from bodyTouch & Proprioception from body

Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway

Pain & Temperature from bodyPain & Temperature from body

Spinothalamic TractSpinothalamic Tract

cf. Spinoreticular or Spinoreticulothalamic Tractcf. Spinoreticular or Spinoreticulothalamic Tract

General Sensation from FaceGeneral Sensation from Face

Trigeminothalamic TractsTrigeminothalamic Tracts

Pathways for General SensationPathways for General Sensation

Touch & Proprioception from bodyTouch & Proprioception from body

Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway

Pain & Temperature from bodyPain & Temperature from body

Spinothalamic TractSpinothalamic Tract

cf. Spinoreticular or Spinoreticulothalamic Tractcf. Spinoreticular or Spinoreticulothalamic Tract

General Sensation from FaceGeneral Sensation from Face

Trigeminothalamic TractsTrigeminothalamic Tracts

Sensory System Sensory System General Sensation General Sensation Sensory System Sensory System General Sensation General Sensation

Modality: Modality: Discriminative Touch Sensation (include Vibration) and Discriminative Touch Sensation (include Vibration) and Conscious Proprioception (Position Sensation, Kinesthesia)Conscious Proprioception (Position Sensation, Kinesthesia) from bodyfrom body

Receptor: Receptor: Most receptors except free nerve endingsMost receptors except free nerve endings

1st Neuron: 1st Neuron: Dorsal Root GanglionDorsal Root Ganglion

Posterior White ColumnPosterior White Column

2nd Neuron: 2nd Neuron: Dorsal Column NucleiDorsal Column Nuclei (Nucleus Gracilis et Cuneatus)(Nucleus Gracilis et Cuneatus)

Internal Arcuate Fiber - Lemniscal Decussation - Medial LemniscusInternal Arcuate Fiber - Lemniscal Decussation - Medial Lemniscus

3rd Neuron: 3rd Neuron: Thalamus (VPLc)Thalamus (VPLc)

Internal Capsule ----- Corona RadiataInternal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

Modality: Modality: Discriminative Touch Sensation (include Vibration) and Discriminative Touch Sensation (include Vibration) and Conscious Proprioception (Position Sensation, Kinesthesia)Conscious Proprioception (Position Sensation, Kinesthesia) from bodyfrom body

Receptor: Receptor: Most receptors except free nerve endingsMost receptors except free nerve endings

1st Neuron: 1st Neuron: Dorsal Root GanglionDorsal Root Ganglion

Posterior White ColumnPosterior White Column

2nd Neuron: 2nd Neuron: Dorsal Column NucleiDorsal Column Nuclei (Nucleus Gracilis et Cuneatus)(Nucleus Gracilis et Cuneatus)

Internal Arcuate Fiber - Lemniscal Decussation - Medial LemniscusInternal Arcuate Fiber - Lemniscal Decussation - Medial Lemniscus

3rd Neuron: 3rd Neuron: Thalamus (VPLc)Thalamus (VPLc)

Internal Capsule ----- Corona RadiataInternal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway

DRG: Dorsal Root GanglionDRG: Dorsal Root Ganglion

1. 1. Posterior White ColumnPosterior White Column

A. Nucleus gracilisA. Nucleus gracilis

B. Nucleus cuneatusB. Nucleus cuneatus

2. 2. Medial LemniscusMedial Lemniscus

3. 3. Corona Radiata Corona Radiata

C. Thalamus (VPLc)C. Thalamus (VPLc)

D. Cerebral Cortex (S I)D. Cerebral Cortex (S I)

Posterior White Posterior White

Column-Medial Column-Medial

Lemniscal PathwayLemniscal Pathway

DRG

D

Peripheral NervePeripheral Nerve

DRG (dorsal root ganglion) neuronDRG (dorsal root ganglion) neuron

pseudounipolar cellpseudounipolar cell

peripheralperipheralprocessprocess

centralcentralprocessprocess

telodendrontelodendrontelodendrontelodendron

cell body cell body in DRGin DRG

NG: Nucleus GracilisNG: Nucleus Gracilis

NC: Nucleus CuneatusNC: Nucleus Cuneatus

IAF: internal arcuateIAF: internal arcuate fiberfiber

LD: lemniscal LD: lemniscal decussationdecussation

ML: medial lemniscusML: medial lemniscus

PWC-MLPWC-ML

PathwayPathway

SecondarySecondaryNeuronNeuron

PWC-MLPWC-ML

PathwayPathway

SecondarySecondaryNeuronNeuron

Thalamus

Ventral Posteromedial

(VPL) Nucleus

SensorySensoryHomunculusHomunculus

SensorySensoryHomunculusHomunculus

Pain PathwayPain Pathway

Spinothalamic TractSpinothalamic Tract

Anteromedial SystemAnteromedial System

Pain PathwayPain Pathway Pain PathwayPain Pathway

PeripheralPeripheral

chemical chemical

mediators ofmediators of

pain and pain and

hyperalgesiahyperalgesia

• histaminehistamine

• bradykininbradykinin

• prostaglandinsprostaglandins

• potassium (Kpotassium (K++))

Modality: Modality: Pain & Temperature Sensation, Pain & Temperature Sensation, Light Touch Light Touch from bodyfrom body

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

1st Neuron: 1st Neuron: Dorsal Root GanglionDorsal Root Ganglion

2nd Neuron: 2nd Neuron: Dorsal Horn Dorsal Horn (Lamina I, IV, V)(Lamina I, IV, V)

Anterior White CommissureAnterior White Commissure

Spinothalamic Tract (Spinal Lemniscus) Spinothalamic Tract (Spinal Lemniscus)

3rd Neuron: 3rd Neuron: Thalamus (VPLc & CL)Thalamus (VPLc & CL) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

Modality: Modality: Pain & Temperature Sensation, Pain & Temperature Sensation, Light Touch Light Touch from bodyfrom body

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

1st Neuron: 1st Neuron: Dorsal Root GanglionDorsal Root Ganglion

2nd Neuron: 2nd Neuron: Dorsal Horn Dorsal Horn (Lamina I, IV, V)(Lamina I, IV, V)

Anterior White CommissureAnterior White Commissure

Spinothalamic Tract (Spinal Lemniscus) Spinothalamic Tract (Spinal Lemniscus)

3rd Neuron: 3rd Neuron: Thalamus (VPLc & CL)Thalamus (VPLc & CL) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

Spinothalamic TractSpinothalamic Tract Spinothalamic TractSpinothalamic Tract

Spinothalamic TractSpinothalamic Tract Spinothalamic TractSpinothalamic Tract

Modality: Modality: Pain & Temperature Sensation, Pain & Temperature Sensation,

Light Touch Light Touch from bodyfrom body

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

1st Neuron: 1st Neuron: Dorsal Root Ganglion Dorsal Root Ganglion

2nd Neuron: 2nd Neuron: Dorsal Horn Dorsal Horn (Lamina I, IV, V)(Lamina I, IV, V)

Anterior White CommissureAnterior White Commissure

Spinothalamic Tract (Spinal Lemniscus) Spinothalamic Tract (Spinal Lemniscus)

3rd Neuron: 3rd Neuron: Reticular FormationReticular Formation

4rd Neuron: 4rd Neuron: Thalamus (CL, Sm, POm)Thalamus (CL, Sm, POm) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Diffuse Cerebral CotexDiffuse Cerebral Cotex

Modality: Modality: Pain & Temperature Sensation, Pain & Temperature Sensation,

Light Touch Light Touch from bodyfrom body

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

1st Neuron: 1st Neuron: Dorsal Root Ganglion Dorsal Root Ganglion

2nd Neuron: 2nd Neuron: Dorsal Horn Dorsal Horn (Lamina I, IV, V)(Lamina I, IV, V)

Anterior White CommissureAnterior White Commissure

Spinothalamic Tract (Spinal Lemniscus) Spinothalamic Tract (Spinal Lemniscus)

3rd Neuron: 3rd Neuron: Reticular FormationReticular Formation

4rd Neuron: 4rd Neuron: Thalamus (CL, Sm, POm)Thalamus (CL, Sm, POm) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Diffuse Cerebral CotexDiffuse Cerebral Cotex

Spinoreticulothalamic TractSpinoreticulothalamic Tract (Paleospinothalamic Tract)(Paleospinothalamic Tract) Spinoreticulothalamic TractSpinoreticulothalamic Tract (Paleospinothalamic Tract)(Paleospinothalamic Tract)

Spinothalamic TractSpinothalamic TractSpinothalamic TractSpinothalamic Tract

spinothalamicspinothalamictracttract

anterior whiteanterior whitecommissurecommissure

posterior rootposterior root

decussationdecussation

- - contralateralcontralateral loss of pain and temperature loss of pain and temperature sensation sensation below below the level of lesionthe level of lesion

DRG: Dorsal Root GanglionDRG: Dorsal Root Ganglion

A. Spinal Dorsal HornA. Spinal Dorsal Horn

B. Reticular FormationB. Reticular Formation

1. 1. Neospinothalamic TractNeospinothalamic Tract

2. 2. Paleospinothalamic TractPaleospinothalamic Tract

C. Thalamus (VPLc, CL)C. Thalamus (VPLc, CL)

3. 3. Corona RadiataCorona Radiata

D. Cerebral Cortex (S I)D. Cerebral Cortex (S I)

Spinothalamic TractSpinothalamic Tract

Anteromedial SystemAnteromedial System

DRG

D

Fast PainFast Pain Slow PainSlow Pain

Sharp, prickingSharp, pricking Dull, burningDull, burning

Group III (AGroup III (A) fiber) fiber Group IV (C) fiberGroup IV (C) fiber

Short latencyShort latency Slower onsetSlower onset

Well localizedWell localized DiffuseDiffuse

Short durationShort duration Long durationLong duration

Less emotional Less emotional Emotional, autonomic responseEmotional, autonomic response

Not blocked by morphineNot blocked by morphine Blocked by morphineBlocked by morphine

Neospinothalamic TractNeospinothalamic Tract Paleospinothalamic TractPaleospinothalamic Tract

Comparison of Fast and Slow PainComparison of Fast and Slow Pain ------ Spinothalamic Tract------ Spinothalamic Tract Comparison of Fast and Slow PainComparison of Fast and Slow Pain ------ Spinothalamic Tract------ Spinothalamic Tract

Fast and Slow PainFast and Slow Pain

Comparison of Comparison of

Fast and Slow PainFast and Slow Pain

Neospinothalamic TractNeospinothalamic Tract

Paleospinothalamic tractPaleospinothalamic tract

- spinoreticular tract- spinoreticular tract

- spinoreticulothalamic- spinoreticulothalamic

tracttract

1. Ascending control1. Ascending control

““Gate control theory”Gate control theory” of Wall and Melzak (1965) of Wall and Melzak (1965)

Substantia gelatinosa RolandiSubstantia gelatinosa Rolandi

2. Descending Control2. Descending Control

““Stimulation produced analgesia (SPA)”Stimulation produced analgesia (SPA)”

Raphe Magnus ------------Raphe Magnus ------------ Raphespinal tract (Serotonin)Raphespinal tract (Serotonin)

Periaqueductal Gray -----Periaqueductal Gray ----- fibers to raphe magnusfibers to raphe magnus

Lateral Tegmental Nucleus (Epinephrine)Lateral Tegmental Nucleus (Epinephrine)

Substantia gelatinosa RolandiSubstantia gelatinosa Rolandi

enkephalin enkephalin cf. endorphine, morphinecf. endorphine, morphine

Control of Pain TransmissionControl of Pain Transmission Control of Pain TransmissionControl of Pain Transmission

Spinal and Brain StemSpinal and Brain Stem

Control of PainControl of Pain

Analgesia - Analgesia - Morphine and EnkephalinMorphine and Enkephalin Analgesia - Analgesia - Morphine and EnkephalinMorphine and Enkephalin

opiumopium

Modality: Modality: General SensationGeneral Sensation from facefrom face

Receptor: Receptor: Most receptors in the face Most receptors in the face

1st Neuron: 1st Neuron: Trigeminal (Semilunar) GangliaTrigeminal (Semilunar) Ganglia

2nd Neuron: 2nd Neuron: Trigeminal Sensory NucleusTrigeminal Sensory Nucleus pain & temperature pain & temperature ---- pars caudalis of ---- pars caudalis of

spinal tract nucleus of Vspinal tract nucleus of V

Ventral and Dorsal Trigeminothalamic TractVentral and Dorsal Trigeminothalamic Tract

3rd Neuron: 3rd Neuron: Thalamus (VPM)Thalamus (VPM) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

Modality: Modality: General SensationGeneral Sensation from facefrom face

Receptor: Receptor: Most receptors in the face Most receptors in the face

1st Neuron: 1st Neuron: Trigeminal (Semilunar) GangliaTrigeminal (Semilunar) Ganglia

2nd Neuron: 2nd Neuron: Trigeminal Sensory NucleusTrigeminal Sensory Nucleus pain & temperature pain & temperature ---- pars caudalis of ---- pars caudalis of

spinal tract nucleus of Vspinal tract nucleus of V

Ventral and Dorsal Trigeminothalamic TractVentral and Dorsal Trigeminothalamic Tract

3rd Neuron: 3rd Neuron: Thalamus (VPM)Thalamus (VPM) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

Trigeminothalamic Tract Trigeminothalamic Tract Trigeminothalamic Tract Trigeminothalamic Tract

Trigeminothalamic Trigeminothalamic TractTract

A. trigeminal ganglionA. trigeminal ganglionB. trigeminal sensory B. trigeminal sensory nucleusnucleusC. thalamus (VPM)C. thalamus (VPM)D. cerebral cortex (S I)D. cerebral cortex (S I)

1. 1. spinal tract of spinal tract of trigeminal nervetrigeminal nerve2. 2. ventral ventral trigeminothalamic tracttrigeminothalamic tract3. 3. dorsal dorsal trigeminothalamic tracttrigeminothalamic tract4. 4. corona radiatacorona radiataV.V. trigeminal nerve trigeminal nerve

Thalamus

Ventral Posteromedial

(VPM) Nucleus

Spinothalamic TractSpinothalamic Tract& Spinoreticular Tract& Spinoreticular Tract

Widespread Widespread cortical regioncortical region

CL (intralaminarCL (intralaminar thalamic nuclei)thalamic nuclei)

reticulothalamicreticulothalamic pathwayspathways

spinoreticularspinoreticular tracttract

Primary MotorPrimary Motor Area (M I)Area (M I)

VPLc (ventrobasalVPLc (ventrobasal nuclear complex)nuclear complex)

(spinal lemniscus)(spinal lemniscus)

spinothalamicspinothalamic tracttract

thalamus

reticularformation

NeoSTTNeoSTT PaleoSTTPaleoSTT

Spinocerebellar TractSpinocerebellar Tract

Modality: Modality: Unconscious Proprioception Unconscious Proprioception

Receptor: Receptor: Muscle spindle, Golgi tendon organMuscle spindle, Golgi tendon organ

1st Neuron: 1st Neuron: Dorsal Root Ganglion Dorsal Root Ganglion

Posterior Root , [Posterior Column] Posterior Root , [Posterior Column]

2nd Neuron: 2nd Neuron: 1. Clarke’s column 1. Clarke’s column Posterior Spinocerebellar TractPosterior Spinocerebellar Tract

2. Accessory Cuneate Nucleus2. Accessory Cuneate Nucleus Cuneocerebellar Tract Cuneocerebellar Tract

3. Posterior Horn3. Posterior Horn Anterior Spinocerebellar r TractAnterior Spinocerebellar r Tract

Termination: Termination: Cerebellar CortexCerebellar Cortex

Spinal Cord Ascending TractsSpinal Cord Ascending Tracts Spinal Cord Ascending TractsSpinal Cord Ascending Tracts

Spinocerebellar TractSpinocerebellar Tract

Spinocerebellar TractSpinocerebellar TractSpinocerebellar TractSpinocerebellar Tract

Posterior SCbllTPosterior SCbllT

Inferior Inferior cerebellarcerebellar pedunclepeduncle

Post. SCbllT andPost. SCbllT and cuneocerebellarcuneocerebellar tracttract

posteriorposterior white columnwhite column

posterior rootposterior root

Anterior SCbllTAnterior SCbllT

superiorsuperior cerebellarcerebellar pedunclepeduncle

anterioranterior spinocerebellarspinocerebellar tracttract

anterior whiteanterior white commissurecommissure

posterior rootposterior root

Predominant Sensory SyndromesPredominant Sensory Syndromes Predominant Sensory SyndromesPredominant Sensory Syndromes

• Herpes ZosterHerpes Zoster - inflammatory reactions of dorsal root ganglion- inflammatory reactions of dorsal root ganglion - severe pain on the dermatomes of affected ganglion- severe pain on the dermatomes of affected ganglion followed by rashes and vesiclefollowed by rashes and vesicle

• Tabes DorsalisTabes Dorsalis - common variety of neurosyphilis- common variety of neurosyphilis - posterior colum and spinal posterior root lesion- posterior colum and spinal posterior root lesion - loss of discriminative touch sensation and conscious- loss of discriminative touch sensation and conscious proprioception below the level of lesionproprioception below the level of lesion - posterior column ataxia- posterior column ataxia - lancinating pain- lancinating pain - loss of deep tendon reflex (DTR)- loss of deep tendon reflex (DTR)

Herpes Zoster (Shingles)Herpes Zoster (Shingles)• varicella-zoster virusvaricella-zoster virus reactivation from reactivation from the dorsal root gangliathe dorsal root ganglia

• unilateral vesicular unilateral vesicular eruption within eruption within a dermatomea dermatome

• T3 to L3 dermatome T3 to L3 dermatome lesions are frequentlesions are frequent

• zoster ophtahalmicus zoster ophtahalmicus (ophthalmic division(ophthalmic division of trigeminal n., Vof trigeminal n., V11))

• Ramsey-Hunt syndromeRamsey-Hunt syndrome (sensory br. of VII)(sensory br. of VII)

• acyclovir, antiviral agentacyclovir, antiviral agent

Herpes Zoster Herpes Zoster (Shingles)(Shingles)

Herpes Zoster Herpes Zoster (Shingles)(Shingles) Zoster ophthalmicusZoster ophthalmicusZoster ophthalmicusZoster ophthalmicus

Tabes Dorsalis (Neurosyphilis)Tabes Dorsalis (Neurosyphilis)

posterior column lesion - sensory symptoms, posterior column ataxiaposterior column lesion - sensory symptoms, posterior column ataxia

Tabes DorsalisTabes Dorsalis

Subacute Combined Subacute Combined

DegenerationDegeneration

Ataxic Gait and Position: Ataxic Gait and Position:

- Watches the ground- Watches the ground in walkingin walking

- Positive Romberg Test- Positive Romberg Test

- Stick and Stamp Sign- Stick and Stamp Sign

Posterior ColumnPosterior Column

AtaxiaAtaxia

Posterior ColumnPosterior Column

AtaxiaAtaxia

Friedreich’s AtaxiaFriedreich’s Ataxia

posterior spinocerebellar tract lesion - cerebellar ataxiaposterior spinocerebellar tract lesion - cerebellar ataxia

Muscle Status - Balance and PostureMuscle Status - Balance and Posture

alcohol and cerebellar dysfunctionalcohol and cerebellar dysfunction

SyringomyeliaSyringomyeliaSyringomyeliaSyringomyelia

initial symptom - bilateral loss of pain and temperature sensationinitial symptom - bilateral loss of pain and temperature sensation

SyringomyeliaSyringomyeliaSyringomyeliaSyringomyelia

initial symptom - bilateral loss of pain and temperature sensationinitial symptom - bilateral loss of pain and temperature sensation

Trigeminal NeuralgiaTrigeminal Neuralgia(tic douloureux)(tic douloureux)

- - excruciating episodic painexcruciating episodic pain

in the area supplied by in the area supplied by

trigeminal nerve, especiallytrigeminal nerve, especially

second and third divisionsecond and third division

- - trigger pointtrigger point

- intense pain makes the- intense pain makes the

patient grimace (tic)patient grimace (tic)

- - antiepileptic drugantiepileptic drug (phenytoin, (phenytoin,

carbamazepinecarbamazepine) is effective) is effective

- surgical treatment- surgical treatment

Special SensationSpecial Sensation

Gustatory Sensation (Taste, SVA) Gustatory Sensation (Taste, SVA) ----- Taste Pathway----- Taste Pathway Auditory Sensation (Hearing, SSA) Auditory Sensation (Hearing, SSA) ----- Auditory Pathway----- Auditory Pathway Vestibular Sensation (Equilibrium, SSA)Vestibular Sensation (Equilibrium, SSA) ----- Vestibular Pathway----- Vestibular Pathway Vision (SSA)Vision (SSA) ----- Visual Pathway----- Visual Pathway Olfaction (Smell, SVA)Olfaction (Smell, SVA) ----- Olfactory Pathway----- Olfactory Pathway

Special SensationSpecial Sensation

Gustatory Sensation (Taste, SVA) Gustatory Sensation (Taste, SVA) ----- Taste Pathway----- Taste Pathway Auditory Sensation (Hearing, SSA) Auditory Sensation (Hearing, SSA) ----- Auditory Pathway----- Auditory Pathway Vestibular Sensation (Equilibrium, SSA)Vestibular Sensation (Equilibrium, SSA) ----- Vestibular Pathway----- Vestibular Pathway Vision (SSA)Vision (SSA) ----- Visual Pathway----- Visual Pathway Olfaction (Smell, SVA)Olfaction (Smell, SVA) ----- Olfactory Pathway----- Olfactory Pathway

Sensory System Sensory System Special Sensation Special Sensation Sensory System Sensory System Special Sensation Special Sensation

Taste (Gustatory) Taste (Gustatory)

PathwayPathway

Taste (Gustatory) Taste (Gustatory)

PathwayPathway

Modality: Modality: Taste Sensation Taste Sensation

Receptor: Receptor: Taste BudTaste Bud

Cranial Nerve: VII, IX, XCranial Nerve: VII, IX, X

1st Neuron: 1st Neuron: Geniculate Ganglion (VII)Geniculate Ganglion (VII)

Inferior Ganglion (IX, X)Inferior Ganglion (IX, X)

2nd Neuron: 2nd Neuron: Nucleus Tractus SolitariusNucleus Tractus Solitarius

(Gustatory Nucleus)(Gustatory Nucleus)

solitariothalamic fiber (central tegmental tract) solitariothalamic fiber (central tegmental tract)

3rd Neuron: 3rd Neuron: Thalamus (VPMpc)Thalamus (VPMpc) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Gustatory AreaGustatory Area Brodmann area 43 & parainsular cortexBrodmann area 43 & parainsular cortex

Modality: Modality: Taste Sensation Taste Sensation

Receptor: Receptor: Taste BudTaste Bud

Cranial Nerve: VII, IX, XCranial Nerve: VII, IX, X

1st Neuron: 1st Neuron: Geniculate Ganglion (VII)Geniculate Ganglion (VII)

Inferior Ganglion (IX, X)Inferior Ganglion (IX, X)

2nd Neuron: 2nd Neuron: Nucleus Tractus SolitariusNucleus Tractus Solitarius

(Gustatory Nucleus)(Gustatory Nucleus)

solitariothalamic fiber (central tegmental tract) solitariothalamic fiber (central tegmental tract)

3rd Neuron: 3rd Neuron: Thalamus (VPMpc)Thalamus (VPMpc) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Gustatory AreaGustatory Area Brodmann area 43 & parainsular cortexBrodmann area 43 & parainsular cortex

Taste (Gustatory) PathwayTaste (Gustatory) Pathway Taste (Gustatory) PathwayTaste (Gustatory) Pathway

Taste BudTaste Bud

SVA (Special Visceral Afferent): Cranial Nerve VII, IX, XSVA (Special Visceral Afferent): Cranial Nerve VII, IX, X

Taste PathwaysTaste Pathways

A. nucleus tractusA. nucleus tractus solitariussolitarius (gustatory nucleus)(gustatory nucleus)B. thalamus (VPMpc)B. thalamus (VPMpc)C. Brodmann area 43C. Brodmann area 43D. parainsular cortexD. parainsular cortexE. parabrachialE. parabrachial nucleusnucleus

1. 1. solitariothalamicsolitariothalamic fiber (central fiber (central tegmental tract)tegmental tract)2. 2. corona radiatacorona radiataVII. VII. facial nervefacial nerveIX. IX. glossopharyngeal glossopharyngeal nervenerveX. X. vagus nervevagus nerve

Vestibular Vestibular

PathwayPathway

Vestibular Vestibular

PathwayPathway

Sense of EquilibriumSense of Equilibrium

Modality: Modality: Equilibrium Sensation Equilibrium Sensation

Receptor: Receptor: Macula & Crista Ampullaris Macula & Crista Ampullaris

Cranial Nerve: VIIIvCranial Nerve: VIIIv

1st Neuron: 1st Neuron: Vestibular GanglionVestibular Ganglion

2nd Neuron: 2nd Neuron: Vestibular NucleusVestibular Nucleus vestibulothalamic fiber (medial lemniscus) vestibulothalamic fiber (medial lemniscus)

3rd Neuron: 3rd Neuron: Thalamus (VPLo, VPI?)Thalamus (VPLo, VPI?) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Vestibular AreaPrimary Vestibular Area ----- Primary Somesthetic Area ----- Primary Somesthetic Area

(Brodmann area 3a, 2v ) (Brodmann area 3a, 2v )

Modality: Modality: Equilibrium Sensation Equilibrium Sensation

Receptor: Receptor: Macula & Crista Ampullaris Macula & Crista Ampullaris

Cranial Nerve: VIIIvCranial Nerve: VIIIv

1st Neuron: 1st Neuron: Vestibular GanglionVestibular Ganglion

2nd Neuron: 2nd Neuron: Vestibular NucleusVestibular Nucleus vestibulothalamic fiber (medial lemniscus) vestibulothalamic fiber (medial lemniscus)

3rd Neuron: 3rd Neuron: Thalamus (VPLo, VPI?)Thalamus (VPLo, VPI?) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Vestibular AreaPrimary Vestibular Area ----- Primary Somesthetic Area ----- Primary Somesthetic Area

(Brodmann area 3a, 2v ) (Brodmann area 3a, 2v )

Vestibular PathwayVestibular Pathway Vestibular PathwayVestibular Pathway

Vestibular Mechanism - Otolithic MembraneVestibular Mechanism - Otolithic Membrane Vestibular Mechanism - Otolithic MembraneVestibular Mechanism - Otolithic Membrane

Vestibular Hair CellVestibular Hair Cell Vestibular ReceptorVestibular Receptor Vestibular Hair CellVestibular Hair Cell Vestibular ReceptorVestibular Receptor

Vestibular PathwayVestibular Pathway

A. Vestibular ganglionA. Vestibular ganglion

B. Vestibular nucleusB. Vestibular nucleus

C. ThalamusC. Thalamus

(VPLo, VPI?)(VPLo, VPI?)

D. Primary VestibularD. Primary Vestibular

Area (S I, Brodman Area (S I, Brodman

area 3a, 2v)area 3a, 2v)

1. 1. Vestibulothalamic fiberVestibulothalamic fiber

(medial lemniscus)(medial lemniscus)

2. 2. Thalamocortical fiberThalamocortical fiber

(corona radiata)(corona radiata)

VIIIc: VIIIc: Vestibular divisionVestibular division

of VIIIth nerveof VIIIth nerve

VestibularVestibular

TerminationTermination

• ThalmocorticalThalmocortical

connectionconnection

(VPLo (VPLo S I)S I)

• Deep, PeripheralDeep, Peripheral

Somesthetic CortexSomesthetic Cortex

--- 3a, 2--- 3a, 2

(termination of (termination of

deep PWC-MLdeep PWC-ML

pathway)pathway)

AuditoryAuditory

PathwayPathway

Modality: Modality: Auditory Sensation (Hearing) Auditory Sensation (Hearing) Receptor: Receptor: Organ of Corti of Cochlear DuctOrgan of Corti of Cochlear Duct Cranial Nerve: VIIIcCranial Nerve: VIIIc

1st Neuron: 1st Neuron: Spiral GanglionSpiral Ganglion 2nd Neuron: 2nd Neuron: Cochlear Nucleus, Ventral & DorsalCochlear Nucleus, Ventral & Dorsal dorsal, intermediate and ventral acoustic striae dorsal, intermediate and ventral acoustic striae trapezoid bodytrapezoid body lateral lemniscuslateral lemniscus 3rd Neuron: 3rd Neuron: Inferior Colliculus Inferior Colliculus brachium of inferior colliculusbrachium of inferior colliculus 4th Neuron: 4th Neuron: Medial Geniculate Nucleus (MG)Medial Geniculate Nucleus (MG) auditory radiationauditory radiation Termination: Termination: Primary Auditory Area (A I)Primary Auditory Area (A I) Brodmann area 31, 32Brodmann area 31, 32

Modality: Modality: Auditory Sensation (Hearing) Auditory Sensation (Hearing) Receptor: Receptor: Organ of Corti of Cochlear DuctOrgan of Corti of Cochlear Duct Cranial Nerve: VIIIcCranial Nerve: VIIIc

1st Neuron: 1st Neuron: Spiral GanglionSpiral Ganglion 2nd Neuron: 2nd Neuron: Cochlear Nucleus, Ventral & DorsalCochlear Nucleus, Ventral & Dorsal dorsal, intermediate and ventral acoustic striae dorsal, intermediate and ventral acoustic striae trapezoid bodytrapezoid body lateral lemniscuslateral lemniscus 3rd Neuron: 3rd Neuron: Inferior Colliculus Inferior Colliculus brachium of inferior colliculusbrachium of inferior colliculus 4th Neuron: 4th Neuron: Medial Geniculate Nucleus (MG)Medial Geniculate Nucleus (MG) auditory radiationauditory radiation Termination: Termination: Primary Auditory Area (A I)Primary Auditory Area (A I) Brodmann area 31, 32Brodmann area 31, 32

Auditory PathwayAuditory Pathway Auditory PathwayAuditory Pathway

Middle Ear - Sound AmplificationMiddle Ear - Sound AmplificationMiddle Ear - Sound AmplificationMiddle Ear - Sound Amplification

Inner Ear - Cochlear DuctInner Ear - Cochlear DuctInner Ear - Cochlear DuctInner Ear - Cochlear Duct

Organ of CortiOrgan of CortiOrgan of CortiOrgan of Corti

Organ of Corti - Inner and Outer Hair CellOrgan of Corti - Inner and Outer Hair CellOrgan of Corti - Inner and Outer Hair CellOrgan of Corti - Inner and Outer Hair Cell

Auditory PathwaysAuditory Pathways

A. spiral ganglionA. spiral ganglionB. dorsal and ventralB. dorsal and ventral cochlear nucleuscochlear nucleusC. inferior colliculusC. inferior colliculusD. medial geniculate nucleusD. medial geniculate nucleusE. Primary auditory areaE. Primary auditory areaF. superior olivary nucleusF. superior olivary nucleusG. nucleus of G. nucleus of lateral lemniscuslateral lemniscus

1. 1. acoustic striae &acoustic striae & trapezoid bodytrapezoid body2. 2. lateral lemniscuslateral lemniscus3. 3. brachium of inferiorbrachium of inferior colliculuscolliculus4. 4. auditory radiationauditory radiation5. 5. commissure ofcommissure of inferior colliculusinferior colliculusVIIIc. VIIIc. cochlear divisioncochlear division

Auditory PathwaysAuditory Pathways

A. spiral ganglionA. spiral ganglionB. dorsal and ventralB. dorsal and ventral cochlear nucleuscochlear nucleusC. inferior colliculusC. inferior colliculusD. medial geniculateD. medial geniculate nucleusnucleusE. Primary auditory areaE. Primary auditory areaF. superior olivary nucleusF. superior olivary nucleusG. nucleus of G. nucleus of lateral lemniscuslateral lemniscus

1. 1. acoustic striae &acoustic striae & trapezoid bodytrapezoid body2. 2. lateral lemniscuslateral lemniscus3. 3. brachium of inferiorbrachium of inferior colliculuscolliculus4. 4. auditory radiationauditory radiation5. 5. commissure ofcommissure of inferior colliculusinferior colliculusVIIIc. VIIIc. cochlear divisioncochlear division

Visual Visual

PathwayPathway

3 Tunics3 Tunics

Tunica FibrosaTunica Fibrosa: : cornea, scleracornea, scleraTunica VasculosaTunica Vasculosa: : choroid, ciliary body, irischoroid, ciliary body, irisTunica NervosaTunica Nervosa: : retinaretina

3 Chambers3 Chambers

Anterior Chamber Anterior Chamber Posterior ChamberPosterior ChamberVitreous BodyVitreous Body

EYEBALLEYEBALL

Modality: Modality: Vision Vision Receptor: Receptor: Photoreceptor Cell of RetinaPhotoreceptor Cell of Retina Cranial Nerve: II (Optic nerve)Cranial Nerve: II (Optic nerve)

1st Neuron:1st Neuron: Bipolar CellBipolar Cell 2nd Neuron: 2nd Neuron: Ganglion CellGanglion Cell optic nerveoptic nerve optic chiasmoptic chiasm optic tractoptic tract 3rd Neuron: 3rd Neuron: Lateral Geniculate Nucleus Lateral Geniculate Nucleus optic radiationoptic radiation Termination: Termination: Primary Visual Area (V I)Primary Visual Area (V I) Brodmann area 17Brodmann area 17

Modality: Modality: Vision Vision Receptor: Receptor: Photoreceptor Cell of RetinaPhotoreceptor Cell of Retina Cranial Nerve: II (Optic nerve)Cranial Nerve: II (Optic nerve)

1st Neuron:1st Neuron: Bipolar CellBipolar Cell 2nd Neuron: 2nd Neuron: Ganglion CellGanglion Cell optic nerveoptic nerve optic chiasmoptic chiasm optic tractoptic tract 3rd Neuron: 3rd Neuron: Lateral Geniculate Nucleus Lateral Geniculate Nucleus optic radiationoptic radiation Termination: Termination: Primary Visual Area (V I)Primary Visual Area (V I) Brodmann area 17Brodmann area 17

Visual PathwayVisual Pathway Visual PathwayVisual Pathway

1. Pigment Epithelium1. Pigment Epithelium - retinal detachment- retinal detachment

2. Neuronal Layer2. Neuronal Layer

(1) Photosensitive Cell Layer(1) Photosensitive Cell Layer

Rod Cell, Cone CellRod Cell, Cone Cell

(2) Bipolar Cell Layer(2) Bipolar Cell Layer Bipolar CellBipolar Cell Horizontal CellHorizontal Cell Amacrine CellAmacrine Cell

(3) Ganglion Cell Layer(3) Ganglion Cell Layer Ganglion CellGanglion Cell Optic Nerve (II)Optic Nerve (II)

RETINA RETINA - Pars Nervosa- Pars Nervosa

1. Optic nerve1. Optic nerve

2. optic chiasm2. optic chiasm

3. optic tract3. optic tract

4. lateral geniculate body4. lateral geniculate body

5. optic radiation5. optic radiation

6. visual cortex6. visual cortex

(striate cortex)(striate cortex)

7. Meyer’s loop7. Meyer’s loop

8. lateral ventricle8. lateral ventricle

Visual PathwayVisual Pathway

1. Optic nerve1. Optic nerve

2. Optic chiasm2. Optic chiasm

3. Optic tract3. Optic tract

4. Lateral geniculate 4. Lateral geniculate

bodybody

5. Optic radiation5. Optic radiation

6. Visual cortex6. Visual cortex

(Striate cortex)(Striate cortex)

Visual Visual PathwayPathwayVisual Visual

PathwayPathway

Clinical Features of Visual Pathway LesionClinical Features of Visual Pathway Lesion Clinical Features of Visual Pathway LesionClinical Features of Visual Pathway Lesion

1. optic nerve1. optic nerve

2. optic chiasm2. optic chiasm

3. optic tract3. optic tract

4. & 5. optic radiation4. & 5. optic radiation

A. unilateral blindnessA. unilateral blindness

B. bitemporal hemianopsiaB. bitemporal hemianopsia

C. left homonymousC. left homonymous hemianopsiahemianopsia

D. left inferior homony-D. left inferior homony- mous quadranopsiamous quadranopsia

E. left superior homony-E. left superior homony- mous quadranopsiamous quadranopsia

Olfactory Olfactory

PathwayPathway

Olfactory Olfactory

PathwayPathway

Sense of SmellSense of Smell

Modality: Modality: Olfaction Olfaction

Receptor: Receptor: Olfactory Cell of Olfactory EpitheliumOlfactory Cell of Olfactory Epithelium

Cranial Nerve: I (Olfactory Nerve)Cranial Nerve: I (Olfactory Nerve)

1st Neuron: 1st Neuron: Olfactory Bulb --- Mitral & Tufted CellOlfactory Bulb --- Mitral & Tufted Cell

olfactory tractolfactory tract

oolfactory striaelfactory striae

lateral & intermediate olfactory striaelateral & intermediate olfactory striae

Termination:Termination: Primary Olfactory Area (Rhinencephalon)Primary Olfactory Area (Rhinencephalon)

piriform lobe (prepiriform cortex, entorhinal cortex) piriform lobe (prepiriform cortex, entorhinal cortex)

corticomedial amygdala corticomedial amygdala

anterior perforated substance (olfactory tubercle)anterior perforated substance (olfactory tubercle)

Modality: Modality: Olfaction Olfaction

Receptor: Receptor: Olfactory Cell of Olfactory EpitheliumOlfactory Cell of Olfactory Epithelium

Cranial Nerve: I (Olfactory Nerve)Cranial Nerve: I (Olfactory Nerve)

1st Neuron: 1st Neuron: Olfactory Bulb --- Mitral & Tufted CellOlfactory Bulb --- Mitral & Tufted Cell

olfactory tractolfactory tract

oolfactory striaelfactory striae

lateral & intermediate olfactory striaelateral & intermediate olfactory striae

Termination:Termination: Primary Olfactory Area (Rhinencephalon)Primary Olfactory Area (Rhinencephalon)

piriform lobe (prepiriform cortex, entorhinal cortex) piriform lobe (prepiriform cortex, entorhinal cortex)

corticomedial amygdala corticomedial amygdala

anterior perforated substance (olfactory tubercle)anterior perforated substance (olfactory tubercle)

Olfactory PathwayOlfactory Pathway Olfactory PathwayOlfactory Pathway

Olfactory EpitheliumOlfactory Epithelium Olfactory ReceptorOlfactory Receptor Olfactory EpitheliumOlfactory Epithelium Olfactory ReceptorOlfactory Receptor

Olfactory epitheliumOlfactory epithelium Olfactory nerve (CN I) Olfactory nerve (CN I)

Olfactory Epithelium and Olfactory BulbOlfactory Epithelium and Olfactory Bulb Olfactory Epithelium and Olfactory BulbOlfactory Epithelium and Olfactory Bulb

OlfactoryOlfactory epitheliumepithelium

Olfactory BulbOlfactory Bulb

GlomerulusGlomerulus

Mitral cellMitral cell

Tufted cellTufted cell

periglomerular periglomerular

cellcell

Olfactory tractOlfactory tract

A. olfactory epitheliumA. olfactory epitheliumB. olfactory bulbB. olfactory bulbC. nucleus of diagonal bandC. nucleus of diagonal band of Brocaof BrocaD. periamygdaloid cortexD. periamygdaloid cortexE. cirticomedial amygdalaE. cirticomedial amygdalaF. entorhinal areaF. entorhinal areaG. septal nucleiG. septal nuclei

I. olfactory nerveI. olfactory nerve1. olfactory tract1. olfactory tract2. lateral olfactory stria2. lateral olfactory stria3. intermediate olfactory stria3. intermediate olfactory stria4. medial olfactory stria4. medial olfactory stria

Olfactory System - Olfactory PathwaysOlfactory System - Olfactory PathwaysOlfactory System - Olfactory PathwaysOlfactory System - Olfactory Pathways

Olfactory PathwaysOlfactory Pathways

I

A. olfactoryA. olfactory epitheliumepithelium

B. olfdactory bulbB. olfdactory bulbC. anterior C. anterior olfactoryolfactory nucleus &nucleus & olfactory olfactory tubercletubercle

D. periamygdaloidD. periamygdaloid areaarea

E. corticomedialE. corticomedial amygdalaamygdalaF. entorhinal areaF. entorhinal area

II. . olfactory nerveolfactory nerve 2. 2. lateral olfactory striaelateral olfactory striae1. 1. olfactory tract olfactory tract 3. 3. intermediate olfactory striaeintermediate olfactory striae

A. olfactory epitheliumA. olfactory epitheliumB. olfactory bulbB. olfactory bulbC. nucleus of diagonal bandC. nucleus of diagonal band of Brocaof BrocaD. periamygdaloid cortexD. periamygdaloid cortexE. cirticomedial amygdalaE. cirticomedial amygdalaF. entorhinal areaF. entorhinal areaG. mediodorsal thalamicG. mediodorsal thalamic nucleus (MD)nucleus (MD)

I. olfactory nerveI. olfactory nerve1. olfactory tract1. olfactory tract2. lateral olfactory stria2. lateral olfactory stria3. intermediate olfactory stria3. intermediate olfactory stria4. thalamocortical radiation4. thalamocortical radiation

Olfactory System Olfactory System - Connections of Primary Olfactory Cortex- Connections of Primary Olfactory CortexOlfactory System Olfactory System - Connections of Primary Olfactory Cortex- Connections of Primary Olfactory Cortex