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Nervous system
Chapter 19 the conductive pathway of nervous
system

• the sensory conductive pathway
• the motor conductive pathway
• the chemical pathway of nervous system

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The reflex path was referred to the conductive
path of preceding or descending without via
cerebral cortex.

• conscious
• nonconscious

• trunk?four limbs
• Head and facial part

• Conductive pathway of
• proprioceptive sense

• Trunk, four limbs
• Head and facial part

• The conductive pathway of sensation of pain and
  warm, thick touch sensation and ressure sense

Sensory(preceding)conductive pathway

• Visual conductive pathway and pupillary light
  reflex
• Auditory conductive pathway
• Conductive pathway of equilibratory sensation

• General visceral sence
• Special visceral sense

• Conductive pathway of visceral sense

• corticospinal tract
• corticonuclear tract

• pyramidal tract

Motor(descending)conductive pathway

• cortical substance-neostriatum-dorsal thalamus
  -circuit loop of cortex
• neostriatum-circuit of black substance
• pallidum-circuit loop of subthalamus
• cortex -bridge of varolius-cerebellum-circuit of
  cortex

• Extracorticospinal
• tract

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The sensory conductive pathway
conductive pathway of proprioceptive sense
the conductive pathway of conscious
proprioceptive sense of trunk and four limbs and
fine touch
peripheral process
?
Muscle, tendon, joint, skin
central process
spinal ganglia
Goll's column Burdach's fibers
spinal nerve
?
?
gracile nucleus Burdach's nucleus
bulbar lemniscus of opposite side
ventral posterolateral nucleus of dorsal thalamus
posterior limb of internal capsule

• The middle and superior part of posterior central
  gyrus
• The posterior part of paracentral lobule

all parts of brainstem
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(?)The conductive pathway of unconscious
proprioceptive sense in trunk and four limbs
The proprioceptor of muscle, tendon, and joint
the medial part of radix posterior
spinal cord
C8L2segment of thoracic nucleus
the lateral part of the 5th to 7th of
lumbosacral enlargement
funiculus lateralis medullae spinalis of homonymy
fiber of second class
posterior spinocerebellar tract
anterior spinocerebellar tract of opposite side
and ipsolateral
inferior cerebellar peduncle
superior cerebellar peduncle
cortex of palaeocerebellum
cortex of palaeocerebellum
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The superficial sensory pathway
The superficial sensory pathway of trunk and
limbs
?
?
central process
spinothalamic tract of opposite side
peripheral process
spinal cord?? ?? layer
skin
spinal ganglia
spinal nerve
ascends 1 to 2 segment
?
posterior limb of internal capsule
ventral posterolateral nucleus of dorsal thalamus
spinal lemniscus

• the middle and superior part of posterior central
  gyrus
• the posterior part of paracentral lobule

all parts of brain stem
(?) The superficial sensory pathway of head and
face
?
?
peripheral process
central process
trigeminal lemniscus
spinal nucleus of trigeminal nerve pontine
nucleus of trigeminal nerve
skin and mucosa
trigeminal ganglion
trigeminal nerves
?
posterior limb of internal capsule
the inferior part of posterior central gyrus
posteromedial nucleus of dorsal thalamusventral
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visual pathway and pupillary light reflex pathway
visual pathway
?
?
visual cone rod
optic nerve
nodal cell
bipolar neuron
posterior limb of internal capsule
chiasm opticum visual tract
external geniculate body
the two sides of calcarine fissure
optic radiation
?

• In the chiasm opticum, the fiber derived from
  retina of two eyes nasal side intersect, while
  the temple side ones dont intersect.

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The damaging of conductive pathway in different
position can induce different visual filed defect
?The injury of retina can induce visual field
defect, which is related to the position and
scope of injury ?The optic nerve injury of ones
side can induce absolute blindness of this eye
?The lesion of decussating fiber of chiasm
opticum can induce the half blindness in temple
side of binocular visual field ?the lesion of
non-decussating fiber of chiasm opticums lateral
part can induce the half blindness in nasal side
of binocular visual field ?the lesion of visual
tract in one side can induce homonymous
hemianopsia of opposite side.
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The pupillary light reflex pathway
The route of pupillary light reflex
direct light reflex indirect light reflex
retina?optic nerve?chiasm opticum? the visual
tract of two sides?brachium of superior
colliculus?pretectal area?
accessory nucleus of oculomotor nerve of two sides
?oculomotor nerve?
ciliary ganglion
?postganglionic fibre
?pupil sphincter muscle?the contraction of two
pupils
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The pupillary light reflex representation of
injury in different position
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The auditory pathway
organ of Corti ?bipolar cell (exchange
neuron) ?cochlear nerve ?ventral cochlear
nucleusdorsal and cochlear nucleus (exchange
neuron) ?trapezoid body of pons overlaps to the
opposite side ?lateral lemniscus ?the
dorsi-lateral part of tegmentum of
midbrain ?inferior colliculus (exchange neuron)
?brachium of inferior colliculus ?medial
geniculate body (exchange neuron) ?acoustic
radiation ?posterior limb of internal
capsule ?transverse temporal gyri of auditory
field in cerebral cortex
The auditory impulsion is conducing of two sides.
If one side path above lateral lemniscus is
damaged, the obvious symptom wouldnt happen. But
if the cochlear nerve, internal ear or middle ear
is damaged, auditory handicap will be induced.
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Motor pathways
Upper motor neurons Lower motor neurons final
common path
pyramidal system
cranial nerve motor nucleus
corticonuclear tract
pyramidal tract
somatic motor area of cerebral cortex pyramidal
cell
corticospinal tract
anterior horn of spinal cord motor neuron
pyramidal tract The giant pyramidal cell of
paracentral lobules anterior part and precentral
gyrus and the pyramidal cells of other type as
well as the axon of pyramidal cell which lie at
the frontal lobe and apical lobe constitute
pyramidal tract.
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corticospinal tract
posterior limb of internal capsule
?
the middle and superior part of anterior central
gyrus the anterior part of paracentral lobule
pyramidal cell
medulla oblongata
lateral corticospinal tract
midbrain, pons
anterior corticospinal tract
?
anterior horn motor neuron
spinal nerve
trunk muscle, limbs muscle
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corticonuclear tract
?
corticonuclear tract
pyramidal cell (inferior part of anterior central
gyrus)
knee of internal capsule

• nucleus of oculomotor nerve
• nucleus of trochlear nerve
• nucleus of abducent nerve
• motor nucleus of trigeminal nerve
• the superior part of nucleus of facial nerve
• nucleus ambiguus
• accessory nucleus

?

• extraocular muscles
• masseter muscle
• facial muscles(frontal muscle?orbicularis muscle)
• laryngeal muscle
• sternocleidomastoid
• trapezius

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• the inferior half of facial nucleus ? cheek
  muscle?orbicularis oris
• nucleus of hypoglossal nerve? lingual muscle

only recept the corticonuclear tract fiber of
opposite side

• supranuclear paralysis of facial nerve
• infranuclear paralysis of facial nerve
• supranuclear paralysis of hypoglossal nerve
• infranuclear paralysis of hypoglossal nerve

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The principal injury representation of upper
motor neurons and lower motor neurons
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extrapyramidal system
It is referred to the influence outside of
pyramidal system and all the conductive pathways
controlling body movement. Its structure is very
complex, which includes cerebral cortex, striate
body, dorsal thalamus, red nucleus, substantia
nigra,vestibular nucleus, cerebellum and so on.
The main functions of the extrapyramidal system
in man are to regulate the tonicity of the
muscles, coordinate the muscular activities,
maintain the normal body posture and produce
habitual and rhythmic movements.
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The extrapyramidal system concludes the following
four circuits
cortex-neostriatum-dorsal thalamus-cortex
neostriatum-substantia nigra
corticoponto-cerebellar-cortex globus
pallidus-subthalamus