Download Ascending (Sensory) Pathways Pathway/Tract Sensation First Order

Ascending (Sensory) Pathways
Pathway/Tract
Sensation
First Order
Neuron
Second Order
Neuron
Third Order
Neuron
POSTERIOR COLUMN PATHWAY
Fasciculus
gracilis
Fasciculus
cuneatus
SPINOTHALAMIC PATHWAY
Lateral
spinothalamic
tracts
Anterior
spinothalamic
tracts
SPINOCEREBELLAR PATHWAY
Posterior
spinothalamic
tract
Anterior
spinothalamic
tract
Final
Destination
Site of
Crossover
(Decussation)
Descending (Motor) Pathways
Tract
Location of Upper
Motor Neurons
Destination
CORTICOSPINAL PATHWAY
Corticobulbar tracts
Lateral corticospinal
tracts
Anterior
corticospinal tracts
MEDIAL PATHWAY
Vestibulospinal
tracts
Tectospinal tracts
Reticulospinal tracts
LATERAL PATHWAY
Rubrospinal tract
Site of Crossover
Action
Ascending (Sensory) Pathways
Pathway/Tract
Sensation
First Order
Neuron
Second Order
Neuron
Third Order
Neuron
Final
Destination
Site of
Crossover
(Decussation)
Fasciculus gracilis
Proprioception and
fine touch,
vibration from
inferior half of
body
Proprioception and
fine touch,
vibration from
superior half of
body
Dorsal root ganglia
of inferior half of
body
Nucleus gracilis of
medulla oblongata
Ventral nuclei of
thalamus
Primary sensory
cortex on side
opposite stimulus
Axons of 2nd order
neuron before
entering medial
meniscus
Dorsal root ganglia
of superior half of
body
Nucleus gracilis of
medulla oblongata
Ventral nuclei of
thalamus
Primary sensory
cortex on side
opposite stimulus
Axons of 2nd order
neuron before
entering medial
meniscus
POSTERIOR COLUMN PATHWAY
Fasciculus
cuneatus
SPINOTHALAMIC PATHWAY
Lateral
spinothalamic
tracts
Anterior
spinothalamic
tracts
Pain and
temperature
Dorsal root ganglia
Interneurons in
posterior gray horn
Ventral nuclei of
thalamus
Primary sensory
cortex on side
opposite stimulus
Axons of 2nd order
neurons at level of
entry
Crude touch and
pressure
Dorsal root ganglia
Interneurons in
posterior gray horn
Ventral nuclei of
thalamus
Primary sensory
cortex on side
opposite stimulus
Axons of 2nd order
neurons at level of
entry
SPINOCEREBELLAR PATHWAY
Posterior
spinothalamic
tract
Anterior
spinothalamic
tract
Proprioception
Dorsal root ganglia
Interneurons in
posterior gray horn
Not applicable
Cerebellar cortex
on side of stimulus
Not applicable
Proprioception
Dorsal root ganglia
Interneurons in
same spinal
section
Not applicable
Cerebellar cortex
on side and
opposite side of
stimulus
Axons of most 2nd
order neurons
before entering
tract, some recross at cerebellum
Descending (Motor) Pathways
Tract
Location of Upper
Motor Neurons
Destination
Site of Crossover
Action
CORTICOSPINAL PATHWAY
Corticobulbar tracts
Primary motor cortex
Lateral corticospinal
tracts
Primary motor cortex
Anterior
corticospinal tracts
Primary motor cortex
Lower motor neurons of
cranial nerve nuclei in brain
stem
Lower motor neurons of
anterior gray horns of spinal
cord
Lower motor neurons of
anterior gray horns of spinal
cord
Brain stem
Conscious motor control of
skeletal muscles
Pyramids of medulla
oblongata
Conscious motor control of
skeletal muscles
Level of lower motor
neuron
Conscious motor control of
skeletal muscles
None
Subconscious regulation of
balance and muscle tone
Brainstem
Subconscious regulation of
eye, head, neck, and upper
limb position
Subconscious regulation of
reflex activity
MEDIAL PATHWAY
Vestibulospinal
tracts
Tectospinal tracts
Reticulospinal tracts
Vestibular nuclei
Tectum
Reticular formation
Lower motor neurons of
anterior gray horns of spinal
cord
Lower motor neurons of
anterior gray horns of
cervical spinal cord
Lower motor neurons of
anterior gray horns of spinal
cord
None
LATERAL PATHWAY
Rubrospinal tract
Red nuclei of
mesencephalon
Lower motor neurons of
anterior gray horns of spinal
cord
Brainstem
Subconscious regulation of
upper limb muscle tone and
development