The ascending tracts carry sensory information from the body, like pain, for example, up the spinal cord to the brain. Descending tracts carry motor information, like instructions to move the arm, from the brain down the spinal cord to the body.

1. Ascending Tracts of Spinal Cord

2. Contents
• General Introduction
• Ascending Tracts
• Clinical
• MCQ’s

3. General features
Anterior white column (or
funiculus)
Lateral white column (or
funiculi)
Posterior white column (or
funiculus)
Anterior white commissure.

4. Tracts

5. 1. FIRST ORDER NEURON
2. SECOND ORDER NEURON
3. THIRD ORDER NEURON

6. Ascending Tracts

8. Anterior Spinocerebellar Tract Unconscious
Proprioception
Gross
movements
Posterior Spinocerebellar Tract Unconscious
Proprioception
Fine
movements

9. Tracts of Spinal Cord

10. Lateral Spinothalamic tract
Lateral spinothalamic tract
Destination Posterior central gyrus
3rd Order Neuron Ventral
posterolateral
nucleus of
Thalamus
Pathways Lateral spinothalamic,
Spinal lemniscus? Spinotectal
2nd Order Neuron ?
Subst
antia
gelati
nosa
/
Rexe
d III-
VII
1st Order Neuron Posterior root ganglion
Receptor Free nerve endings

15. Posterolateral tract of Lissauer
• 1st order neuron enters posterior horn & divides into
ascending and descending branches that travel for 1-
2 segments, then terminate synapsing with 2nd
order neurons in substantia gelatinosa.

16. Dorsal Columns
Destination Posterior central gyrus
3rd Order Neuron Ventral posterolateral
nucleus of Thalamus
2nd Order Neuron Nuclei gracilis and cuneatus in
medulla oblagata
Few IV-VI
Pathways Ipsilateral Fasciculi gracilis &
cuneatus
Medial lemniscus
1st Order Neuron Posterior root ganglion
Receptors
Meissner's corpuscles,
Pacinian corpuscles, muscle
spindles & tendon organs

18. • Axons of the second-order neurons
• Called Internal arcuate fibres cross
median plane.
• Decussate with corresponding fibres
of opposite side in medulla as
sensory Decussation
• Fibres ascend as a single compact
bundle called medial lemniscus
through the brainstem.
FC FG

25. Other Ascending Tracts
Spinotectal tract Spinovisula reflexes
Movement of eyes & head in response to
source of the stimulation
Spinoreticular tract Reticular formation,
Level of consciousness
Pain perception
Spino-olivary tract Convey cutaneous and proprioceptive
Information to cerbellum
Spino-cervicothalamic Hair movement, pinch, pressure, thermal
stimuli, noxious stimuli

26. Lesion of Spinal Cord

27. Injury to ascending tract within the spinal cord

28. Anterior Spinothalamic Tract
• Contralateral loss of light touch sensations
below the level of the lesion
• Contralateral loss of pressure sensations
below the level of the lesion
• The patient will
• not feel the light touch of a piece of cotton
placed against the skin and cant feel pressure
from a blunt object placed against the skin.

30. Tabes Dorsalis
– is caused by syphilis.
– a selective destruction of nerve fibres at the point of
entrance of the posterior root into the spinal cord,
• specially in the lower thoracic and lumbosacral
regions.
• Results in loss of some sensation & hypersensitivity
of others.

31. Posterior Cord Syndrome

35. MCQ-1
• Ascending tract conduct afferent information
through exteroceptive and proprioceptive groups.
What type of afferent information were carried
through lateral spinothalamic tract .
a) Pain and temperature
b) Crude touch & pressure
c) Joint sense
d) Vibratory sense
a) Pain and temperature
Snell clinical neuroanatomy 7th edition , pg number 144

36. • Posterior spinal artery supply the posterior funiculus
or the area in between the posterior horn.
Interruption of posterior spinal artery cause
condition posterior cord syndrome . What type of
sensation carried through posterior funinculus.
• Pain & temperature
• Crude touch & pressure
• Fine touch & two point discrimination
• No sensory tract
Fine touch & two point discrimination
Lindeire S, Hauser JM. Anatomy, Back, Artery Of Adamkiewicz. [Updated 2021 Aug 1].
In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-

37. • A pt come to an OPD with a characteristic feature of
loss of joint and vibration sense, after he falls on his
back 3-4 days ago. An MRI image shows
anterolistheis at L1-L2 level. Which suggest the
compression of dorsal column of spinal cord. Name
the tract which is involved in carrying joint and
vibration sense.
• Fasciculus gracilis
• Fasciculus cuneatus
• Lateral spinothalamic tract
• Spinocerebellar tract
Fasiculus gracilis
Snell clinical neuroanatomy 7th edition , pg number 149

38. REFERENCES
• Snell clinical neuroanatomy 7th edition
• Khan YS, Lui F. Neuroanatomy, Spinal Cord. [Updated
2021 Jul 31]. In: StatPearls [Internet]. Treasure Island
(FL): StatPearls Publishing; 2022 Jan-.

39. Thank You