ASCENDING TRACT1.pptx

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. FIRST ORDER NEURON SECOND ORDER NEURON THIRD ORDER NEURON

6. Ascending Tracts

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

8. Tracts of Spinal Cord

9. Lateral Spinothalamic tract Decussation Lateral spinothalamic tract Destination Posterior central gyrus 3rd Order Neuron Ventral posterolateral nucleus of Thalamus Pathways Lateral spinothalamic , Spinal lemniscus ? S pinotectal 2nd Order Neuron ? Substantia gelatinosa / Rexed III-VII 1st Order Neuron Posterior root ganglion Receptor Free nerve endings

10. 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 .

11. 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

12. 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

13. 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

14. Lesion of Spinal Cord

15. Injury to ascending tract within the spinal cord

16. 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.

17. 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.

18. Posterior Cord Syndrome

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

20. 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-

21. 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

22. 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-.

23. Thank You