5 Ascending Sensory Systems

Question 1

Ascending sensory pathway. Two point discrimination and conscious proprioception, vibratory sense. Synapses in medulla then decussates forming this tract. Relays in lateral thalamus, terminates in postcentral gyrus

Answer 1

Posterior column- medial lemniscus pathway

Question 2

Ascending pathway. One of multiple pathways that convey pain and temp; involved in awareness and localization of painful stimuli; ultimately ends in VPL of thalamus and some nearby thalami nuclei.

Answer 2

Spinothalamic tract (STT)/ Anterolateral pathway

Question 3

Damage to the STT/Anterolateral pathway causes loss of _____, _____, _____ sensations. Bowel/bladder pressure, sexual sensations ascend ______ so unilateral injury does not leave a deficit.

Answer 3

Pain, temp, itch/tickle

Bilaterally

Question 4

Destroy spinothalamic tract to produce contralateral analgesia in patents with intractable pain. Cut lateral funiculars from dentate ligament to ventral root rostral to highest dermatomal pain level.

Answer 4

Cordotomy

Question 5

Ascending pathway. Convey proprioceptive info. Collaterals from posterior columns convey tactile, pressure and proprioceptive info synapse in Clarke’s nucleus. Axons ascend ipsilateral lateral funiculars forming PSCT on cord surface. Fibers enter cerebellum via inferior cerebellar peduncle. Ipsilateral leg proprioception.

Answer 5

Posterior Spinocerbellar Tract (PSCT)

Question 6

Ascending path. Most spinocerrebellar-like fibers that enter in cervical and upper thoracic segments (arm) do not project to Clarke’s nucleus. Arm afferent ascend in fasciculus cuneatus to lateral cuneate nucleus in medulla. Axons from LCN collect and form this tract, enter inferior cerebellar peduncle to synapse in vermis.

Answer 6

Cuneocerebellar tract

Question 7

Ascending path. Conveys more complex info (attempted movement) to cerebellum. Origin: lateral surface of anterior horn at lumbar level. Primarily concerned with leg but different from PSCT. Crosses midline twice, so ultimately ipsilateral to source

Answer 7

Anterior Spinocerebellar Tract (ASCT)

Question 8

STUDY BOOKMARKED SLIDES

Answer 8

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