Ascending and descending tracts Flashcards
What are the two types of ascending tract?
Conscious and unconscious
What are the different conscious ascending tracts?
Dorsal column medial leminscal pathway and anterolateral system
What is the 1st order neurone of the DCML from the upper limb?
Sensation of the upper limb travels in the fasciculus cuneatus (lateral part of the dorsal column) and synapse in the nucleus cuneatus of the medulla.
What is the 1st order neurone of the DCML from the lower limb?
Sensation from the lower limb travels in the fasciculus gracilis (medial part of the dorsal column) and synapse in the nucleus gracalis of the medulla
What is the 2nd order neuron of the DCML?
Begins in the nucleus (either gracalis or cuneautus), ad then decusates in the medulla. This then travels in the contralateral medial lemiscus to the thalamus
What is the 3rd order neuron of the DCML?
Begins in the thalamus and then travels through the internal capsule to terminate at the sensory cortex
What sensations are carried in the DCML?
Sensory modalities of fine touch, vibration and proprioception from either the upper or lower limb
What sensations are carried in the anterior spinothalamic tract?
Sensory modalities of crude touch and pressure from both the upper and lower limb
What sensations are carried in the lateral spinothalamic tract?
Sensory modalities of pain and temperature from both the upper and lower limb
What is the first order neuron of the anterolateral system?
Arise from sensory receptors in the periphery of both the upper and lower limb. They enter the spinal cord, ascend 1-2 spinal levels, then synapse at teh tip of the dorsal horn
What is the second order neuron of the anterolateral system?
Begin at the tip of the dorsal horn, then decussate within the spinal cord, forming two seperate tracts which then travel together to the thalamus.
What is the third order neuron of the anterolateral system?
Travels from the thalamus to the ipsilateral primary sensory cortex of the brain through the internal capsule
What information does the posterior spinocerebellar tract carry?
Proprioceptive information from lower limbs to the ipsilateral cerebellum
What information does the cuneocerebellar tract carry?
Proprioceptive information from the upper limbs to the ipsilateral cerebellum
What information does the anterior spinocerebellar tract carry?
Proprioceptive information from the lower limbs, and decussate twice so travel to the ipsilateral cerebellum
What information does the rostral spinocerebellar tract carry?
Proprioceptive information from the upper limbs to the ipsilateral cerebellum
What are the 4 spinocerebellar tracts?
Posterior spinocerebellar tract
Cuneocerebellar tract
Anterior spinocerebellar tract
Rostral spinocerebellar tract
What information does the spinoreticular tract carry?
Deep/chronic pain