Neuro - Sensorimotor Pathways Flashcards
Where does the medial lemniscus pathway decussate?
In the medulla oblongata, with the internal arcuate fibres
Describe the path of fine touch and proprioception sensation from the upper limb
Receptors
Cell bodies are in the dorsal root ganglion
Travel up spinal cord in cuneate fasiculus of the dorsal column
Synapse in cuneate nucleus of medulla oblongata
Decussate in medulla oblongata, in internal arcuate fibres
Synapse in thalamus, in ventral posterolateral nucleus
Fibres go on to the post central gyrus
Describe the path of fine touch and proprioception sensation from the lower limb
Receptors
Cell bodies are in the dorsal root ganglion
Travel up spinal cord in gracile fasiculus of the dorsal column
Synapse in gracile nucleus of medulla oblongata
Decussate in medulla oblongata, in internal arcuate fibres
Synapse in thalamus, in ventral posterolateral nucleus
Fibres go on to the post central gyrus
Which pathway carries fine touch and proprioception from the limbs?
The medial lemniscus pathway
Which pathway carries limb motor?
The lateral corticospinal tract
Which spinal tract carries pain and temperature?
The lateral spinothalamic
Which spinal tract carries crude touch?
The anterior spinothalamic tract
Which spinal tract carries axial motor?
The ventral corticospinal
What components make up the dorsal column?
The gracile and cuneate fasiculi
Which pathway carries limb motor?
The lateral corticospinal tract
Which spinal tract carries pain and temperature?
The lateral spinothalamic
Which spinal tract carries crude touch?
The anterior spinothalamic tract
Which spinal tract carries axial motor?
The ventral corticospinal
What components make up the dorsal column?
The gracile and cuneate fasiculi
Where does the pathway carrying axial motor decussate?
In the anterior white commissure of the vertebral level it will innervate
Where does the pathway carrying limb motor decussate?
In the medulla oblongata
Describe the corticospinal pathway
Begins in the Pre-central gyrus, in the Primary motor cortex
Fibres travel through the internal capsule
In the medulla, 70-90% of the fibres decussate and travel down the lateral corticospinal tract - these supply the limbs.
The rest of the fibres descend through the anterior corticospinal tract until their vertebral level, where they decussate.
Both then synapse in the ventral horn before exiting the spinal cord.
Describe the path of the spinothalamic pathway
Receptor
Sensory neurone
Dorsal root ganglion
Enters the spinal cord and travels up or down 1 or 2 vertebral levels within Lissauer’s fasiculus before synapsing on the dorsal horn
Decussates immediately in the anterior white commissure then travels up in the spinothalamic tract
Synapse in the thalamus before carrying on to the post-central gyrus
