Flashcards in Lecture: Ascending Sensory Pathways I Deck (17):
What is the Spinothalamic pathway responsible for?
What is the dorsal column pathway responsible for?
joint position (proprioception)
Describe the type of fibres in the spinothalamic pathway
Poorly myelinated or unmyelinated
Describe the type of fibres in the dorsal column pathway
Are the dorsal column pathway and spinothalamic pathway ipsilateral, or contralateral?
Dorsal Column - Ipsilateral, then crosses at closed medulla
Spinothalamic - contralateral, crosses at point of entry
To which part of the thalamus does the information carried in these pathways project?
Where does the primary neuron synapse?
With the secondary neuron in the dorsal grey horn on the same side that it enters.
Just at different levels depending on STT or DCP
To which part of the thalamus do sensory fibres from the face ascend?
Describe briefly how the post-central gyrus is somatotopically mapped
From lateral to medial:
Pharynx-tongue-mouth-face (ascending)-thumb-hand-along arm-trunk-down body-legs-toes-genitals
What is the spinothalamic pathway renamed as it enters the medulla?
The Spinal Lemniscus
How are the dorsal column pathways organised?
Into two pathways, the Gracile Fasciculus and the Cuneate Fasciculus
Terminate at the Gracile and Cuneate Tubercles respectively
Describe the Gracile Fasciculus
More medial to midline
runs whole length of the spinal cord
receives information from lower limbs and trunk
Describe the Cuneate Fascicle
exist above T6 only
receives info from the arms
Where do the primary neurons of the Dorsal Column Pathway synapse?
In the gracile/cuneate nuclei, located in the tubercles on the dorsal brainstem
Describe the course of the secondary neurons in the DCP
Cross at the closed medulla
Referred to as Internal Arcuate Fibres
Pass to the Medial Lemniscus where they ascend to VPL thalamus
is the medial lemniscus somatotopically mapped?
Yes, divisions for Arm, Trunk and Leg