4. Sensory System Flashcards
In the dorsal column pathway, the lower body maps to what portion of the tract?
Maps to the medial portion.
In the spinothalamic tract the lower body maps to which portion of the tract?
Maps to the lateral/superficial parts of the tract.
What modalities is the dorsal-column medial lemniscus pathway responsible for?
Light touch, joint position sense, vibration, two-point discrimination.
What modalities is the spinothalamic pathway responsible for?
Pain, temperature, crude touch.
In general, in the sensory system, where is the cell body of the primary sensory neurone located?
Cell body is in the dorsal root ganglia.
In general, in the sensory system, where is the cell body of the second order sensory neurone located?
Cell body is in the dorsal horn/medulla.
In general, in the sensory system, where is the cell body of the third order sensory neurone located?
Cell body is in the thalamus.
Isolated lesions of the dorsal-column medial lemniscus pathway in the spinal cord lead to signs where?
Ipsilateral signs below the lesion.
Isolated lesions of the spinothalamic pathway in the spinal cord lead to signs where?
Contralateral signs below the lesion.
What 3 signs does a complete cord hemisection causing destruction of a single cord segment, resulting from trauma or ischaemia, lead to?
Ipsilateral complete segmental anaesthesia affecting the dermatome at the level of the hemisection and below due to destruction of the dorsal root and dorsal horn.
Ipsilateral loss of dorsal column modalities below the lesion due to destruction of all white matter pathways.
Contralateral loss of spinothalamic modalities below the lesion due to destruction fo all white matter pathways.
How can rubbing a painful area alleviate pain?
Activates mechanoreceptors, impulse carried along A fibres to excite inhibitory enkephalinergic interneurones in the cord, inhibiting C fibres which carry pain.
