Numbness Flashcards
loss of sensation
Numbness
Numbness is caused by damage to what structure?
Ascending tracts
What are the ascending tracts?
Spinothalamic
Dorsal Column Medial Lemniscus (DCML)
Spinocerebellar
Receives pain, temperature impulses from the dorsal
horn (from extremities)
Spinothalamic tract
Types of spinothalamic tract
Anterior and Lateral
Primary sensory area
Area 3, 1, 2
Begins at temperature and pain receptors
Neuron 1 Spinothalamic tract
Axon and cell body of neuron 1
Axon: Peripheral nn
Cell body: DRG
Where does neuron 1 enter?
Dorsal horn of the spinal cord
Pain pathway
LST
Where does neuron 2 start?
Dorsal column
Where does the pain sensation go to from neuron 2?
VPL
Where does temperature sensation go from neuron 2?
Nucleus Proprius Dorsalis
A lesion that may lead to loss of pain and temperature sense.
Thalamic lesions
Where does neuron side tracks to?
Reticular formation
Where does neuron 3 of the Spinothalamic tract begin?
Ventral Posterolateral Nucleus of the Thalamus (VPL)
Where does sensation go from the VPL?
Primary sensory area (3, 1, 2)
Posterior columns
Dorsal Column Medial Leminiscus
What sensations does DCML receive?
Conscious proprioception, Vibratory sense, 2-pt discrimination, Tactile sense
Transmits the sensations received by the DCML from the upper body
Fasciculus Cuneatus
Transmits the sensations received by the DCML from the lower body
Nucleus Gracilis
Pathway for sensation reception
Receptors
Peripheral nn
Dorsal column of the SC
Decussates to go up to the brain stem
VPL
Thalamus
Primary sensory area
Responsible for unconscious sensation
Spinocerebellar tract