Somato & Neruo 2 Flashcards
Dorsal root ganglion
Location of cell bodies (ncb) of first order sensory neurons
Support cells = satellite cells (sc)
Unmyelinated and myelinated axons (ma)
Spinal cord organization for sensory pathways
Dorsal column (funiculus)
2 divisions
Faciculus Gracilis - carries info abt caudal body & hindlimb
Faciculus cuneatus - carries info abt cranial body & forelimb
Grey matter organization
Rexed laminae 1-9
1 - pain & temp
2 - modulation
3 - touch
4 - touch
5 - pain
6 - position
7 - motor to viscera
8 - modulation
9 - motor to skeletal muscle
Dorsal Somatosensory pathways
Dorsal column system
Relays in for abt touch, position, vibration
First order neurons in dorsal SS pathway
Cell bodies in DORSAL root ganglion
Axon ascends in dorsal funiculus (dorsal columns
- hindlimb in Fas Gracilis (medial)
- forelimb in Fas cuneatus (lateral)
Synapses in nucleus Gracilis & cuneate nucleus in medulla
2nd order neuron Dorsal SS pathway
Cell body in brainstem nuclei
Axon crosses midline in medial lemniscus
Synapses in thalamus
3rd order neuron in dorsal SS pathway
Cell bodies in thalamus
Synapses in sensory cortex
Where 1st, 2nd, 3rd dorsal SS pathway synapse
1st - nucleus Gracilis & cuneate nucleus in medulla
2nd - thalamus
3rd - sensory cortex
Where orders cross in dorsal SS pathway
1st - axon ascends in dorsal funiculus
2nd - axon crosses at midline in medal lemniscus
3rd - cell bodies in thalamus
Lateral Spinothalamic tract
Relays information abt pain and temperature
Three neuron pathways
First neurons in lateral Spinothalamic tract
Cell body in dorsal root ganglion
Synapses in dorsal root of spinal cord
2nd neuron in lateral Spinothalamic tract
Cell body in dorsal horn of spinal cord
Axon crosses midline
Ascends in lateral funiculus
Synapses in thalamus
3rd neuron of lateral Spinothalamic tract
Cell body in thalamus
Synapses in sensory cortex
Where neurons synapse in lateral Spinothalamic tract
1st - dorsal horn of spinal cord
2nd - in thalamus
3rd - sensory cortex
Where axon crosses in lateral Spinothalamic tract
1st - cell body in dorsal root ganglion
2nd - crosses at midline
3rd - cell body in thalamus