NEURO LEC 9 TRACTS Flashcards
sensory information vs. sensation
sensory information: stimulus that causes nerve impulses
sensation: awareness of stimuli
role of the thalamus and cortex in somatosensation
the thalamus relays to the somatosensory cortex which detects sensation, leading to perception
motor homunculus
medial to lateral: legs, head, arms, face
sensory homunculus
legs, trunk, arm, face
projection neurons
long axons that transmit sensory info over long distances (ex: SC to brain)
A first order neuron starts at the ____ and goes to the _____
Periphery
Brainstem/SC
A second order neuron starts at the ____ and goes to the _____
SC/Brainstem
Thalamus
A Third order neuron starts at the ____ and goes to the _____
Thalamus
Somatosensory Cortex
Where is the cell body of a 1st order neuron found?
Dorsal root ganglion
How are spinal tracts named?
Origin and end of their 2nd order neuron
Concious vs Divergent pathways
Concious- Discriminitive information (example: pin point sharp pain)
Divergent- Not discriminitive (Example: achey pain in the entire limb)
Nonconcious relay pathways provide ______ information to cerebellum
nonconcious proprioceptive information
ex: coordination, balance, and posture adjustment
The dorsal tract is considered (Concious and/or divergent)
Whereas the Anteriolateral pathway is (Concious and/or divergent)
Dorsal- Concious
A/L - Both
For crude awareness, sensory info must get to ________
For concious awareness it must get to the _________
Thalamus
Somatosensory cortex
What are the 2 concious relay pathways
Dorsal columns and Anteriolateral columns
Senses of the dorsal column?
Conscious Proprioception, light touch, stereognosis, two point discrimination
remember its conscious so it will be detailed
Senses of the anterolateral column?
Discriminitive pain, temperature, crude touch
DCML 1st order neuron
peripheral receptors to medulla (gracile/cuneate nucleus)
DCML 2nd order neuron
medulla (gracile/cuneate nucleus) to VPL of thalamus
DCML 3rd order neuron
VPL of thalamus to contralateral primary somatosensory cortex
The dorsal column crosses sides in the ________
Internal arcuate fibers in the Medulla
The dorsal column travels from the medulla to the thalamus as Nucleus Gracilis OR Cuneatus
Gracilis is for ____ wherewas Cuneatus is for _________
Gracilis - lower body sensation
Cuneatus - upper body sensation
Where is the secondary somatosensory gyrus and what info does it process?
just behind the primary one
process more complex sensory information - stereognosis, sensory memories (past tactile experiences)
what are the two “types” of the spinothalamic tract?
anterolateral spinothalamic tract
paleospinothalamic tract