Sensory Systems Flashcards
The two types of sensory neurons?
large and small
Large sensory neurons are part of the ….and small ones are part of the …
dorsal column medial lemniscal tract
anterior lateral spinothalamic system
3 Somatosensory neurons
first, second and third order
First order neurons are either …. or … neurons and their cell bodies are located outside CNS in ….
large or small
dorsal root ganglia
Second order neurons are located in the … or …
spinal cord (spinothalamic tract) or brain stem (dorsal column system)
Third order neurons are located in
thalamus
Dorsal column is responsible for …
2 point discrimination, vibration, proprioception and fine touch
First order neurons in DRG enter the spinal cord via dorsal root and ascend to form … and …
fasciculus gracilis and fasciculus cuneatus
Second order neurons in dorsal column tract cross the midline at the …. and …. nuclei for lower body and upper body respectively.
gracile and cuneate
Third order neurons in DRG axons project to 1 degree ipisilateral … cortex.
somatosensory
Spinothalamic Tracts (Anteriolateral) are responsible for…
pain, temperature and crude touch
The first order neurons in the DRG of spinothalamic tract enter spinal cord and ascend ….
ipsilaterally
The second order neurons in the dorsal horn of the spinothalamic tract cross to opposite side of the spinal cord to form….
anterior and lateral spinothalamic tract
Third order neurons in the …. of the spinothalamic tract project to somatosensory cerebral cortex on the ipsilateral side.
thalamus
Hyperalgesia
lowered threshold of peripheral nociceptors