Perception Flashcards
What are the three main levels of neural integration in the somatosensory system?
Receptor level- sensory receptors
Circuit level- Ascending pathways
Perceptual level- Neuronal circuits in the cerebral cortex
Where does input into the somatosensory system come from?
Exteroceptors
Proprioceptors
Interceptors
How many chains of neurons conduct sensory impulses upward to the cerebral sensory cortices?
Three chains of neurons
Describe first-order neurons
Cell bodies residing in the dorsal root/cranial ganglia
Conduct impulses from skin to spinal cord/brain stem
Describe second-order neurons
Soma reside in the dorsal horn of the spinal cord/medullary nuclei
Axons cross the midline (decussate) to transmit impulses to the thalamus or cerebellum
Describe third-order neurons
Located in the thalamus and conduct impulses to the somatosensory cortex of the cerebrum
What features are common to virtually all sensory systems?
Vision
Audition
Tase
The bipolar cell is the primary sensory neuron for….
Vision and audition
What is the second order neuron for vision?
The ganglion cell whose axon crosses the midline in the optic chasm to innervate the thalamus and then on to the visual cortex
What is the second order neuron for audition?
The superior Oliveri nucleus in the brain stem
The axons of which cross the midline and project to the thalamus and then on to the auditory cerebral cortec
What is the role of the taste buds of the tongue?
They activate sensory endings of the geniculate ganglia gustatory neurons
What innervated the second order neurons of the solitary nucleus in the medulla, allowing it to cross the midline and project to the thalamus, then gustatory cortex?
geniculate ganglia gustatory neurons
What is decussation?
A crossing within the CNS
What is a chiasma?
A crossing in the PNS
Where does the pain component for the face end?What is it similar to?
Spinal nucleus of the trigeminal
Spinal cord gray matter
