Somatosensory System Flashcards
what are all sensations processed as in the nervous system?
electrical signals (action potentials)
true or false – receptor cells are not always neurons
true
how is the somatosensory system organized?
hierarchically
what is ipsilateral projection?
sensed and processed on the same-side
what is contralateral projection?
sensed and processed on the opposite side
what is proprioception?
perception of body position
what is nociception?
perception of pain
what is pruiception?
perception of itch
which major type of skin mechanoreceptors processes light touch?
merkel’s disk
which major type of skin mechanoreceptors processes touch and slow vibrations?
meissner’s corpscles
which major type of skin mechanoreceptors processes stretch, pressure, and warmth?
ruffini endings
which major type of skin mechanoreceptors processes brief and rapid vibrations and deep pressure?
pacinian corpscles
what is labeled line signal processing?
different qualities of touch are detected by different receptors and have different neural pathways to the brain.
through which region can a sensory receptor detect stimuli to relay the info to the brain?
receptive field
what will happen if primary neurons converge?
one large receptive field will be created and secondary neurons cannot be discriminated
what will happen if primary neurons don’t converge?
small receptor fields will be created and secondary neurons can be discriminated
where are neural cell bodies located?
in the dorsal root ganglion along the spinal cord
how is information processed through the spinal cord?
- info ascends ipsilaterally in the dorsal columns to the medulla (brainstem).
- info crosses the midline.
- travels to the somatosensory cortex through the thalamus.
what are dermatomes?
areas of skin that are connected to a specific nerve on the spine
where is touch information transmitted to?
ventral posterolateral nucleus (VPL) then to primary somatosensory cortex
what is the somatosensory homunculus?
a body map that depicts the amount and location of where each part of the body is processed.
which body parts have the largest representation in the somatosensory homunculus?
hands, face, and tongue
what is the modulation of representation?
the size of somatosensory representation changes with use.
