week 9 - somatosensation Flashcards
What are the types of sensory receptors?
- nociceptors
- thermo-receptors
- mechanoreceptors
- chemoreceptors
- proprioceptors
- baroreceptors
nociceptors
detect pain (overlap with mechanical, thermal, and chemical)
thermoreceptors
- detect temperature
- cold/warm receptors
mechanoreceptors
- constructed to detect membrane distortion
- 3 different types (tactile, discriminative, and crude)
efferent pathways
conduct motor commands
tactile receptors (mechanoreceptors)
detect touch, pressure, and vibrations
What are the two main somatosensory pathways?
- dorsal column pathway
- spinothalamic tract
dorsal column pathway
primary carries sensations of touch, vibrations, and propriception
spinothalamic tract/anterolateral pathway
carries information regarding temperature and pain
chemoreceptors
- detect concentration of specific chemicals/compounds
- play a role in maintaining homeostasis
proprioceptors
allow us to detect positions of joint and muscles
baroreceptors
detect pressure changes deep in our body
Describe how receptive fields work and how stimuli in overlapping receptive fields are perceived.
- skin contains receptor fields, and the area they cover all vary in size.
- smaller receptive fields will be closer together, which makes it easier to detect change and localize a stimulus.
- larger receptive fields do not detect changes as quick, which is why it is harder to localize a stimulus
tonic receptors
- always active
- detect the level of stimulation
- monitor background levels
phasic receptors
- detect change in stimulation
- become active for a short time whenever change occurs
- monitors intensity and rate of change of stimulus
afferent pathways (sensations)
- responsible for sensing information at the skin/muscle
- detected by sensory receptors
describe how the somatosensory homunculus affects perception of bodily sensation
- representation of the human body within the somatosensory cortex of the brain
- cortical map illustrates the relative proportions of different body parts, with larger areas dedicated to regions that are more sensitive
- more cortical processing to hands and lips -> better sensory discrimination