somatosensory function Flashcards
central sensory structures: identify the location of sensory cortex and the parietal association cortex, and explain the somatotropic organisation
in the central pathway, where is somatotropic organisation maintained
throughout entire pathway from dermatomes to cortex via dorsal columns/medial lemniscus
where does decussation of pathway for information coming from body and head occur
in the brainstem
what enhances the difference between adjacent inputs
lateral inhibition
when do touch and proprioceptive stimuli only become a conscious, localised, perceived sensation
when they reach the cortex
where is primary somatosensory cortex (SI)
anterior (rostral) to posterior parietal cortex; postcentral gyrus (posterior to central sulcus)
SI: what is the body map distorted according to
relative density of inputs from different parts of the body
how does response of neurones in SI vary
some respond to stimulus properties (e.g. pressure, vibration), some respond to abstract properties (e.g. movement, object shape)
where is secondary somatosensory cortex (SII)
below (ventral to) SI in centre of brain near temporal lobe
what does SII receive and where from
intracortical projections from SI
what is the function of the posterior parietal cortex, caudal to SI
interpretation of spatial relationships
