Ascending Spinal Pathways Flashcards
anatomical types of receptors
free nerve endings - pain
encapsulated - touch, mechanical
special neural receptor cells - special/chemical senses
functional types of receptors
mechanoreceptors nociceptors photoreceptors chemoreceptors thermoreceptors
adequate stimulus
most appropriate stimulus that will allow receptor to pass current
modality
the sense it carries
ex/ stimulus = light
modality = vision
receptor potential
proportional to strength of stimulus
-graded potential
at threshold - primary afferent produces action potential
pre-cenral gyrus
primary motor cortex
post-central gyrus
primary somatosensory cortex
brodmans areas post central gyrus?
3, 1, 2
somatosensory
brodmans area for pre-central gyrus?
4
motor
targets for somatosensation
reflex arc reticular formation hypothlamus > limbic system thalamus > cerebral cortex cerebellum
**divergence of neurosystem
labeled line code
if you stimulate this tract
-modality of this tract results in certain sensation being felt
codes modality
population code
as intensity increases
number of receptors activated increased
frequency code
as intensity increases - rate of APs increases
receptor field
part of environment to which neuron responds
resolution
ability to distinguish between 2 separate stimulus
low density - large receptive field - less resolution
-few number of neurons in cortex
high density - small receptive field - more resolution
-larger number of neurons in cortex
large receptive field
lower density
lower resolution
fewer number of neurons in cortex
