??? Flashcards
Receptive fields are defined as…
An area surrounding the receptor that when stimulated excites or inhibs the firing of a particular cell
What areas of the body have the smallest receptive fields AND the largest number of receptive fields per area?
- ) Tips of the fingers
- ) Tongue
What are the most sensitive parts of the body?
- ) Tips of the Fingers
- ) Tounge
As you move ___direction___ receptive field size increases or decreases?
As you move proximal, receptive field size increase
As you move \_direction_ density of receptors increase or decrease?
As you move proximal density of receptors decrease
As you move proximally does sensitivity decrease of increase?
Decrease
Dermatomes are defined as…
The area of the body surface contributing sensory input to one dorsal root
What serves to sharpen peak of activity within the brain?
Lateral Inhibition
Where does lateral inhibition occur first?
in the dorsal column nuclei and then at subsequent synapses in the CNS
Lateral inhibition is also present in what other system?
Visual system
Lateral inhibition serves to enhance distinction between what?
Two stimuli
Lateral inhibition aids in recognition of what?
pattern and contour
Excitatory discharge is greatest where? and inhibitory where?
Greatest at the center of a receptive field and inhibitory at the periphery
Lateral inhibition is defined as what?
The capacity of an excited neuron to reduce the activity of its neighbors
Lateral inhibition disables the spreading of what?
Action potentials from excited neurons to neighboring neurons in the lateral direction.
Areas with the largest receptor density will have the largest what?
Cortical receptive field
Orderly mapping of sensations from body surface onto CNS areas is as follows:
- ) Dorsal Column Nuclei
- ) Thalamus
- ) Somatosensory cortex (Sensory homunculus)
In the sensory cortex there are cells that respond to 3 aspects of the stimuls. What are those 3 aspects?
- ) Specific orientation
- ) Movement
- ) Shape of stimulus
