General Sensory Mechanisms Flashcards
What is summation?
Local potentials on dendrites are not strong enough to produce an action potential.
Spatial= signal strength increases via great number of fire fibers/discharging
All occupy on different space of the post synaptic neuron= Receptor field.
Nerve endings can actually under lap
What is Temporal Summation?
Increase in signal strength by increasing frequency of nerve impulse in each fiber.
What is a Neuronal Pool? And what are some characteristics?
Stimulators field
Area stimulated by each incoming nerve.
Input fibers lie on nearest neuron
Fewer terminals for each input neurons lie further away.
Discharge Zone= all output fibers stimulated by incoming fiber
Facilitated/inhibition zone=Primed but not excited, my be inhibitory too
What are the two morphological neuronal pathways.
Diverging and Converging pathways.
Diverging is amplification
What are the General Characteristics neural receptors?
Differential Sensitivity= receptor is highly sensitive to a type of stimulus and is non responsive to other.
Modality=function or principal type of sensation. Examples include Semantic Motor, Visceral Motor.
Labeled line principle= specificity of nerves for transmitting one modality
Adaption= partially or completely to any stimulus
How do we develop AP from local potential receptors?
Deformation serves to bring the receptor depolarize the receptor potential and lead to and AP
What are the Tonic Receptors characteristics?
Slow adapting
Detection of continuous stimulus strength
Transmit as long as stimulus is present
What are the Phasic Receptor Characteristics?
Rapidly adapt
Not continuous
Stimulated when stimulus strength changes
Transmit info regarding rate of change
What are the nerve fiber types?
Type A and Type C
Describe Type A fiber types?
Alph, Beta, Gamma, Delta
Large/medium, myelinated
Describe Type C fiber types?
Small
Unmyelinated
More 50% of PNS and all postganglionic ANS
What are the Nerve Fiber Groups?
Ia=Spindles
Ib=Gogli
II=Cutaneous tactile receptors
III=Temp, crude touch, and pricking pain
IV=Carry pain, itch, temp, crude touch
What is a Reverberatory Circuit?
Oscillatory circuit
Cause positive feedback may discharge repetitively for long periods of time.
May also inhibit through a collateral fiber to an interneuron.
Will release an inhibitory neurotransmitter
