Sensory Neurons Flashcards
What is transduction?
Conversion of one energy form to another - sensory cells do this
What do accessory structures do?
Help capture, filter and direct particular environmental stimuli onto receptor cells
What is the receptor potential and what does it do?
Voltage change caused by influx of ions because of a stimulus
In some it regulates spike productions; in others it directly regulates synaptic transmission
What is a propioceptor?
A sense organ that monitors the position or change in position of an animals body parts - e.g. crayfish abdominal stretch receptor
How is stimulus strength encoded? (in receptor cells that produce spikes)
Spike rate
Which 2 types of neurons use the same code?
Ones that connect eye with the brain and ear with the brain
Who investigated the relationship between spike rate and stimulus strength?
Lord Edgar Adrian 1926 - muscle stretch neurons in frog neck muscles
What is sensory adaption?
When the response wanes if stimulus is maintained
What does sensory adaption allow?
Sensitivity to changing stimuli
Anti-tickle
Which type of sensory adaption is quicker?
Physical (over tonic)
What does the lateral line system of fish do?
Contains ‘hair cells’ that detect movement of water
What features of sounds to animals discriminate?
Tone (frequency)
Loudness (amplitude)
Source (left/right; up/down)
Which end of the cochlea is stiffest?
Near the base
What is the tonotopic organisation of the mammalian cochlea?
Higher frequency tones stimulate auditory nerves near base of basilar membrane, lower and the end
What numbers of inner hair cells; synapses with sensory neurons; and motile outer hair cells do humans have?
Inner hair cells - 3,500
Synapses - 40,000
Motile outer hair cells - 12,500
