Sensory neurons Flashcards
What is transduction?
Conversion of one form of energy into another e.g sensory cells transducer physical or chemical stimuli to electric signals
What do accessory structures do?
Capture, filter and direct environmental stimuli .e.g end of the eye
What is stimulus intensity initially encoded as?
Amplitude of receptor potential
What is the proprioreceptor in the crayfish abdomen?
A sense organ that monitors the position or change in position of an animals body parts (needed for smooth movement)
What is stimulus strength encoded by?
Spike rate/frequency
What is the adaptation of a sensory neuron?
‘Anti-tickle’: allows sensitivity to changing stimuli and ignore constant stimuli
Is the tonic or phasic receptor more sensitive to changes in the crayfish?
Phasic receptor
Where does sensory transduction occur in the mammalian ear?
Small hair cells that don’t make any spikes
What does sound travel as?
Pressure waves
What features of sounds do animals discriminate?
Tone (frequency of waves)
Loudness (amplitude or intensity)
Source (left right up or down)
What do the motile outer hair cells in the mammalian ear do?
Respond to moving signals coming out of the CNS
Helps regulate sensitivity to sound
Where is the least stiff and most stiff along the basilar membrane of the cochlea?
Least stiff at apex
More stiff at base
What does the variation in stiffness of the basilar membrane mean?
Different parts of the basalt membrane respond to different frequencies
How is loudness encoded?
The receptor potential amplitude in hair cells and then the number of spikes in axon in the auditory nerve
How is tone encoded?
By which hair cells and which auditory nerve axons are excited
Each is tuned to a specific tone= tonotopic organisation
