Sensory System Flashcards
(49 cards)
What do thermoreceptors detect?
Temperature
What do chemoreceptors detect?
Chemical changes
What do nociceptors detect?
Damaging stimuli/pain
What do proprioceptros detect?
Position and movement
What is the receptive field?
The specific area to which a receptor will respond to stimulus
What do sensory receptors transduce an adequate stimuli to?
Depolarisation to generate a receptor generator potential
What does the intensity of the stimuli encode?
The size of the receptor potential
What does the frequency of AP encode?
The intensity of the stimulus
What do receptor potential then generate?
Evoke firing of AP for long distance transmission
Does the amplitude tell us anything about the stimulus?
no
What does the receptive field encode?
The location of the stimulus
What is the duration of a series of AP proportionate to?
The duration of the stimulus
How are AP transmitted to the CNS?
By axons
What 3 types of primary afferent fibres mediate cutaneous sensation?
Aβ
Aδ
C
What are Aβ fibres?
Large myelinated fibres that detect touch, pressure and vibration
What are Aδ fibres?
Small myelinated fibres, detect pain and pressure
What are C fibres?
Unmyelinated fibres that detect pain
What 2 types of primary afferent fibres mediate proprioception?
Aα & Aβ
Where do all afferent fibres enter the spinal cord?
Via the dorsal root ganglion
What are chemoreceptive fibres?
(Aα & Aβ)
Where do chemoreceptive fibres project up?
Straight up through the ipsilateral dorsal columns
Where do chemoreceptive fibres synapse?
In the cuneate and gracile nuclei
Where do chemoreceptive 2nd order fibres cross over?
In the medulla
Remember touch and pressure does not cross over at spinal cord entry
Where do chemoreceptive fibres project from the medulla?
To the thalamus and cortex
