Sensory Nerves Flashcards
What is sensory modality?
The type of stimulus a receptor normally responds to
What are mechanoreceptors?
Sensory receptors that are stimulated by mechanical stimuli - touch stretch, pressure, deformation.
Detect many stimuli, balance hearing
What are proprioceptors?
Mechanoreceptors in joints and muscles that signal information information related to body or limb position.
What are nociceptors?
Respond to painful stimuli
What is a graded membrane potential change called in a sensory nerve?
Receptor potential or a generator potential
Transduction always results in the opening or closing of ion channels
Where are action potentials produced from the receptor potential?
Wherever the membrane has voltage gated ion channels
When do you get a higher frequency of action potentials?
When there is a larger stimulus since this causes a larger receptor potential, can also activate more receptors too
What is meant by adaptation of a mechanoreceptor?
When the mechanoreceptor adapts to a maintained stimulus and only signals change or a novel event
Give an example of a sensory receptor that does not adapt?
Nociceptor, because it is important not o ignore a painful stimuli.
What is a pacinian corpsucle responsive to?
Vibration and pressure
Describe the structure of a pacinian corpsucle
Myelinated nerve, naked nerve ending. The nerve ending is enclosed in a connective tissue capsule. This capsule contains layered membrane lamellae separated by fluid.
How are action potentials generated from a pacinian corpsucle
Mechanical stimuli deforms the capsule and nerve ending, causing ion channels to open, - generator potential and then action potential.
How is the pacinian corpsucle capable of rapid adaptation?
Fluid redistribution of corpsucle rapidly dissipates stimulus, nerve ending no longer stretched
What happens to the pacinian corpsucle when the stimulus is withdrawn?
Capsule springs back - more action potentials
What type of structure os the pacinian corpsucle?
Non-neural accessory structure
