Sensory Receptors 1 Flashcards
what are sensory receptor?
- nerve endings often with specialised non-neural structures (sinorpuscles)
- transducers which convert different forms of energy
- inform CNS aout internal and external environment
what is sensory modality?
type of stimulus activating a particular receptor (e.g. touch, pressure, pain ,temperature, light)
what is adequate stimulus?
type of energy a receptor usually responds to
what do mechanoreceptors detect?
stimulated by mechanical stimuli (pressure, stretch, deformation) Detect: -hearing -balance -blood pressure - skin sensation like touch and pressure
what do proprioceptors detect?
mechanoreceptors in joints and muscles.
Signal information related to body or limb position
what do nociceptors detect?
respond to painful stimuli (e.g. tissue damage or heat)
what do thermoreceptors detect?
detect cold or warmth
what do chemorecetors detect?
chemical change (pH, pO2, pCO2)
what do photoreceptors detect/respond to?
respond to particular wavelengths of light
what activates the stretch-sensitive ion channels causing ion flow across the membrane?
membrane deformation as a result of adequate stimulus
- causes voltage-gated channels to open that generate APs
what does receptor potential depend on?
stimulus intensity (higher frequency of APs)
what does low stimulus intensity produce?
no APs
what does high stimulus intensity produce?
lots of APs
what is the frequency coding of the stimulus intensity?
the larger the stimulus, the larger the receptor potential, more APs produced with higher frequencies
what do Merkel receptors on skin sense?
steady pressure and texture
what does Meissner’s corpuscle on skin sense?
responds to flutter and stroking movements
what do sensory nerves sense?
carry signals to spinal cord
what does Ruffini corpuscle on skin do?
responds to skin stretch
what does Pacinian corpuscle on skin sense?
senses vibration