Sensory Pathology Flashcards
What are the 3 fundamental steps in information processing?
- transduction
- transmission
- perception
What is nociception?
stimulation of nerve cells
What are the required steps of transduction?
- stimulus
- receptor w/ transducer protein present
- ion channels open or close
- membrane potentials change
- AP generation
With regard to tranduction, where does the first AP occur?
first node of Ranvier
What are the two types of receptors for sensation and how do they act?
- somatosensation: 1˚ afferent has receptors
- special senses except olfaction: receptive cells releases neurotransmitter onto 1˚ afferent
What is a receptive field?
spacial region where a stimulus will produce a response (dendrite-defined)
What is a sensory unit?
1˚ afferent + all receptive cells that define its receptor field
What is s stimulus modality?
receptors responding to one type of stimulus preferentially
What is an adequate stimulus?
stimulus TYPE that is the correct modality for a receptor to interpret
What are the three types of energy we can sense?
mechanical
chemical
electromagnetic
What is a nonadequate stimulus?
stimulus not of normal modality for receptor, may be perceived incorrectly as adequate stimulus (conditioned response)
2 ways stimulus intensity can be increased
- frequency
- population (# of cells)
Frequency coding
increased # of APs
Population coding
receptive field overlap
Tonic adaptation
slow adaptation
