III. Sensory Processes

A. Sensory Pathway B. Types of receptors C. Example auditory

1. Sensory reception

• Sense organ; receptors + associated cells 

2. Sensory transduction

• Energy of stimulus converted to receptor potential 

• Unstimulated

  • -> Resting potential

• Stimulated

  • Depolarized -> triggers AP

3. Transmission

• Sensory info travels as AP - receptor -> brain

• Large receptor potential -> more frequent AP

4. Perception

• Brain processes info

• Exists only in brain

• Characterized by type of stimulus transducted

• Chemoreceptors 

• Photoreceptors

• Mechanoreceptors 

• Thermoreceptors 

Example auditory

• Reception: vibration depolarize hair cells in cochlea (graded potentials)

• Transduction: causes AP in auditory nerve 

• Transmission: auditory nerve carries AP to brain

• Perception: brain interprets AP as sound