2014 Sensory Physiology

Example questionStimulus Modality


Critical Fact Icon(doctrine of specific nerve energies - Mueller, 1826)


ADEQUATE STIMULUS: the type of energy that a receptor responds to under NORMAL conditions (i.e., the type of energy that has the lowest threshold for receptor activation)

Adequate stimulus cartoon
The principle of specificity does NOT mean that a receptor cannot respond to other forms of energy (e.g., photoreceptors responding to intense pressure). However, due to the segregation of sensory pathways (think of the organization of sensory cortices, with each system in a different physical location), any stimulus is perceived as if it was the adequate stimulus (e.g., pressure on photoreceptors is perceived as "seeing stars").

Special Senses
"Not-so-special" Senses
Audition (hearing)
Mechanoreception (touch)
includes both somatosensation and visceral sensation
(e.g., blood pressure)
Vision (sight)
includes both somatosensation and visceral sensation
Gustation (taste)
Body position (part of proprioception)
Head rotation
Internal sensation: pH, osmolarity
Gravity detection
Olfaction (smell)


Email: Dr. Janet Fitzakerley | ©2014 University of Minnesota Medical School Duluth | Last modified: 4-feb-14 8:26 PM