The Sensory
System
Sensory receptors are specially modified nerve
endings that convert stimuli from the environment into nerve impulses
that are transmitted to the central nervous system.
There are 4 general types of stimuli to which the
sensory receptors of common animals are sensitive:
![bullet](_themes/anatomy2/capbul1a.gif) | mechanical |
![bullet](_themes/anatomy2/capbul1a.gif) | thermal |
![bullet](_themes/anatomy2/capbul1a.gif) | electromagnetic |
![bullet](_themes/anatomy2/capbul1a.gif) | chemical |
General terminology
![bullet](_themes/anatomy2/capbul1a.gif) | esthesia = ability to receive sensory
information |
![bullet](_themes/anatomy2/capbul1a.gif) | gustatory = taste |
![bullet](_themes/anatomy2/capbul1a.gif) | ocular, ophthal- = eye |
![bullet](_themes/anatomy2/capbul1a.gif) | olfactory = smell |
![bullet](_themes/anatomy2/capbul1a.gif) | tactile = touch |
![bullet](_themes/anatomy2/capbul1a.gif) | noci = pain |
The General Senses are widely distributed
around the body. Their sensory receptors are not highly
specialized.
![bullet](_themes/anatomy2/capbul1a.gif) | visceral sensations = "interior" sensations
such as hunger & thirst |
![bullet](_themes/anatomy2/capbul1a.gif) | touch (and pressure) |
![bullet](_themes/anatomy2/capbul1a.gif) | temperature |
![bullet](_themes/anatomy2/capbul1a.gif) | proprioception = body position
& movement |
![bullet](_themes/anatomy2/capbul1a.gif) | pain |
The Special Senses are all concentrated in
the head. Their sensory receptors are more highly specialized than
those of the general senses.
![bullet](_themes/anatomy2/capbul1a.gif) | taste
- sensory receptors are located in "taste buds" |
![bullet](_themes/anatomy2/capbul1a.gif) | smell - the olfactory epithelium is located
high in the nasal passages. The olfactory cells detect chemical
substances that dissolve in the mucus overlying the sensory
cells. |
![bullet](_themes/anatomy2/capbul1a.gif) | hearing |
![bullet](_themes/anatomy2/capbul1a.gif) | equilibrium |
![bullet](_themes/anatomy2/capbul1a.gif) | vision |
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