Sensory Receptors

Sensory receptors are dendrites that detect stimulation. The exteroceptors detect stimuli from outside the body while the introceptores detect stimulation on the inside of the body. These interoceptors are directly involved with homeostasis.

"The sensory receptors involved in taste and smell contain receptors that bind to specific chemicals. Odor receptors in olfactory receptor neurons, for example, are activated by interacting with molecular structures on the odor molecule. Similarly, taste receptors (gustatory receptors) in taste buds interact with chemicals in food to produce an action potential.

Other receptors such as mechanoreceptors and photoreceptors respond to physical stimuli. For example, photoreceptor cells contain specialized proteins such as rhodopsin to transduce the physical energy in light into electrical signals. Some types of mechanoreceptors fire action potentials when their membranes are physically stretched.

The sensory receptor functions as the first component in a sensory system.

Sensory receptors respond to specific stimulus modalities. The stimulus modality to which a sensory receptor responds is determined by the sensory receptor's adequate stimulus.

The sensory receptor responds to its stimulus modality by initiating sensory transduction. This may be accomplished by a net shift in the initial states of a receptor(see a picture of these putative states [1] with the biophysical description - link [2])."

There are different types of sensory receptors. There is the Chemorceptors that respond to a chemical substance. The pain receptors that respond to damaged tissue. They alert us to possible danger. The photoreceptors respond to light energy. That is why our eyes dilate. The mechnoreceptors are stimulated by mechanical forces which is usually a result of pressure. Thermoreceptors are stimulated by temperature change.

Once the nerve is stimulated it sends a singal to the brain.