The major sensory organs are the nose, eye, ear, tongue, and skin. Vision, taste, smell, and hearing are considered to be special senses. Pain, temperature, and pressure are called somatic senses. Sensory receptors react to stimuli in the from of energy, which is turned into action potential and sent to the central nervous system.
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Sensory receptors are classified based on what type of energy they can detect and react to.
- Mechanoreceptors: hearing and balance
- Photoreceptors: light
- Chemoreceptors: smell, taste, internal sensors in digestive and circulatory systems
- Thermoreceptors: temperature
- Electroreceptors: electrical currents