Sensory receptors

• The ability to detect changes in the external and internal environment is critical to the survival of organisms
• Sensory receptors respond to the intensity, location and duration of the stimulus
• Stimuli are detected by various receptors which are mostly the dendrites of sensory neurons, specialised to receive the specific stimulus
• There are different types of receptors throughout the human body
• Some receptors respond to external stimuli, other receptors respond to internal stimuli
• Receptors are classified by the stimulus that they detect
• Chemoreceptor - detect changes in chemicals, such as solutes, glucose, water and h+ ions, locations include nose, tongue, carotid arteries, brain
• Thermoreceptor - temperature changes, locations include skin, brain (hypothalamus)
• Mechanoreceptor - sound, touch, pressure, motion, stretch, location include ear, skin, muscles, tendons, ligaments
• Photoreceptor - light, location includes eye
• Nociceptor - detect tissue damage and pain, location include skin, muscles, joints (brain interprets the pain message)