IMED1001 Lecture Notes - Lecture 15: Sensory Neuron, Stimulus Modality, Sensory System
12 Jul 2018
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Document Summary
Neurons communicate with each other but how do we excite the first neuron. Sensory neurons from outside the body to up to the brain. The stimulus excites the receptors and they determine whether or not it creates an action potential. Intensity= threshold (the minimum detectable intensity), perceived strength above threshold: quality= e. g. colour, sharpness of pain, pitch of sound etc. What forms of stimulus can actually be detected: mechanical- sense of touch, limb position, hearing, balance etc, chemical-taste, smell, photic-vision, thermal-sense of hot and cold, noxious-pain. Different modalities need to be picked up by different receptors. There are five major divisions of these sensory receptors based on stimuli that they respond to: mechanoreceptors= stretch or pressure, thermoreceptors= hot or cold, photoreceptors= light, chemoreceptors= ph, calcium conc, nociceptors= pain. Sensory transduction: sensory receptors are specialized cells that generate graded potentials called receptor potentials in response to a stimulus, two types pf receptor cells: Can exists in simple form of very complex.
