5 Somatosensitivity, viscerosensititvity, proprioception and pain I The role of nervous system Input Integration Output REGULATIONREGULATION Potential input Potential output ANTICIPATIONANTICIPATION Sensor Effector Cortex Cortex The division of nervous system http://wikimedia.org/ The division of nervous system http://wikimedia.org/ Receptors/sensors • Energy convertor – Signal reception – Signal transformation • Receptor potential • Generator potential • Action potential • Adequate stimulus • Non adequate stimulus • Mechanoreceptors • Thermoreceptors • Chemoreceptors • Fotoreceptors http://www.slideshare.net/CsillaEgri/presentations Receptor/generator and action potential http://www.slideshare.net/drpsdeb/presentations Receptors/sensors • Energy convertor – Signal reception – Signal transformation • Receptor potential • Generator potential • Action potential • Adequate stimulus • Non adequate stimulus • Mechanoreceptors • Thermoreceptors • Chemoreceptors • Fotoreceptors http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors • Energy convertor – Signal reception – Signal transformation • Receptor potential • Generator potential • Action potential • Adequate stimulus • Non adequate stimulus • Mechanoreceptors • Thermoreceptors • Chemoreceptors • Fotoreceptors http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors • Energy convertor – Signal reception – Signal transformation • Receptor potential • Generator potential • Action potential • Adequate stimulus • Non adequate stimulus • Mechanoreceptors • Thermoreceptors • Chemoreceptors • Fotoreceptors http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors • Energy convertor – Signal reception – Signal transformation • Receptor potential • Generator potential • Action potential • Adequate stimulus • Non adequate stimulus • Mechanoreceptors • Thermoreceptors • Chemoreceptors • Fotoreceptors http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors • Energy convertor – Signal reception – Signal transformation • Receptor potential • Generator potential • Action potential • Adequate stimulus • Non adequate stimulus • Mechanoreceptors • Thermoreceptors • Chemoreceptors • Fotoreceptors http://www.slideshare.net/CsillaEgri/presentations Intensity coding • Amplitude of receptor potential is transtucted into the frequency of AP http://www.slideshare.net/CsillaEgri/presentations Intensity coding • In hte other words: an increased intensity is associated with increase in frequency of AP • A high-intensity stimulus may also activate more receptors http://neuronresearch.net/neuron/files/neuralcode.htm Intensity coding Relation between receptor and action potential is logarithmic http://slideplayer.cz/slide/3217923/ Amplitudeofreceptorpotential Actionpotentialfrequency Stimulus intensity Stimulus intensity Qualitative information • The law of specific nerve energies: The nature of perception is defined by the pathway over which the sensory information is carried • Labeled line coding define the information about quality http://www.slideshare.net/drpsdeb/presentations Qualitative information • Labeled line coding • Receptive field • Nerve stimulation mimics receptor stimulation http://www.slideshare.net/drpsdeb/presentations Receptive fields • Various size and overlay • Small receptive field – high resolution • Spatial resolving power increased by lateral inhibition http://www.slideshare.net/drpsdeb/presentations Lateral inhibition http://www.slideshare.net/drpsdeb/presentations Receptor adaptation • The decline of receptor responses in spite of stimulus presence • Tonic receptors – slow adaptation – presence of stimulus, position • Phasic receptors – rapid adaptation – change of stimulus http://www.slideshare.net/CsillaEgri/presentations Receptors • Simple • Complex • General – Superficial – somatosensors – Deep – viscerosensors – Muscles, tendons, joints – proprioceptors • Special – Part of sensory organs • Mechanoreceptors • Termoreceptors • Chemoreceptors • Fotoreceptors Receptors • Simple • Complex • General – Superficial – somatosensors – Deep – viscerosensors – Muscles, tendons, joints – proprioceptors • Special – Part of sensory organs • Mechanoreceptors • Termoreceptors • Chemoreceptors • Photoreceptors Receptors • Simple • Complex • General – Superficial – somatosensors – Deep – viscerosensors – Muscles, tendons, joints – proprioceptors • Special – Part of sensory organs • Mechanoreceptors • Termoreceptors • Chemoreceptors • Photoreceptors http://www.slideshare.net/CsillaEgri/presentations