Part I Sensory receptors specialized nerve cells that transduce energy into neural signals “ mode specific Law of Specific Nerve Energies: sensory messages are carried on separate channels to different areas of the brain detect a small range of energy levels Eye:400-700nM Ear:20-20,000Hz Taste buds: specific chemicals
Part 1 Sensory Receptors • specialized nerve cells that transduce energy into neural signals • “mode” specific – “Law of Specific Nerve Energies”: sensory messages are carried on separate channels to different areas of the brain • detect a small range of energy levels – Eye: 400-700 nM – Ear: 20-20,000 Hz – Taste buds: specific chemicals
Spectrum of the electromagnetic Wave ncreasing energy M Increasing wavelength 0.001 11010000.011 100 n nm nmnm cmcm X- UV Gamma rays rays light Infrared Microwaves Radio waves Visible light 380430 500 560600650 750 nm nm nm n
Spectrum of the Electromagnetic Wave
Somatic Sensory Free nerve e Expanded tip Tactile hair receptor Nerve Endings Pacinian Aeissner's Krauses corpuscle corpuscle corpuscle Ruffini's Golgi tendon Muscle endings apparat spindle Hall: Guyton and Hall Textbook of Medical Physiology, 12th Edition Copyright 2011 by Saunders, an imprint of Elsevier, Inc, All rights reserved
Somatic Sensory Nerve Endings
Stimulus Free Nerve endings Free nerve endings dendrites interspersed among other Unmyelinated cells/tissues pain, temperature, touch Cell body Simple neural receptor
Free Nerve Endings • dendrites interspersed among other cells/tissues • pain, temperature, touch
Encapsulated Stimulus Nerve endings Layers of connective tissue Enclosed nerve nding · dendrites with special supporting structures Myelinated axor · mechanoreceptors Cell bod and proprioceptors Comley neural redentor
Encapsulated Nerve Endings • dendrites with special supporting structures • mechanoreceptors and proprioceptors