DASC20010 Lecture Notes - Lecture 5: Somatic Nervous System, Peripheral Nervous System, Autonomic Nervous System
5 Aug 2018
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Document Summary
Structure of the pns: afferent, receptors, sense organs, efferent, autonomic (muscle contractions)-skeletal muscles (voluntary action, somatic. How to activate an afferent nerve through reception: 2 different ways to get graded receptor potential: receptor potential, generator potential. Na+ channels: na+ entry initiates action potential in afferent fibre that self propagates to cns. Adaptation: tonic receptors: stimulus depends on type of afferent nerve, tonic receptors do not adapt at all, or adapt slowly. It is therefore important that these receptors o not adapt to a stimulus but continue to generate action potentials to relay information to cns. Acuity: receptive field size: receptive field- each sensory neuron responds to stimulus information only within a circumscribed region of the skin surface surrounding it. Photoreceptors: light comes in & hits the retina. Hair cells: transfer mechanical forces of sound into electrical impulses of hearing (action potentials propagating auditory messages to the cerebral cortex) Balance: vestibular apparatus: semi-circular canals, proprioception, vision, cutaneous input.
