Physiology 2130 Lecture Notes - Lecture 7: Tectorial Membrane, Muscle Spindle, Visual System
Document Summary
Necessary for body to detect changes in external environment. Homeostasis: the maintenance of stable internal environment, despite changes in external environment. Different sensory system allow detection of changes in external environment. Transduction of environmental information: how information from external environment turned into action potentials. Sensory receptors: detect environmental stimuli (energy) and convert information to action potentials. Opens ion channels, causes depolarizationof sensory neuron producing action potential. Chemical stimulus: binds sensory receptors on tongue or nose. Photoreceptors of eye: absorb light energy and produce action potentials. Gravity and motion: detected by hair cells in vestibular system converting these stimuli to action potentials. Adequate stimulus: the form of environmental stimulus to which the sensory receptor is most sensitive. Ex. rods and cones sensitive to light but still respond to pressure. Sensory receptor: stimulated by environmental stimulus, causing change in ion permeability. Change in permeability: leads to local depolarizationcalled generator/receptor potential. Action potential generated and propagated along axon into spinal cord generator/receptor potential.