生理学英文课件(感觉器官)Sense organs.pptVIP

Sense organs Wen-jun Xin xinwenjun2002@ Introduction Why did studied this chapter? Classification: Basic concepts 1: the concept of receptor or sense organs: The special structure or device, which localized in the skin or organs, can sense the change of external world or internal enviroment. Classification by the structure: the end of axon; Capsule-like structure; sense organ classification by the character of stimulus: mechanoreceptor; chemoreceptor; thermoreceptor and opticreceptor Classification by localazation: externalreceptor; internalreceptor and proprioceptors General properties of receptor 1: adequate stimulus: It is common properties, every receptor have its own most sensetive stimuli. The transduction and receptor potential Transduction: receptor can conversed the energy of stimulus into the electric energy of action potential. Receptor potential and generator potential Both is Slow potential transitional, like end-plate potential. The encoding of receptor 编码作用是指感受器把刺激包含的环境变化的信息转移到了新的电信号系统即动作电位的序列之中。 ① 外界刺激质的编码② 外界刺激“量”或“强度”的编码　　信息每通过一次神经元间的传递，都要进行一次再编码 Adaptation of receptor The sensitivity of receptor to adequate stimulus with continued unchanged intensity attenuated. The mechanism is frequency of action potential on fiber decreased 1) rapidly adapting receptor and slowly adapting receptor Visual sense organ The common activities of eye, optic nerve and optic cortex formed Vision The basic structure of eye Eye is affiliated organ of visual system, including dioptric system (cornea, aqueous humor, lens and vitreous humor) and photographic system (retina and optic nerve fiber) The adequate stimuli is Electromagnetic waves, its wavelength 380-760nm . The lens system of eye The refraction principles Physical principles of optics 1:Refraction of light: the ratio between velocity of light in air via the velocity in the substance. Such as: light travel through a glass from air. 2: Refraction of light at an interface between tw