山东大学基础医学院：《生理学 Physiology》课程PPT教学课件_The Nervous System 神经系统（含感觉器官）感觉功能 Sensory Function of the Nervous System

Chapter 31 Sensory Function of the Nervous system

Chapter 31 Sensory Function of the Nervous System

Contents Sensory receptors and sensory organs Pain The visual system The Auditory systems

Contents • Sensory receptors and sensory organs • Pain • The visual system • The Auditory Systems

Section 1 Sensory receptor and sensory organ

Section 1 Sensory Receptor and Sensory Organ

Part I Sensory receptors specialized nerve cells that transduce energy Into neural signals mode specific aw of Specific Nerve Energies(神经 特殊能量 定律)” sensory messages are carried on separate channels to different areas of the brain detect a small range of energy levels Ee: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（神经特殊能量 定律）”: 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 Increasing energy← M Increasing wavelength 0.001 11010000.01 100 nm nm nmnm cm cm X- UV Gamma rays rays light Infrared Microwaves Radio waves Visible light 380 430 500 560600650 750 nm nm nm nm nm

Spectrum of the Electromagnetic Wave

Somatic Sensory nerve endings Free nerve Expanded tip Tactile hair endings receptor Pacinian Meissner Krause's corpuscle corpuscle corpuscle Ruffini's Golgi tendon Muscle end-organ apparatus spindle

Somatic Sensory Nerve Endings

Stimul 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 limulus Nerve endings Layers of connectiv closed nerve nding dendrites with special supporting structures Myelinated axor mechanoreceptors Cell body and proprioceptors Comley naural reenter

Encapsulated Nerve Endings • dendrites with special supporting structures • mechanoreceptors and proprioceptors

Classification of receptors Location Exteroceptors Located on the body surface or specialized to detect external stimuli Pressure, pain, temp touch, etc Ⅴ isceroceptor within internal organs, detect internal stimuli Blood pressure, pain, fulness proprioceptors Limb and body position and movement in the joints and muscles in the vestibular structures and the semicircular canals of the inner ear

Classification of Receptors: Location • Exteroceptors – Located on the body surface or specialized to detect external stimuli – Pressure, pain, temp, touch, etc. • Visceroceptor – within internal organs, detect internal stimuli – Blood pressure, pain, fullness. • Proprioceptors – Limb and body position and movement. – in the joints and muscles – in the vestibular structures and the semicircular canals of the inner ear

Classification of receptors: Modalities Mechanoceptive Detects stimuli which mechanically deform the receptor Pressure vibration touch. sound Thermoceptive Detects changes in temperature hot/cold Nociceptive(pain) Detects damage to the structures Photoreceptors Detect light; vision, retinal of the eye Chemoceptive Detect chemical stimuli CO2 and O2 in the blood, glucose, smell, taste

Classification of Receptors: Modalities • Mechanoceptive – Detects stimuli which mechanically deform the receptor; – Pressure, vibration, touch, sound. • Thermoceptive – Detects changes in temperature; – hot/cold • Nociceptive (pain) – Detects damage to the structures • Photoreceptors – Detect light; vision, – retinal of the eye • Chemoceptive – Detect chemical stimuli – CO2 and O2 in the blood, glucose, smell, taste