Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University seD Systematic Anatomy Nervous system The conducting pathway Dr Hongqi zhang(张红旗) Email:Zhanghg58@126.com Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University
Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University1 Dr.Hongqi Zhang (张红旗 ) Email: zhanghq58@126.com Systematic Anatomy Nervous system The conducting pathway
General introduction about the nervous pathways Concept Nervours pathway are the routes formed by chains of neurons, through which sensory awareness reaches the cerebral cortex and a motor response is initiated Category of nervous pathways The ascending(afferent or sensory) pathways The descending(efferent or motor) pathways Pyramidal system EXtrapyramidal system Each nervous pathway consists of a chain of tracts and associated nuclei Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University
Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Concept Nervours pathway are the routes formed by chains of neurons,through which sensory awareness reaches the cerebral cortex and a motor response is initiated. Category of nervous pathways: The ascending (afferent or sensory) pathways The descending (efferent or motor) pathways Pyramidal system Extrapyramidal system. Each nervous pathway consists of a chain of tracts and associated nuclei. General introduction about the nervous pathways
Copy riah Ascending(afferent or sensory) pathwar sity Different types of receptors receive different types of stimuli from the external and internal environment and generate corresponding nervous impulse which are conducted upward to the cerebral cortex centers to be processed to give rise to corresponding sensations Superficial sensation touch, pain, temperature& two point discrimination Deep sensations: proprioception, and vibration sense Visceral sensations: hunger. nausea and visceral pain Special sensations: smelling, sight, hearing. taste Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University
Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Ascending (afferent or sensory) pathway Different types of receptors receive different types of stimuli from the external and internal environment and generate corresponding nervous impulse.which are conducted upward to the cerebral cortex centers to be processed to give rise to corresponding sensations. Superficial sensation : touch,pain.temperature & twopoint discrimination. Deep sensations : proprioception,and vibration sense Visceral sensations: hunger.nausea and visceral pain. Special sensations: smelling,sight,hearing.taste
Generally, there are three grades neuron implicated In ascending pathway A chain of three long neurons and a number of interneurons conduct the nerve impulses generated in response to stimuli from an individual receptor to the somatosensory cortex First-order neuron: the cell bodies lie in a dorsal root ganglion or somatic afferent ganglia of cranial nn Second-order neurons: the cell bodies lie within the spinal cord or brain stem such as dorsal column nuclei(sensation of trunk limbs) or sensory nucleus of trigeminal nerve their axons usually decussate, ending in the thalamus Third-order neurons: the cell bodies lie in the thalamus project to the sensory cortex(center) Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University
Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University A chain of three long neurons and a number of interneurons conduct the nerve impulses generated in response to stimuli from an individual receptor to the somatosensory cortex Generally,there are three grades neuron implicated In ascending pathway First-order neuron: the cell bodies lie in a dorsal root ganglion or somatic afferent ganglia of cranial nn. Second-order neurons: the cell bodies lie within the spinal cord or brain stem. such as dorsal column nuclei(sensation of trunk & limbs) or sensory nucleus of trigerminal nerve, their axons usually decussate, ending in the thalamus. Third-order neurons: the cell bodies lie in the thalamus. project to the sensory cortex (center)
Copy righ ANG-Department of Anatomv-Fudan University Sensory and motor pathways lists Trunk and limbs Proprioceptive(deep) sensations pathway Head and face Pathway of pain. T, touch pressure sensation(Sup. sensation) g0o3%茎 Visual pathway Trunk and limbs Pupillary light reflex Head and face Acoustic pathway Equilibratory pathway Visceral sensory pathway General visceral pathway Special visceral pathway Corticonuclear tract pyramidal system Cortospinal tract Cortico-neostriatum-dorsalthalamus-cortex circuit E Extrapyramidal system 1 Neastriatunmo-scubrstaetia nigrtexicrit Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University
Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Copy Right- Hongqi ZHANG-Department of Anatomy-Fudan University Proprioceptive (deep) sensations pathway Pathway of pain.T,touch & pressure sensation (Sup. sensation) Visual pathway Pupillary light reflex Acoustic pathway Equilibratory pathway Visceral sensory pathway: Sensory pathwayGeneral visceral pathway Special visceral pathway Motor pathway Pyramidal system Extrapyramidal systemCortionuclear tract Cortospinal tract Cortico-neostriatum-dorsalthalamus –cortex circuit Neostriatum-substantia nigra circuit Corticoponto-cerebellar–cortex circuit Trunk and limbs Head and face Sensory and motor pathways lists Trunk and limbs Head and face