NEU 211 Lecture Notes - Lecture 10: Afferent Nerve Fiber, Square Wave, Lamellar Corpuscle
18 May 2016
School
Department
Course
Professor
Document Summary
Receptive field mapping continues up into the primary sensory cortical regions. Final perceptions produced in higher cortical regions. Somatic | includes senses of touch (pressure), pain (nociception), temperature, proprioception (position) 1st order neuron: mechanoreceptors primary sensory afferent axons. 2nd order neuron: (synapse) dorsal column nuclei dorsal column of spinal cord (pns neurons) 3rd order neuron: (synapse) ventral posterior nucleus of the thalamus. 4th order neuron: (synapse) primary somatosensory cortex (parietal lobe) Different from other sensory systems in two ways: receptors distributed throughout the body rather than concentrated in spots. A single receptor can encode intensity, duration, position, and direction. Single stimulus activates many receptors: responds to many different stimuli. Skin | largest organ of the body; composed of 2 layers (epidermis and dermis) Outer layer constantly renewing, ~1000 species of bacteria. Hair | grow from follicles embedded and innervated by free nerve endings that wrap/run parallel to it.
