NROC64H3 Lecture : Somatic Sensory System (nearly word-for-word what was said in lecture)
Document Summary
Receptors = distributed throughout (esp on skin surface) Slide 6: touch, what receptors are involved, primary afferent neurons axons if coming from foot, spinal cord, which pathways subserve touch, somatosensory cortex o. Relay info directly from skin to the brain (may have very long. Connects to a cell that isn"t a nerve itself. In skin covered with mucus, have other receptors like: kraus end bulbs (similar to. Slide 10: differences, differ in terms of receptive fields . Meissner"s corpuscles and pacinian corpuscles have higher degree. Aps at the onset of mounting pressure and then it discontinues. Pacinian corpuscles are most responsive to higher freq; meissner"s corpuscles are responsive to frequencies around 50 hz (skin slip info) So these mechanoreceptors show diff properties in terms of adaptation, which doesn"t necessarily have to do with the nerve endings themselves, but rather with what they"re wrapped in. Y-axis threshold if low, means high sensitivity = very little stimulation will create a response.