Ch10%20outline - ciliary body (secretes aequeous humor),...

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1 MCB 3209 CH 10 NERVE SENSES: TOUCH AND VISION pp. 263-270 and 286-300 Sensory receptor types Mechanoreceptors (pressure, hearing and balance, nociceptor for pain), thermoreceptors, chemoreceptors (odors, taste and blood chemistry), photoreceptors Coding and perception: Graded receptor potentials transduced into frequencies of action potentials that encode intensity; connections to cortex encode perception Adaptation: Reduction in action potential frequency with constant stimulus: phasic vs. tonic Law of Specific Nervous Energies Pacinian corpuscle and tactile sense free nerve endings and Ruffini endings, pacinian corpuscles, Meissner's corpuscles, root hair plexus somatic sensory path to brain Intensity coding = frequency of action potentials Adaptation and lateral inhibition Rods and cones and vision Anatomy of the eye: anterior and posterior chambers and vitreous chamber, cornea, lens and ciliary muscle fibers for focus (accommodation), pupil (controlled by sympathetic and parasympathetic nerves),
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Unformatted text preview: ciliary body (secretes aequeous humor), rods and cones and retinal pigment epithelium Fields of vision and sensory path to brain: rods or cones, bipolar cells, ganglion cells, amacrine and horizontal cells, lateral geniculate nucleus in the thalamus, cerebral cortex (visual cortex); visual acuity determined by fovea centralis. Light activation of rods (hyperpolarization) leads to action potentials (depolarization) in ganglion cells cis-Retinene + light --> trans-Retinene --> change opsin --> activate transducin --> activate phosphodiesterase --> cleave cGMP to GMP --> block Na channels --> hyperpolarize --> reduce release of inhibitory neurotransmitter --> increase release of excitatory neurotransmitter by bipolar cells --> action potential in ganglion cell Visual cycle and dark adaptation Rods (rhodopsin sensitive to green light preferentially) and cones (three pigments differentially sensitive to red, blue and green light)....
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This note was uploaded on 09/21/2010 for the course MCB 57703 taught by Professor Machen during the Spring '08 term at University of California, Berkeley.

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