Biology Study Guide Final Exam Chapter 49

Biology Study Guide Final Exam Chapter 49 - Study Guide:...

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Study Guide: Final Exam Chapter 49: Sensory and Motor Mechanisms 1. Sensations begin as different forms of energy detected by sensory receptors. This energy is converted to action potentials that travel to appropriate regions of the brain. Once the brain is aware of sensations, it interprets them, giving the perception of stimuli. Perceptions such as colors, smells, sounds, and tastes are constructions formed in the brain and do not exist outside of it. Sensory reception begins with the detection of stimulus energy by sensory receptors , cellular system that collects information about the physical world outside the body and inside the organism. 2. The conversion of stimulus energy into a change in membrane potential of a sensory receptor is sensory transduction. The change in membrane potential itself is receptor potential. Receptor potentials are graded potentials; their magnitude varies with the strength of the stimulus. All receptor potentials result from the opening or closing of ion channels in the sensory receptor’s plasma membrane. The strengthening of stimulus energy by cells in sensory pathways is called amplification. Some amplification occurs in the sensory receptors, and signal transduction pathways involving second messengers often contribute to it. Amplification can also take place in the accessory structures of a complex sense organ. The conduction of sensory impulses to the CNS is transmission. The strength of the stimulus and receptor potential affects the amount of excitatory neurotransmitter released by the
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This note was uploaded on 11/04/2010 for the course BIO 107 taught by Professor Abott during the Fall '09 term at UConn.

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Biology Study Guide Final Exam Chapter 49 - Study Guide:...

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