Bild 2_Ch 49 - Ch 49 Sensory and Motor Mechanisms 9:41:00...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Ch. 49: Sensory and Motor Mechanisms 20/02/2008 00:41:00 1. Describe the four general functions of receptor cells as they convert energy  stimuli into changes in membrane potentials and then transmit signals to the central  nervous system. Sensory receptors perform four functions in the process of converting energy  (from stimuli) in to a change in membrane potential o Sensory transduction: the conversion of stimulus energy into a change  in the membrane potential of a sensory receptor Receptor potential: change in membrane potential All receptor potentials result from opening or closing of ion  channels in plasma membrane, which changes the permeability  of the membrane Are extremely sensitive o Amplification: the strengthening of stimulus energy by cells in sensory  pathways Example: action potential of eye to brain is 100,000 times more  energetic than the photons that trigger it o Transmission-after energy in a stimulus has been transduced into a  receptor potential, action potentials are transmitted to the CNS;  magnitude of receptor potential affects the frequency of action  potentials that travel  Sensory receptors as sensory neurons Can produce action potential   A larger receptor potential reaches threshold sooner,  resulting in more frequent action potentials Receptors that don’t have axons and release neurotransmitters  at synapses with sensory neuron Receptor releases excitatory neurotransmitter, causing  sensory neuron to transmit action potentials to CNS A larger receptor potential causes more neurotransmitter  to be released at the synapse, usually with the same  result Many sensory neurons spontaneously generate APs at low rate,  so stimulus modulates AP frequency Alert CNS presence or absence of stimulus and also  changes in intensity or direction
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
o Integration-processing of sensory info begins as soon as info is  received Sensory receptors are integrated trough summation as are  postsynaptic potentials in sensory neurons that synapse with  multiple receptors Sensory adaptation: a decrease in responsiveness during  continued stimulation Occurs at all levels of nervous system 2. Distinguish between sensory transduction and receptor potential. The conversion of stimulus energy into a change in the membrane potential is  call sensory transduction and the change in membrane potential itself is  known as receptor potential Soooo…sensory transduction is the conversion of stimulus into a receptor  potential 3. Explain the difference of sensory adaptation.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern