You scored 100% by answering 4 out of 4 questions correctly. 1. A very intense stimulus can sometimes stimulate sensory neurons that have evolved for a different modality. Thus, with a blow to the eye, one “sees stars. ” In this example the photoreceptors in the eye are responding to You correctly answered: c. intense pressure. 2. Olfactory receptor neurons respond to low concentrations of chemical odorants because there are membrane proteins in the receptor ending of this sensory neuron that You correctly answered: b.
can bind and respond to the specific odorant. 3. The sequence of events starting with a sensory stimulus and ending with a change in membrane potential is called You correctly answered: c. sensory transduction. 4. Starting at a resting membrane potential of -70 mV, a change to which of the following represents the largest receptor potential? You correctly answered: d. a change to -50 mV 010/27/13 page 4 Review Sheet Results 1. Sensory neurons have a resting potential based on the efflux of potassium ions (as demonstrated in Activity 1).
What passive channels are likely found in the membrane of the olfactory receptor, in the membrane of the Pacinian corpuscle, and in the membrane of the free nerve ending? Your answer: I believe the efflux of K+ ions is managed by passive K+ channels 2. What is meant by the term graded potential? Your answer: They are changed in the membrane potential that are either hyperploarizing or depolarizing. 3. Identify which of the stimulus modalities induced the largest amplitude receptor potential in the Pacinian corpuscle.
How well did the results compare with your prediction? Your answer: My prediction was right. The moderate-intensity pressure did reduce a receptor potential of the largest amplitude in the pacinian corpuscle. 4. Identify which of the stimulus modalities induced the largest amplitude receptor potential in the olfactory receptors. How well did the results compare with your prediction? Your answer: My prediction was right. The moderate-intensity chemical did reduce a receptor potential in the olfactory receptors. 5.
The olfactory receptor also contains a membrane protein that recognizes isoamylacetate and, via several other molecules, transduces the odor stimulus into a receptor potential. Does the Pacinian corpuscle likely have this isoamylacetate receptor protein? Does the free nerve ending likely have this isoamylacetate receptor protein? Your answer: I believe that they both do not have this recptor protein because neither of them responded to the chemical stimuli in this activity. 6. What type of sensory neuron would likely respond to the green light? Your answer: I would say the Photosensory neurons. 010/27/13