Answer to Question 1
Answer: Physical stimuli such as light, sound pressure, or chemicals interact with specialized receptors in a sensory organ. These receptive neurons show graded changes in their membrane
potentials in response to the occurrence of a physical stimulus. The transduction process in effect converts physical energy to a change in neuron electrical potential/action potentials.
Answer to Question 2
Answer: The lateral geniculate nucleus of the thalamus (LGN) is organized into six layers. The inner two layers contain large cells (magnocellular), while the outer four layers are comprised of small cells. The magnocellular layers project to portions of the striate cortex that mediate visual processes other than color (e.g., form, movement, and depth). The parvocellular layers are involved in the perception of color and fine detail.
Regions of the Hypothalamus Involved in Eating and Metabolism
Historian James Merrell notes several errors in Benjamin West’s famous 1771 painting, William Penn’s
Color mixtures of refracted light—additive process.
Examples of Sensory Receptors
First-order sensory neuron with free nerve endings
The Process of Sperm Formation