2007 Sensory Physiology

Primary Objective

Auditory system:

1. From a physiological perspective, describe how sounds are transmitted through the middle ear, into the scalae, to cause basilar membrane movement.
2. Define the place principle, and understand what this means in terms of how complex sounds are encoded in the cochlea (i.e., relate frequency coding to Fourier analysis).
3. Describe the hair cell mechanotransduction process, incorporating the concepts of stereocilia deflection, tip links and transduction channels.
4. Compare and contrast the physiological function of inner and outer hair cells.
5. Describe otoacoustic emissions, and their relationship to outer hair cell contractility.  Explain how efferent innervation of outer hair cells can modify acoustic signals.

Visual system:

1. Explain the function of the cornea, iris (pupil) and lens, paying particular attention to the process of accomodation.  List 4 common focusing defects, and methods for their correction.
2. Contrast visual transduction as it occurs in rods and cones.  Outline the specific molecular process that occurs during phototransduction in rods.
3. Diagram how the topographic map is constructed in the lateral geniculate nucleus.
4. Explain how lateral inhibition underlies ganglion cell processing, and contrast the processing of signals in simple vs. complex cells of the visual cortex.
5. Describe visual system evidence for labelled line and pattern theories.

Olfactory system:

1. List six structural dimensions that can be used to classify odourants.
2. Name the olfactory epithelia and the types of receptor cells in each.
3. Define the steps in the olfactory transduction process, differentiating among processing in the main olfactory epithelium (ORNs and GC-D neurons) and the vomeronasal organ (VNO cells).
4. Contrast evidence for labelled line and pattern theories in the processing of olfactory information in the olfactory bulb.