Univ. of Illinois, Urbana-Champaign Bio/Neuro 303 Chapter 12 - Study Questions *** LAST UPDATED 05 October 2002 *** 151. Hair cells in the cochlea respond to a stimulus by a. opening Na+ channels and hyperpolarizing. b. opening Na+ channels and depolarizing. *c. opening K+ channels and depolarizing. d. opening K+ channels and hyperpolarizing. 152. Transduction in the mammalian ear takes place in or on the a. tympanic membrane. *b. cochlea. c. semi-circular canals. d. ear drum. 154. Deflections of the hairs on hair cells in the cochlea are produced by shear stress induced by the relative movement of the a. basilar and tympanic membranes. b. tympanic and tectorial membranes. c. tympanic and vestibular membranes. *d. basilar and tectorial membranes. 155. In the cochlea of the mammalian ear, the "hairs" of the hair cells (not the cells themselves) are attached to the *a. tectorial membrane. b. basilar membrane. c. Reissner's membrane. d. tympanic membrane. 156. In the cochlea of the mammalian ear, the hair cells (not the "hairs" that are part of them) are attached to the a. tectorial membrane. *b. basilar membrane. c. Reissner's membrane. d. tympanal membrane. 157. In the mammalian cochlea, high frequency sounds cause the greatest displacement of a. the entire basilar membrane. b. about half of the basilar membrane. c. a small portion at the broad end of the basilar membrane. *d. a small portion at the narrow end of the basilar membrane. 159. The sense cells in a neuromast organ are structurally most similar to which of the following sense cells? a. Mechanoreceptive hair cells in an insect. b. Rods in a vertebrate retina. *c. Hair cells in the mammalian cochlea. d. Olfactory receptors in a mammalian nasal passage. 161. The tectorial membrane is part of a sense organ specialized for a. vision. b. touch. c. proprioception. *d. hearing. 162. Which of the following is NOT a part of the sound reception (i.e., transduction) apparatus of a mammalian ear? a. Basilar membrane. b. Tectorial membrane. c. Hair sense cells. *d. Auditory nerve. 163. Several mechanisms have been found to help sharpen the tuning of individual hair cells in the mammalian cochlea. One of these mechanisms is *a. electrical tuning of the hair cells. b. electrical tuning of the tympanic membrane. c. mechanical resonance of the bones of the inner ear. d. mechanical resonance of the cochlear nerve 164. In mammals, the auditory nerve first makes synaptic connections in the brain in the a. nucleus of the lateral lemniscus. b. thalamus. *c. cochlear nucleus. d. superior olivary complex. 169. Two-tone suppression in an auditory system is an example of a. efferent control. b. reafference. c. centrifugal control. *d. contrast enhancement. 170. In two-tone inhibition, the tuning curve of the neuron under study _______ when a second tone is presented. *a. narrows b. inverts c. widens d. stays the same 172. In barn owls, thd midbrain homologue of the mammalian inferior colliculus contains a map of *a. the direction in space (azimuth and elevation) of a sound source b. the distance of a sound source from the owl. c. the velocity of a sound source d. all of the above 176. The auditory neuropil of the bushcricket is arranged *a. tonotopically by frequency. b. by the intensity of the sound stimulus. c. by the distance of the sound from the insect. d. by none of the above. 177. Hair cells are the primary receptor cell type in a. hearing organs. b. lateral line organs. c. vestibular (balance) organs. *d. all of the above.