Olfactory receptors are destroyed by formaldehyde.

1. Why does the smell of formaldehyde seem to dissipate during the time you spend in the dissection lab, yet you are able to detect the cologne of someone who just entered the lab? Olfactory receptors are destroyed by formaldehyde. Olfactory receptors adapt to the smell of formaldehyde. Central adaptation has occurred, though olfactory receptors retain sensitivity to other smells. None of these is correct.

2. What is unique about the sense of smell when compared to other special senses? Olfaction travels along only one cranial nerve. Olfaction is a chemical sense. Olfactory stimulation passes through two synapses in the thalamus. Olfactory stimulation is the only type of sensory information that reaches the cerebral cortex directly.

3. Which of these correctly describes the pathway of tasting, starting at the tongue? CNs VII, IX, and X  synapse in medulla  synapse in thalamus  primary sensory cortex Synapse in medulla  CNs VII, IX, and X  medial lemniscus  gustatory cortex  synapse in thalamus Tongue  CNs VII and IX  synapse in pons  CN V  synapse in thalamus  primary sensory cortex None of these is correct

4. Which type of lingual papillae do not contain taste buds? What is their function? Circumvallate papillae/perception of water molecules Umami papillae/perception of glutamate Filiform papillae/provide friction Fungiform papillae/appreciation of texture

5. Which cranial nerve supplies taste buds located in circumvallate papillae? Glossopharyngeal nerve Vagus nerve Trigeminal nerve Facial nerve

6. What is the survival value of being more sensitive to sour and bitter tastes than to sweet and salty ones? Sour acids can damage mucous membranes. Many potent toxins have a bitter taste. Sweet and salty tastes are pleasant, and therefore good for you. 1 and 2 are correct.

7. Why can corneal transplant surgeries be performed between unrelated individuals without the risk of rejection? White blood cells rush to the new cornea to fight off infection. There are no blood vessels in the cornea, so white blood cells cannot attack the foreign tissue. Aqueous humor contains powerful antibiotics. None of these is correct.

8. Which of the following is correct concerning the function of the uvea (vascular tunic)? It stabilizes the shape of the eye and produces collagen fibers. It provides the route for the optic nerve and blood vessels to the eye itself. It regulates the amount of light entering the eye. It secretes and reabsorbs vitreous humor.

9. Which of these statements correctly describes the location of rods and cones on the retina? Rods are located in the macula lutea, but only cones are located in the fovea. Cones are located at the periphery of the retina, rods at the center. Rods and cones are evenly distributed on the retina. Cones are located at the center of the retina, rods at the periphery.

10. Why are rods best suited for night vision? Rods have a low threshold for activation. Rods are primarily located within the fovea. Rods participate in converging pathways. Rods contain several visual pigments.

11. What is the consequence if drainage of aqueous humor through the canal of Schlemm (scleral venous sinus) is blocked? Retinitis pigmentosa, leading to blindness. Age-related macular degeneration. Intraocular pressure increases, leading to glaucoma. Depth perception is lost.

12. At which interface in the human eye is refraction the greatest? Between air and the cornea Between aqueous humor and the lens Between the lens and the vitreous body Between the vitreous body and the retina

13. What processes take place for the lens of your eye to become rounder to focus on nearby objects? Ciliary muscle relax and suspensory ligaments pull at the circumference of the lens. New fibers are added to the lens, increasing its refractive power. Ciliary muscles contract, which reduces tension on the suspensory ligaments. The distance between the lens and the macula lutea changes, which keeps focal length constant.

14. How does vitamin A deficiency affect vision? Photoreceptors are destroyed causing blindness within a few years. The amount of visual pigment in photoreceptors declines, causing poor night vision. The ability of the eyes to accommodate for distance vision decreases. Pupillary reflexes and reflexive eye movement are lost.

15. When an object appears white, what event has happened? Photons of all colors have been absorbed by the object. Photons of all colors have bounced off the object. Rods have been stimulated. 2 and 3 are correct.

16. In what circumstance does colorblindness occur? One or more classes of cones is nonfunctional. Cones are unable to manufacture visual pigments. Certain types of cones are absent. All of the above are correct.

17. What effect does a decrease in phosphodiesterase activity in photoreceptor cells have on vision? Increased neuron response to photons Decreased neuron response to photons Increased visual acuity Increased light sensitivity

18. Visual information from the left half of the combined field of vision _________. Arrives at the visual cortex of the right temporal lobe Arrives at the superior colliculus on the right side Arrives at the visual cortex of the left temporal lobe Arrives at the superior colliculus on the left side

19. What is the function of the auditory tube? It helps amplify sound waves. It allows bacteria to travel from the oropharynx to the middle ear. It permits equalization of pressure on either side of the tympanic membrane. It secretes cerumen.

20. What is the role of the auditory ossicles in hearing? They play a major role in equilibrium. They act as levers that conduct vibrations to the inner ear. They vibrate against the round window and distort the perilymph in the vestibular duct. They play no role in hearing.

21. You are attending an incredibly loud rock concert. What is the reaction of your tensor tympani to the noise? It extends to allow free movement of the auditory ossicles, thus preventing hearing loss. It extends to prevent all movement of auditory ossicles. It contracts to reduce movement of the stapes. It contracts to pull the malleus medially and stiffens the tympanic membrane.

22. Which structures comprise the major subdivisions of the bony labyrinth? Anterior, posterior, and lateral semicircular ducts Middle ear, inner ear, and membranous labyrinth Vestibule, three semicircular canals, and the cochlea Vestibule, saccule, and utricle

23. Where are the sensory receptors that respond to rotational movements of the head? In the utricle and saccule In the anterior, posterior, and lateral semicircular ducts In the cochlear duct In the vestibular duct and tympanic duct

24. The receptors for hearing are located in _____, which is filled with ______. The organ of Corti in the cochlear duct/endolymph Hair cells in the vestibular duct/perilymph The tectorial membrane in the tympanic duct/perilymph None of these is correct

25. Which of the following characteristics of sound determines how loud a sound seems? Decibels Pitch Frequency Amplitude

26. Where do low-frequency sounds vibrate the basilar membrane? Why? Near the round window/perilymph is incompressible Near the oval window/shorter wavelength Far from the oval window/longer wavelength Against the tectorial membrane/pressure waves are created in endolymph of the vestibular duct