Homework 5: Sensory systems

This assignment is optional. If you decide to complete it, turn it in at the beginning of the "final" exam. In order to get credit for it you must pick an answer sheet from Mani or Sarah, and use it to fill out your answers.  We will not accept hand written answers on a hardcopy of this file.

Multiple choice (0.5 points each, 20 points total)

1.  Regardless of the nature of a stimulus, sensory information is sent to the CNS in the form of:

1. dendritic processes
2. action potentials
3. neurotransmitter molecules
4. receptor potentials
5. generator potentials

2.  A membrane depolarization that leads to an action potential in a sensory neuron is:

1. a labeled line
2. a hyperpolarization
3. a receptor potential
4. an action potential
5. a postsynaptic potential

3.  Receptors present in the walls of blood vessels and in portions of the digestive and urinary tract that detect stretch are

1. interoreceptors
2. proprioreceptors
3. mechanoreceptors
4. interoreceptors
5. a and c are true.

4.  Pacinian corpuscles in the skin:

1. detect pressure
2. are unencapsulated receptors
3. are simple receptors
4. are complex receptors
5. a and c are true

5.  Examples of proprioreceptors that monitor the position of joints and the state of muscle contratcion are:

1. Pacinian and Meissner's corpuscles
2. baroreceptors
3. muscle spindles
4. Golgi tendon organs
5. c and d are true

6.  The anterior, transparent part of the fibrous tunic is the:

1. cornea
2. lens
3. sclera
4. choroid
5. retina

7.  The thick, gel-like fluid that helps support the structure of the eyeball is the:

1. aqueous humor
2. vitreous humor
3. perilymph
4. endolymph
5. ground substance

8.  The retina is:

1. the vascular tunic
2. the fibrous tunic
3. the sensory tunic
4. the outermost eye tunic
5. c and d are true

9. The CNS interprets sensory information entirely on the basis of the:

1. strength of the action potential
2. number of generator potentials
3. labeled line over it which arrives
4. frequency of action potentials
5. c and d are true

10. A tactile receptor that is composed of dendritic processes that lie within a series of concentric connective tissue layers is a ___________.

1. Ruffini's corpuscle
2. Pacinian corpuscle
3. Meissner's corpuscle
4. Merkel's disc
5. root hair plexus

11.There are _________ primary taste sensations.

1. 2
2. 5
3. 12
4. 20
5. more than 50

12. The loudness or intensity of a sound wave is related to its __________.

1. amplitude
2. frequency
3. duration
4. decibels
5. action potential strength.

13. Put these structures in the correct order in which sound waves are transmitted for hearing.

1. malleus
2. oval window
3. tympanic membrane
4. stapes
5. endolymph
6. perilymph
7. incus

1. 1-7-4-3-2-5-6
2. 3-1-7-4-2-6-5
3. 2-1-7-4-3-6-5
4. 3-2-1-7-4-6-5
5. 3-1-4-7-2-5-6

14. The primary purpose of the auditory ossicles is __________.

1. to equalize pressure in the middle ear
2. to amplify vibration
3. to dampen vibration
4. to transmit otitis media
5. none of these

15. Sound waves are converted into mechanical movements by the __________.

1. auditory ossicles
2. cochlea
3. oval window
4. round window
5. tympanic membrane

16. The basic receptors in the inner ear are the __________.

1. utricles
2. saccules
3. hair cells
4. supporting cells
5. ampullae

17. The structure that separates the cochlear duct from the tympanic duct is the __________.

1. tectorial membrane
2. basilar membrane
3. membranous labyrinth
4. bony labyrinth
5. stapedius

18. Coding sound for pitch is a function of the __________.

1. tectorial membrane
2. basilar membrane
3. vestibular membrane
4. endolymph
5. perilymph

19. Low frequency sound waves create their maximum displacement of the basilar membrane:

1. near the stiff end close to the oval window
2. near the flexible and wide end at the tip of the cochlea
3. in the middle
4. no displacement of basilar membrane at all
5. instead displace the utricle

20. Louder noises result in _________ action potentials in the sensory neuron.

1. taller
2. more frequent
3. less frequent
4. shorter
5. broader

21. What we perceive as the pitch of a sound is our sensory response to its __________.

1. amplitude
2. wavelength
3. frequency
4. intensity
5. duration

22. Sound waves are transmitted directly into the inner ear by movements of the __________.

1. auditory ossicles
2. cochlea
3. oval window
4. round window
5. tympanic membrane

23. The frequency of a sound is indicated to the nervous system by the __________.

1. frequency of hair cell vibration in organ of corti
2. number of hair cells that are stimulated
3. region of the basilar membrane that is deformed
4. movement of the perilymph in the cochlear duct
5. frequency of vibration of the tectorial membrane

24.The following is a list of the steps that occur in the production of an auditory sensation.

1. The pressure wave distorts the basilar membrane on its way to the round window.
2. Movement of the tympanic membrane causes displacement of the malleus.
3. Displacement of the stereocilia stimulates sensory neurons of the cochlear nerve.
4. Movement of the malleus causes movement of the incus and stapes.
5. Distortion of the basilar membrane forces the hair cells of the organ of Corti toward or away from the tectorial membrane.
6. Movement of the oval window establishes pressure waves in the perilymph of the vestibular duct.

The proper sequence for these steps is:

1. 2,4,1,6,5,3
2. 2,4,6,3,5,1
3. 2,1,4,6,5,3
4. 2,4,6,1,5,3
5. 2,5,4,6,1,3

25.When the basilar membrane causes deformation of hair cells of the organ of corti:

1. the deformation is converted into mechanical energy
2. the hair cells are permanently damaged
3. there is a change in the transmembrane potential of the hair cells
4. nausea occurs
5. the cells become unresponsive and no change occurs

26. The ciliary muscles help to __________.

1. control the amount of light reaching the retina
2. control the shape of the lens
3. control the production of aqueous humor
4. move the eyeball
5. none of the above

27.An area of the retina that contains only cones and is the site of sharpest vision is the __________.

1. outer segment
2. inner segment
3. fovea
4. optic disc
5. tapetum lucidum

28. When all three cone populations are stimulated equally, we see __________.

1. red
2. blue
3. green
4. white
5. black

29. A blind spot in the retina occurs where __________.

1. the fovea is located
2. ganglion cells synapse with bipolar cells
3. photoreceptors are absent, as the optic nerve leaves the eye
4. rod cells are clustered to form the macula
5. amacrine cells are located

30. Light absorption requires the presence of __________.

1. rods
2. cones
3. visual pigments
4. sodium pumps
5. neurotransmitters

31. The amount of light reaching the retina is controlled by the __________.

1. lens
2. iris
3. optic disk
4. ciliary muscle
5. more than one of these

32. The quantity of neurotransmitter that is released by a rod:

1. increases in the light.
2. is greater in the dark
3. increases when the rod is hyperpolarized
4. increases when the rod is depolarized
5. b and d are true

33. Damage to the fovea of the eye would interfere with the ability to __________.

1. focus an image
2. regulate the amount of light striking the retina
3. bleach visual pigments
4. see black and white
5. see color

34. When a rod cell in the eye is stimulated by light, __________.

1. the cell becomes depolarized
2. inactive form of retinal associates with bleached opsin
3. more neurotransmitter is released
4. sodium channels are opened
5. the cell becomes hyperpolarized

35. In the dark, rhodopsin is not active and sodium channels are _________. Neurotransmitter release is _________. In bright light, the sodium channels are _________ and neurotransmitter release _________.

1. closed/continuous/closed/increases
2. open/continuous/closed/ceases
3. closed/continuous/open/ceases
4. open/absent/closed/increases
5. none of the above

36. The fibers of what cells form the optic nerve?

1. photoreceptor cells
2. bipolar cells
3. ganglion cells
4. amacrine cells
5. horizontal cells

37. During the period of dark adaptation:

1. rods are being bleached out
2. rhodopsin is being regenerated
3. rods are inactivated
4. cones are activated
5. a and c are true

38. The olfactory nerve:

1. is found bundled in the olfactory bulbs.
2. is formed by fibers of olfactory receptor cells
3. is formed by fibers of mitral cells
4. is a mixed nerve
5. is a motor nerve

39.  Which of the following are complex receptors:

1. rods
2. Pacinian corpuscles
3. muscle spindles
4. Golgi tendon organs
5. all of the above

40.  Which of the following are tonic receptors:

1. temperature receptors
2. Pacinian corpuscles
3. muscle spindles
4. touch receptors
5. a and c are true