11. Sensory systems

10. The retina: a) allows vision in light and dark, using cones and rods b) gives depth perception using binocular vision c) contains the ciliary muscles that control the shape of the lens d) protects and supports the shape of the eye e) controls colour vision

a) allows vision in light and dark, using cones and rods

43. Sound waves: a) are quantified on the decibel scale which is logarithmic b) with an intensity of 0 decibels are inaudible c) may have an intensity of plus 10 decibels d) with an intensity of 90 decibels are usually painful e) are heard as a note one octave higher when their frequency increases eight-fold

a) are quantified on the decibel scale which is logarithmic

26. The basilar membrane of the cochlea vibrates: a) at the same frequency as the applied sound b) with an amplitude which is proportional to the frequency of the applied sound c) with an amplitude which is counter proportional to the loudness of the applied sound d) more along of its length when the applied sound has a high rather than low frequency e) mainly at the base of the cochlea for the sound frequencies commonly used in speech

a) at the same frequency as the applied sound

46. In the visual field of the left eye, an object: a) in the upper temporal quadrant is detected in the lower nasal quadrant of the retina b) at the centre of the field of vision is detected in the optic disc c) focused on the blind spot is in the nasal half of the visual field d) in the temporal half generates impulses which travel the left optic tract e) in the temporal half is more likely to be perceived in binocular vision than one in the nasal half

a) in the upper temporal quadrant is detected in the lower nasal quadrant of the retina

30. Dilation of the pupil: a) increases the amount of light entering the eye and the spherical aberration b) increases the refractive power of the eye c) decreases the spherical aberration d) increases the depth of focus e) increases the field of vision

a) increases the amount of light entering the eye and the spherical aberration

47. An audiogram: a) is a plot of hearing ability (or hearing loss) against sound frequency b) showing equal impairment of air and bone conduction suggests conductive deafness c) showing hearing loss at high frequencies for air conduction suggests ear drum damage d) showing loss at 8000 Hz for air and bone conduction suggests conductive deafness e) showing hearing loss at the lower frequencies is common in elderly people

a) is a plot of hearing ability (or hearing loss) against sound frequency

53. Interruption of the visual pathway in the: a) left optic tract causes blindness in the right visual field (right homonymous hemianopia) b) optic chiasma causes blindness in the nasal half of each visual field (binasal hemianopia) c) left optic radiation causes loss of vision to the left d) occipital cortex causes loss of the light reflex e) occipital cortex causes loss of central vision with preservation of peripheral vision

a) left optic tract causes blindness in the right visual field (right homonymous hemianopia)

16. Nearsightedness is more properly called: a) myopia b) hyperopia c) presbyopia d) emmetropia e) astigmatismus

a) myopia

22. Which skin receptors are the most numerous? a) pain receptors b) heat receptors c) cold receptors d) proprioceptors e) stretch receptors

a) pain receptors

54. Squinting (strabismus) may result from: a) poor vision in one eye in childhood or a refractive error in childhood b) damage to the posterior pituitary c) central suppression of vision in one eye in childhood d) damage to the cerebellum e) damage to the external capsule

a) poor vision in one eye in childhood or a refractive error in childhood

44. The frequency of impulses generated by receptors in an utricle is: a) related to the orientation of the head and reduced in the weightless conditions in outer spase b) higher during travel at 100 than at 20 miles per hour c) not related to the orientation of the head and increased in the weightless conditions in outer space d) inversely related to the frequency being generated by the opposite utricle e) related to the impulse frequency being generated by semicircular canal receptors

a) related to the orientation of the head and reduced in the weightless conditions in outer spase

49. Colour blindness: a) results from inability to detect one of the three primary light colours: red, yellow and blue b) where red and green are indistinguishable is due to failure of red and green cone systems c) in which no colours can be detected is due to failure of all the cones systems d) is more common in women than men e) is a disability linked to the Y-chromosome

a) results from inability to detect one of the three primary light colours: red, yellow and blue

48. In someone with short-sightedness (myopia): a) the eye tends to be longer than average from lens to retina b) a convex lens is required to correct the refractive error c) close vision is affected more than distance vision d) the near-point is farther than normal from the eye e) a circular object tends to appear oval

a) the eye tends to be longer than average from lens to retina

14. The large onion-shaped receptors deep in the dermis and in subcutaneous tissue, which respond to deep pressure are: a) Merkel discs b) Pacinian corpuscles c) free nerve endings d) muscle spindles e) stretch receptors

b) Pacinian corpuscles

8. Intraocular fluid includes: a) lens b) aqueous humour c) cornea d) vitreous humour e) ciliary body

b) aqueous humour

23. Which two body areas were least sensitive to touch? a) neck and shoulders b) back of calf and back of neck c) palm of hand and back of hand d) lips and fingertips e) chest and abdomen

b) back of calf and back of neck

27. The cones in the retina differ from rods in that they are: a) more numerous b) more concerned with colour vision and high visual acuity c) more sensitive to light d) not concerned with high visual acuity e) more affected by vitamin a deficiency

b) more concerned with colour vision and high visual acuity

6. Vitamin A is a precursor for the synthesis of: a) somatostatin b) retinine-1 c) the pigment of the iris d) scotopsin e) aqueous humour

b) retinine-1

34. The tympanic membrane: a) modifies the frequencies of sound waves impinging on the ear b) stops vibrating almost immediately after the sound stops c) bulges outwards when the pharyngotympanic tube is blocked d) transmits sound more effectively when the small muscles of the middle ear are contracted e) continues to vibtate after the sound stops

b) stops vibrating almost immediately after the sound stops

28. Increasing the salt concentration applied to a 'salt' taste bud increases: a) its sensitivity to salt b) the amplitude of its generator potentials and impulse traffic to the thalamus c) the amplitude of the action potentials generated d) impulse traffic to the anterior pituitary e) impulse traffic to the adrenal medula

b) the amplitude of its generator potentials and impulse traffic to the thalamus

31. The olfactory system can detect: a) 20-40 distinct odours b) the direction from which an odour comes and differences in odour between isomers of the same substance c) odours better in young than in old people d) small differences in the concentration of the substance responsible for the odour e) odours better in old than in young people

b) the direction from which an odour comes and differences in odour between isomers of the same substance

2. Regarding the focusing of the eye: a) hypermetropia may be corrected by diverging lens b) the focus of the eye is controlled by parasympathetic innervation of the ciliary body c) the lens is the chief refractive element of the eye d) when the eye focuses on a distant object the ciliary muscle contracts e) the focus of the eye is controlled by sympathetic innervation of the ciliary body

b) the focus of the eye is controlled by parasympathetic innervation of the ciliary body

3. Regarding the physiology of the eye: a) the intraocular pressure is about 1,5 mm Hg b) when light is directed to one eye, both pupils constrict c) the pupils dilate when the eye is focused on a near object d) the aqueous humor is an ultrafiltrate of plasma e) the pupils constrict when the eye is focused on a distant object

b) when light is directed to one eye, both pupils constrict

24. Olfactory cells: a) are epithelial cells which synapse with olfactory nerves b) generate impulses when stimulated which are relayed in the thalamus c) are chemoreceptors d) show little adaptation e) are less important than taste in appreciating the flavour of food

c) are chemoreceptors

40. The rods in the retina: a) contain visual pigment which is more sensitive to red than to blue light b) are rendered sensitive by ordinary daylight c) are more widely distributed over the retina than are cones d) reflect blue light more than red light e) comprise about 20 per cent of foveal receptor cells

c) are more widely distributed over the retina than are cones

32. During accommodation for near vision: a) more light enters the eye b) the curvature of the cornea increases c) chromatic and spherical aberration is decreased and the depth of focus increases d) the depth of focus decreases e) the visual axes of the two eyes diverge

c) chromatic and spherical aberration is decreased and the depth of focus increases

57. In long-sightedness (hypermetropia): a) objects at infinity cannot be focused sharply on the retina b) objects at the usual near-point are focused in front of the retina c) ciliary muscle contracts more strongly to bring objects in mid- visual range into clear focus d) the range of unblurred vision (near-point to far-point) is greater than normal e) the near-point can be brought closer to the eye by the use of a biconcave lens

c) ciliary muscle contracts more strongly to bring objects in mid- visual range into clear focus

37. When light is directed to one eye, the pupil: a) constricts even though its optic nerve has been cut b) responds due to sympathetic nerve activity c) does not respond if autonomic cholinergic nerves are blocked by local application of atropine or if there is brainstem death d) In that eye constricts and the opposite pupil dilates e) respond instead is brainstem is death

c) does not respond if autonomic cholinergic nerves are blocked by local application of atropine or if there is brainstem death

29. On entering a darkened room, the: a) light intensity threshold of the eye starts to rise b) final phase of retinal adaptation is mainly in the cones c) final phase of retinal adaptation is mainly in the rods d) adaptation is quicker if a long period was spent in bright light beforehand e) time course for pupillary dilatation is similar to that for dark adaptation down to the adrenal medula

c) final phase of retinal adaptation is mainly in the rods

20. The transmission of sound vibrations through the internal ear occurs mainly through the: a) nerve fibers b) air c) fluid d) bone e) cartilage

c) fluid

4. Regarding vision: a) protanopes cannot distinguish between red and green because they lack the pigment for detecting green light b) full colour vision is possible in dim light c) full dark adaptation takes nearly 30 min d) in a dark-adapted eye, the visual activity is best in the centre of the visual field e) in the retina there are more ganglion cells than photoreceptors

c) full dark adaptation takes nearly 30 min

33. Visual acuity is: a) a measure of the sensitivity of the retina to light b) greater in a person with 0.5 vision than in one with 0.75 c) greater using central rather than peripheral vision d) greater using one eye than both eyes e) greater in normal than in colour-blind people

c) greater using central rather than peripheral vision

55. Involuntary oscillatory eye movements (nystagmus): a) do not occur in healthy people b) may result from cochlear disease c) occur in cerebellar disease and when hot fluid is run into one external ear canal d) occur when hot fluid is run into one external ear canal e) do not affect acuity of vision

c) occur in cerebellar disease and when hot fluid is run into one external ear canal

39. The tympanic membranes a) bulge outwards during descent in an unpressurized airplane b) have an area about twice that of the oval window c) prevent sound waves from reaching the oval and round windows at the same time d) transmit only 10 per cent of applied sound energy to the cochlea for sound waves of 1000 Hz e) transmit sounds in the 500-5000 Hz frequency range with the least loss of energy

c) prevent sound waves from reaching the oval and round windows at the same time

56. Impairment of visual acuity in bright light can be explained by: a) random light scattering when there is dense pigmentation of the eye b) random light scattering when there is asymmetrical corneal curvature due to astigmatism c) random light scattering in the cornea when there is vitamin A deficiency d) impairment of rod function when there is vitamin A deficiency e) inability to alter the focal length of the lens when a cataract is present

c) random light scattering in the cornea when there is vitamin A deficiency

1. Regarding the receptors in the skin: a) all skin receptor are encapsulated b) the receptive fields of touch receptors are uniform in area c) the nociceptors of the skin are bare nerve endings d) sensory information from the skin reaches the brain via the dorsal pathway e) sensory information from the skin is stored in the hypothalamus

c) the nociceptors of the skin are bare nerve endings

9. What controls not only hearing but also a sense of gravity and motion: a) the incus and the stapes b) the pinna and the ear drum c) the vestibular nerve and the semi circular canals d) the eustachian tube and the stapes e) the mesencephalon

c) the vestibular nerve and the semi circular canals

51. In the middle ear: a) destruction of the auditory ossicles abolishes hearing b) paralysis of the auditory muscles makes sounds more faint c) immobilization of the stapes causes smaller deafness than removal of the ossicles d) air pressure is normally atmospheric pressure e) the round window doesnt move reciprocally with the oval window

d) air pressure is normally atmospheric pressure

41. Cones: a) are found in the most superficial layer of the retina b) show a graded depolarization in response to light c) contain pigments which are more light-sensitive than the rod pigment d) contain pigments which are most affected by yellow-green light e) are absent in an individual with colour blindness

d) contain pigments which are most affected by yellow-green light

19. Cells in the olfactory bulb that act as local 'integrators' of olfactory inputs are the: a) hair cells b) granule cells c) basal cells d) mitral cells e) supporting cells

d) mitral cells

45. Rhodopsin, the pigment of the rods is: a) a purple pigment b) highly absorbent of red light c) most sensitive to violet light d) regenerated in the dark and least sensitive to red light e) not regenerated in the dark light and least sensitive to blue light

d) regenerated in the dark and least sensitive to red light

15. The portion of the fibrous layer of the eyeball that is white and opaque is the: a) choroid b) cornea c) retina d) sclera e) iris

d) sclera

17. Olfactory tract damage would probably affect the ability to? a) see b) hear c) feel pain d) smell e) speak

d) smell

12. Hair cells in the ear: a) are sensory receptors that will fire off action potentials when they are disturbed b) show a graded response, instead of the spikes typical of other neurons c) 'rub' against the overhanging tectorial membrane d) a, and c e) a, b, and c

e) a, b, and c

18. Where are taste buds found? a) anterior part of the tongue b) posterior part of the tongue c) palate d) lips e) a, b, and c

e) a, b, and c

35. In the refracting system of the eye: a) the cornea causes less refraction than the lens b) more refraction occurs at the inner surface of the cornea than at the outer surface c) the lens, by becoming more convex, can more than double the total refractive power of the eye d) the back surface of the lens contributes more to accommodation than the front e) aging reduces the maximum refractive power of the eye

e) aging reduces the maximum refractive power of the eye

11. The sense that certain foods are sweet is due to: a) fungiform papillae b) filiform papillae c) foliate papillae d) circumvallate papillae e) all of the above

e) all of the above

21. Which of the following is important in maintaining the balance of the body? a) visual cues b) semicircular canals c) the saccule d) proprioceptors e) all of the above

e) all of the above

5. In the lens: a) potassium concentration is higher than that of sodium b) the majority of the lens proteins are water soluble c) the osmolarity is higher than that of the aqueous humour d) glutathione is increased in the presence of cataract e) all of the above

e) all of the above

58. Pain receptors in the gut and urinary tract may be stimulated by: a) distention b) inflammation of the wall c) acid fluid d) vigorous rhythmic contractions behind an obstruction e) all of the above

e) all of the above

59. Visceral pain: a) is poorly localized compared with pain arising in skin b) is often felt in the mid line c) may cause reflex contraction of overlying skeletal muscle d) may cause reflex vomiting e) all of the above

e) all of the above

60. Headache can be caused by: a) dilatation of intracranial blood vessels b) meningeal irritation c) blood in the cerebrospinal fluid d) loss of cerebrospinal fluid following lumbar puncture e) all of the above

e) all of the above

61. Severe pain may lead to: a) a fall in blood pressure due to a fall in vascular resistance in skeletal muscle b) a fall in heart rate due to an increase in cardiac vagal tone c) vomiting through a reflex centre in the brainstem d) profuse sweating due to activation of sympathetic nerves e) all of the above

e) all of the above

7. Taste receptors: a) for sweet, sour, salt and bitter are spatially separated on the surface of the tongue b) are synonymous with taste buds c) are a type of chemoreceptors d) are innervated by afferents in the facial, trigeminal and glossopharyngeal nerves e) all of the above

e) all of the above

38. Light from an object to the right of the visual axis: a) impinges on the retina in the right eye to the right of the fovea b) impinges on the retina in the left eye to the left of the fovea c) generates impulses which produce conscious sensation in the frontal lobe eye fields d) forms an inverted image on the retina e) b, and d

e) b, and d

42. The receptor cells serving taste: a) are confined to the tongue b) are stimulated when chemicals diffuse through the overlying epithelium to reach them c) are primary sensory neurones d) are histologically different for the four primary taste modalities e) for sweetness are more common at the tip than at the back of the tongue

e) for sweetness are more common at the tip than at the back of the tongue

25. Adaptation for vision in poor light is: a) complete after 2-3 minutes b) due mainly to dilatation of the pupil c) due to regeneration of rod but not cone pigments d) slower if red goggles are worn before entering the dark environment e) more effective for peripheral than for central vision

e) more effective for peripheral than for central vision

36. The hair cells in the semicircular canals are stimulated by: a) movement of perilymph b) linear acceleration c) rotation at constant velocity d) gravity e) movement of endolymph relative to hair cells

e) movement of endolymph relative to hair cells

13. These receptors react to foods treated with monosodium glutamate: a) salt b) sour c) bitter d) sweet e) umami

e) umami

52. Which of these neurotransmitters is primarily responsible for natural pain relief in the body? a) NE b) substance P c) dopamine d) serotonin e) β-endorphins

e) β-endorphins

50. Local application of atropine to the eye causes: а) dilation of the pupil and reduced drainage of aqueous humour b) the near-point for clear vision to move closer to the eye c) inability to focus on objects at infinity d) dilation of the pupil and increased drainage of aqueous humour e) difficulty in looking upwards

а) dilation of the pupil and reduced drainage of aqueous humour