1. An increase in refractive power is produced by contraction of thea. Irisb. Ciliary bodyc. Suspensory ligamentsd. Extraocular musclese. Pupil (B)

2. The primary function of the bones of the middle ear is toa. Amplify the sound stimulusb. Filter high-frequency sounds from the sound stimulusc. Enable the direction of a sound stimulus to be detectedd. Enhance the ability to distinguish different sound frequenciese. Protect the ear from damage (A)

3. During a voluntary movement, the Golgi tendon organ provides thecentral nervous system with information abouta. The length of the muscle being movedb. The velocity of the movementc. The blood flow to the muscle being movedd. The tension developed by the muscle being movede. The change in joint angle produced by the movement (D)

4. Repetitive stimulation of a skeletal muscle fiber will cause an increasein contractile strength because repetitive stimulation causes an increase ina. The duration of cross-bridge cyclingb. The concentration of calcium in the myoplasmc. The magnitude of the end-plate potentiald. The number of muscle myofibrils generating tensione. The velocity of muscle contraction (A)

5. Free nerve endings contain receptors that encode the sensation ofa. Fine touchb. Vibrationc. Pressured. Temperaturee. Muscle length (D)

6. An aphasia is most likely to be associated with a lesion ofa. The hippocampusb. The temporal lobec. The parietal lobed. The limbic systeme. The reticular activating system (B)

7. Depolarization of the hair cells in the cochlea is caused primarily bythe flow of

a. K+ into the hair cellb. Na+ into the hair cellc. Cl- out of the hair celld. Ca2+ into the hair celle. Mg2+ into the hair cell (A)

8. The most important role of the gamma motoneurons is toa. Stimulate skeletal muscle fibers to contractb. Maintain Ia afferent activity during contraction of musclec. Generate activity in Ib afferent fibersd. Detect the length of resting skeletal musclee. Prevent muscles from producing too much force (B)

9. Each of the figures in the diagram below illustrates a train of actionpotentials in response to a sudden limb movement. The sensory neuronencoding the velocity of the limb movement is illustrated by which figure?a. Ab. Bc. Cd. De. E (B)

10. Which of the following receptors is responsible for measuring theintensity of a steady pressure on the skin surface?a. Pacinian corpuscleb. Ruffini endingc. Merkel’s diskd. Meissner’s corpusclee. Krause ending (B)

11. The middle cerebellar peduncle contains afferent fibers conveyed inwhich of the following tracts?a. Dorsal spinocerebellarb. Ventral spinocerebellarc. Tectocerebellard. Pontocerebellare. Vestibulocerebellar (D)

12. The precentral gyrus and corticospinal tract are essential fora. Visionb. Olfactionc. Auditory identificationd. Kinesthesiae. Voluntary movement (E)

13. A patient who presents with an intention tremor, “past-pointing,”

and a “drunken” gait might be expected to have a lesion involving thea. Cerebellumb. Medullac. Cortical motor stripd. Basal gangliae. Eighth cranial nerve (A)

14. The otolith organs (utricle and saccule) are responsible fora. Producing the vestibular-ocular reflexb. Detecting the position of the head in spacec. Producing rotary nystagmusd. Detecting angular acceleratione. Producing the stretch reflex (B)

15. Which one of the reactions in the retinal rods is caused directly bythe absorption of light energy?a. Dissociation of scotopsin and metarhodopsinb. Decomposition of scotopsinc. Transformation of 11-cis retinal to all-trans retinald. Transformation of metarhodopsin to lumirhodopsine. Transformation of vitamin A to retinene (C)

16. Which of the following statements about the cerebrospinal fluid(CSF) is true?a. It is absorbed by the choroid plexusb. Its absorption is independent of CSF pressurec. It circulates in the epidural spaced. It has a lower glucose concentration than plasmae. It has a higher protein concentration than plasma (D)

17. When a person slowly rotates toward the right,a. The stereocilia on the hair cells in the right horizontal semicircular canal bendaway from the kinociliumb. Both the left and right eyes deviate toward the leftc. The hair cells in the left horizontal semicircular canal become depolarizedd. The visual image on the retina becomes unfocusede. The endolymph in the left and right horizontal semicircular canals moves in (B)opposite directions

18. During a normal voluntary movementa. Large muscle fibers are recruited before small muscle fibersb. Fast muscle fibers are recruited before slow muscle fibersc. Weak muscle fibers are recruited before strong muscle fibersd. Poorly perfused muscle fibers are recruited before richly perfused muscle fiberse. Anaerobic fibers are recruited before aerobic fibers (C)

19. Correct statements regarding rapid eye movement (REM) sleepinclude which of the following?a. It is the first state of sleep entered when a person falls asleepb. It is accompanied by loss of skeletal muscle tonec. It is characterized by a slow but steady heart rated. It occurs more often in adults than in childrene. It lasts longer than periods of slow-wave sleep (B)

20. When emmetropic persons become presbyopic, theira. Visual acuity increasesb. Near point increasesc. Far point decreasesd. Total refractive power increasese. Ability to see distant objects decreases (B)

21. When light strikes the eye there is an increase ina. The activity of the transducinb. The amount of transmitter released from the photoreceptorsc. The concentration of all-trans retinal within the photoreceptorsd. The concentration of calcium within the photoreceptorse. The activity of guanylyl cyclase (A)

22. Spasticity can be caused by sectioninga. The corticospinal fibersb. The vestibulospinal fibersc. The Ia afferent fibersd. The corticoreticular fiberse. The reticulospinal fibers (D)

23. Activation of transducin by light activates an enzyme whicha. Hydrolyzes cGMPb. Increases the dark currentc. Activates adenylyl cyclased. Releases calcium from intracellular storese. Depolarizes the membrane (A)

24. If nystagmus is a prominent symptom of a cerebellar lesion, thelesion is withina. The dentate nucleusb. The flocculonodular lobec. The lateral cerebellumd. The cerebrocerebellar cortexe. The superior cerebellar peduncle (B)

25. The alpha rhythm appearing on an electroencephalogram has whichof the following characteristics?

a. It produces 20 to 30 waves per secondb. It disappears when a patient’s eyes openc. It is replaced by slower, larger waves during REM sleepd. It represents activity that is most pronounced in the frontal region of the braine. It is associated with deep sleep (B)

Questions 26-27The image distance of a normal relaxed eye is indicated in the diagrambelow.26. The focal length of the eye isa. 14 mmb. 15 mmc. 17 mmd. 19 mme. 21 mm (A)

27. If an object is placed 25 cm away from the eye, the image will befocused on the retina if the refractive power of the eye is increased toa. 64 dioptersb. 68 dioptersc. 70 dioptersd. 72 diopterse. 75 diopters (E)

28. Tapping the patella tendon elicits a reflex contraction of the quadricepsmuscle. During the contraction of the quadriceps muscle,a. The Ib afferents from the Golgi tendon organ increase their rate of firingb. The Ia afferents from the muscle spindle increase their rate of firingc. The alpha motoneurons innervating the extrafusal muscle fibers decrease theirrate of firingd. The gamma motoneurons innervating the intrafusal muscle fibers increase theirrate of firinge. The alpha motoneurons to the antagonistic muscles increase their rate of firing (A)

29. Increased activity of the sympathetic nervous system causesa. Penile erectionb. Pupillary constrictionc. Accommodation for near visiond. Bronchiolar dilatione. Gallbladder emptying (D)

30. Norepinephrine will cause contraction of the smooth muscle in thea. Bronchiolesb. Pupilsc. Intestined. Arterioles

e. Ciliary body (D)

31. If the threshold for hearing increases 1000 times, the hearing loss isa. 20 decibelsb. 30 decibelsc. 40 decibelsd. 50 decibelse. 60 decibels (E)

32. If a patient is unable to hear high-frequency sounds, the damage tothe basilar membrane is closest to thea. Oval windowb. Helicotremac. Stria vascularisd. Modioluse. Spiral ganglion (A)

33. An abnormal Babinski reflex indicates damage to thea. Spinal cordb. Brainstemc. Cerebellumd. Basal gangliae. Pyramids (E)

34. Which of the following hypothalamic nuclei is responsible for controllingthe normal circadian rhythm?a. Paraventricular nucleusb. Ventromedial nucleusc. Arcuate nucleusd. Lateral nucleuse. Suprachiasmatic nucleus (E)

35. Presynaptic inhibition in the central nervous system affects the firingrate of alpha motoneurons bya. Increasing the chloride permeability of the presynaptic nerve endingb. Decreasing the potassium permeability of the alpha motoneuronc. Decreasing the frequency of action potentials by the presynaptic nerve endingd. Increasing (hyperpolarizing) the membrane potential of the alpha motoneurone. Increasing the amount of the neurotransmitter released by the presynapticnerve ending (A)

36. Which one of the following events accompanies the rapid voluntaryflexion of the arm?a. An increase in the activity of the Ia afferent fibers from the biceps (the agonist)b. A decrease in the activity of the Ib afferent fibers from the biceps (the agonist)c. An increase in the activity of the Ia afferent fibers from the triceps (the antagonist)

d. A decrease in the activity of the Ib afferent fibers from the triceps (the antagonist)e. An increase in the activity of the alpha motoneurons to the triceps (the antagonist) (C)

37. The sympathetic response in a “fight or flight” reaction causes adecrease ina. The arterial blood pressureb. The diameter of the pupilc. The resistance of the airwaysd. The blood glucose concentratione. The heart rate (C)

38. Which one of the optic field defects listed in the following diagram isproduced by a pituitary gland tumor?a. Ab. Bc. Cd. D (B)

39. Which one of the following visual lesions will produce extensive lossof peripheral vision in the left visual fields of both eyes?a. A lesion of the left lateral geniculateb. Section of the left optic nervec. A lesion of the right visual cortexd. Removal of the right lense. Section of the left optic tract (C)

40. The pain produced by ischemia is poorly localized and throbbingwhile pain from a needle stick is well localized and sharp. Which of the followingcomparisons of ischemic and needle stick pain is correct?a. Ischemic pain sensory fibers are classified as A delta (AΔ) sensory fibersb. Ischemic pain is produced by overstimulating somatic touch receptorsc. Ischemic pain is transmitted to the brain through the neospinothalamic tractd. Ischemic pain receptors quickly adapt to a painful stimuluse. Ischemic pain sensory fibers terminate within the substantia gelatinosa of thespinal cord (E)

41. Which one of the following hypothalamic nuclei is responsible forthe detection of the core body temperature?a. The lateral hypothalamusb. The arcuate nucleusc. The posterior nucleusd. The paraventricular nucleuse. The anterior hypothalamus (E)

42. In which one of the following sensory systems does stimulationcause the receptor cell to hyperpolarize?

a. Visionb. Hearingc. Tasted. Touche. Smell (A)

43. The Klüver-Bucy syndrome is characterized by decreased emotionalexpression, loss of fear, excessive oral behavior, and increase in sexualactivity. These characteristics of the Klüver-Bucy syndrome are producedby bilateral lesions of thea. Hippocampusb. Amygdalac. Ventral hypothalamusd. Corpus callosume. Cingulate gyrus (B)