Neurophysiology Exam PDF January 25, 2010

Name__________________ Physiology 625/725 Neurophysiology Exam January 25, 2010 Choose the best answer _C_1. The excitatory postsynaptic potential (EPSP) phenomenon results from which of the following actions? a. b. c. d. the simultaneous opening of sodium and chloride channels the opening of potas...

Name__________________ Physiology 625/725 Neurophysiology Exam January 25, 2010 Choose the best answer _C_1. The excitatory postsynaptic potential (EPSP) phenomenon results from which of the following actions? a. b. c. d. the simultaneous opening of sodium and chloride channels the opening of potassium channels the opening of sodium channels the opening of chloride channels __A 2. The inhibitory postsynaptic potential (IPSP) phenomenon results from which of the following actions? a. b. c. d. the opening of potassium channels the opening of sodium channels the opening of voltage gated sodium channels the opening of voltage gated calcium channels _C_3. Transmission of the electrical signal from the dendrites of a neuron to the cell body of the neuron occurs by which of the following mechanisms? a. b. c. d. _B_4. short circuit current flow an action potential electrotonic conduction capacitive discharge Which of the following locations in the nervous systems contains the neuronal circuit for walking? a. b. c. d. the medulla the spinal cord the thalamus the cerebellum __C 5. Hypoventilation causes the blood to become more acidic. A lower blood pH usually increases neuronal activity. a. b. c. d. both statements are correct both statements are incorrect the first statement is correct, the second statement is not correct the first statement is not correct, the second statement is correct _D_6. Of the nerve fiber types listed below, which has the slowest speed of transmission of the action potential? a. b. c. d. Type A fibers Type A fibers Type A fibers Type c fibers __A 7. As the receptor potential of a receptor increases (becomes less negative), the number of action potentials generated in the axon attached to that receptor will exhibit which of the following responses? a. the number of action potentials will increase proportionally as long as the receptor potential is above the threshold for activation b. the number of action potentials will decrease as long as the receptor potential is above the threshold for activation c. the number of action potentials will remain constant once the threshold for activation is reached d. the number of action potentials will be constant and will be independent of further changes in the receptor potential Use this figure to answer question number 8. A B C _B__8. The figure above represents the response of a sensory receptor to a stimulus. Which sensory receptor has the slowest rate of adaptation to the stimulus? a. b. c. d. A B C none of the above represent a slowly adapting receptor __A_9. Which of the following nerve fiber types has the fastest rate of transmission of action potentials? a. b. c. d. type A type A type C type A __A_10. Gradations in signal intensity can be achieved by increasing the number of receptors being stimulated; this is referred to as spatial summation. Gradations in signal intensity can be achieved by increasing the rate of firing of a limited number of receptors; this is referred to as temporal summation. a. b. c. d. both statements are true both statements are false the first statement is true, the second is false the first statement is false, the second is true Use the following information to answer questions 11-14 An individual not wearing a seat belt was involved in a motor vehicle collision. The unrestrained individual was ejected from the vehicle and sustained a neck injury that transected (cut) one half of their spinal column in the anterior to posterior orientation as indicated in the figure below (hash marks indicate transected area) at the level of C-6 (the neck) on the left side of the spinal cord. This patient cannot move their left arm or leg but can move their right arm and leg. __A_11. Upon physical examination, which of the following sensory deficits would you expect to see in this patient? a. fine touch would be absent on the left side of their body b.fine touch would be absent on the right side of their body c. fine touch would be absent on both sides of their body d.fine touch would be enhanced on the left side. __A_12. Upon physical examination, which of the following sensations would you discover to remain intact in this patient? a. b. c. d. pain and temperature on the left side of the body pain and temperature on the right side of the body pain and temperature on both sides of the body. pain and temperature would only be present in the left leg _A__13. On which side of this patient would you expect the sensation of vibration to be absent? a. b. c. d. the left side of the body the right side of the body vibration sensation would be absent on both sides of the body in this patient vibration sensation would be present on the left side and absent on the right side of the body in this patient _B__14. On which side of this patient would the position sensation (proprioception) be present? a. b. c. d. the left side of this patient the right side of this patient position sensation would not be affected in this patient both sides of this patient _A__ 15. Which of the following statement/s concerning the neuronal pathways for the transmission of sensory information (dorsal column-medial lemniscal system and the anterolateral spinothalamic tract) is/are correct? a. decussation (crossing over to the opposite side) occurs following the first synaptic connection b. there are three synaptic connections along the sensory pathways from the periphery to the primary somatosensory cortex c. sensory neurons enter the spinal cord via the ventral or anterior roots of the spinal nerves d. all of the above are correct _B__16. The sensation of slow pain is transmitted in which of the following nerve tracts? a. b. c. d. the dorsal column system the paleospinothalamic tract the neospinothalamic tract the corticospinal tract _C__17. Neurons whose cell bodies are located in the nucleus raphe magnus and are involved in the endogenous pain suppression pathway synapse and release serotonin in which area of the nervous system? a. b. c. d. the periaqueductal gray area the periventricular area of the hypothalamus the dorsal horn of the spinal cord the ventral horn of the spinal cord _A__18. Which one of the following neurotransmitters is released by neurons of the periaqueductal gray area of the nervous system as they make connections with the neurons of the nucleus raphe magnus? a. b. c. d. enkephalin dopamine acetylcholine serotonin _C__19. Pain from the colon is referred to the lower abdominal area below the umbilicus. Pain from the ureter is referred to the lower back. a. b. c. d. both statements are true both statements are false the first statement is true, the second is false the first statement is false, the second is true _B__20. Hyperopia is a condition in which the refractive surfaces of the eye (cornea and lens) bring the light rays to a focal point behind the retina, it can be corrected by a concave lens because this lens will converge the light rays and bring them to a focal point on the retina. a. b. c. d. both the statement and the reason are correct and related the statement is correct, but the reason is not the statement is not correct, but the reason is correct neither the statement nor the reason is correct _B__21. Damage to the cornea is a serious condition because the cornea is responsible for focusing the visual image on the retina. a. b. c. d. both the statement and the reason are correct and related the statement is correct, but the reason is not the statement is not correct, but the reason is correct neither the statement nor the reason is correct _A__ 22. All of the conditions below can be corrected by placing a lens system in front of the eye EXCEPT one. Which one is the EXCEPTION? a. b. c. d. cataracts hyperopia presbyopia myopia _B__ 23. During exposure of the photoreceptor to light, all of the following increase EXCEPT one. Which one is the EXCEPTION? a. b. c. d. metarhodopsin II c-GMP transducin c-GMP phosphodiesterase _B__24. Which of the following substances is responsible for keeping the sodium channels open in the outer segments of the rods and cones in low light conditions? a. b. c. d. metarhodopsin II cyclic GMP cyclic AMP melanin _D_ 25. Which of the following statements is/are true? a. an individual rod can respond to all wavelengths of light b. in conditions of normal daylight, the level of cGMP is not sufficient to keep open the sodium channels in the outer segment of the photoreceptors c. light causes the outer segments of the photoreceptors to hyperpolarize d. all of the above _D__26. Which of the following makes a direct connection with the round window? a. b. c. d. the stapes the malleus the incus none of the above __D_ 27. Damage to the inner hair cells of the organ of Corti located from the midpoint of the basement membrane to the helicotrema will most likely result in which of the following? a. b. c. d. a loss of the ability to perceive high frequency sounds a loss of the ability to taste all but the bitter taste sensation a loss of the ability to appreciate the floral scent a loss of the ability to perceive mid and low frequency sounds __C_28. Which of the following is correct? a. the amplitude of sound is determined by the position of displacement along the basement membrane of the cochlea b. the outer hair cells of the organ of Corti transduce the sound signal c. amplitude of sound is determined by the amount of displacement of the basement membrane of the cochlea d. frequency of sound is determined by the amount of displacement along the basement membrane of the cochlea _D__29. Which chemical properties must be at least partially present in a substance for it to be perceived by the olfactory system as an odor? a. b. c. d. it must be water soluble it must be lipid soluble it must be volatile all of the above __A_30. The bitter taste sensation is the result of stimulation of the appropriate taste receptor by? a. b. c. d. long chain organic substances containing nitrogen. ionized salts. hydrogen ions. complex organic molecules. __D_31. Damage to the facial nerve would impair which of the following sensations? a. b. c. d. taste sensation on the posterior third of the tongue the sense of smell the taste sensation on the posterior aspects of the pharynx the taste sensation on the anterior portion of the tongue A or _C _ 32. The rapid adaptation of the taste sensation is thought to be a phenomenon that is related to a. b. c. d. the taste buds themselves the area from which the taste buds are located on the tongue a mechanism in the central nervous system the type of taste sensation _A__33. Which of the following is paired correctly? a. b. c. d. the dynamic response of the muscle spindle – the rate of muscle stretch the static response of muscle spindle – the rate of muscle stretch golgi tendon organ – rate of muscle stretch alpha motor neuron – intrafusal fiber __D_34. All of the activities listed below will cause muscle contraction either directly or reflexly EXCEPT one. Which one is the EXCEPTION? a. b. c. d. stimulation of a gamma motor neuron stretch of the muscle spindle receptor stimulation of an alpha motor neuron stimulation of the Golgi tendon organ _A__35. The patellar reflex (knee jerk reflex) is initiated by striking the patellar tendon with a rubber hammer. Which of the following is the correct sequence of events in this reflex? a. stretch of the muscle spindle receptor, activation of type 1a sensory fibers, activation of the alpha motor neuron, contraction of the quadriceps muscle b. stretch of the Golgi tendon organ, activation of type 1b sensory fibers, activation of the alpha motor neuron, contraction of the quadriceps muscle c. stimulation of the gamma motor neuron, stretch of the muscle spindle receptor, activation of the alpha motor neuron, contraction of the quadriceps muscle d. activation of a pain receptor, activation of the alpha motor neuron, contraction of the quadriceps muscle Questions 36-43. Match the neurological structures below with the correct function or neurological deficit: A. B. C. D. E. F. G. H. Caudate Nucleus Wernike’s Area Hippocampus Thalamus Cerebellum Subtantia Nigra Subthalamus Nucleus Raphe Magnus __B__36. Responsible for verbal and symbolic intelligence on the dominant hemisphere of the brain __E__37. Responsible for timing and sequencing of motion __G__38. Damage to this area results in the condition called hemiballismus __C__39. Responsible for the creation of new memories __A__40. Damage to this structure results in the condition called chorea __F__41. Pathology of this area is associated with Parkinson’s disease __D__42. Area of brain responsible for recalling stored memories __H__43. This area is part of the pain suppression pathway __B__44. Which of the following symptoms is characteristic of cerebellar dysfunction? a. b. c. d. hemiballismus ataxia athetosis rigidity and tremor __A_ 45. Nicotinic receptors are located in which of the following structures? a. b. c. d. in autonomic ganglia on parasympathetic effector cells on sympathetic effector cells on the ciliary muscle of the eye Bonus question. Please refer to the figure below to answer the bonus question A C B _B___46 . The figure above represents the response of a hair cell in the crista ampullaris of the semicircular canal to stimulation by rotation in a human subject. With the subject’s eyes closed, the subjective sensation of rotation will be absent at which point/s indicated by the letters A through C? a. point A b. point B c. point C d. points B and C