BIOL2010 Huaman A&P I -- Exam XX -- Form A

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1 BIOL2010 Huaman A&P I -- Exam XX -- Form A Name: 1. Axons A. have a distal portion that branches to form the presynaptic terminals. B. are numerous extensions from each neuron. C. do not have a trigger zone. D. contain the nucleus. E. do not have a resting membrane potential. 2. Voltage-gated sodium channels are sensitive to changes in the extracellular concentration of A. potassium ions. B. calcium ions. C. proteins. D. sodium ions. E. chloride ions. 3. Local hyperpolarization in a synapse is called a(an) A. gap junction potential. B. action potential. C. resting membrane potential. D. inhibitory postsynaptic potential. E. excitatory postsynaptic potential. 4. Which of the following brain areas serves as the major control center of the autonomic nervous system and endocrine system? A. midbrain B. thalamus C. brainstem D. pons E. hypothalamus 5. What do the cavities of the neural tube become in the adult brain? A. coelom B. auricles C. subarachnoid space D. ventricles 6. Depolarization of the nerve cell membrane occurs when there is a rapid influx (inflow) of A. chloride ions. B. proteins. C. potassium ions. D. calcium ions. E. sodium ions. 7. The motor (efferent) division of the peripheral nervous system A. transmits impulses from the CNS to skeletal muscle. B. has nerve cell bodies located in ganglia near the spinal cord and brain. C. is a division of the CNS. D. regulates the digestion of food. E. detects a stimulus.

2 8. Association fibers connect A. areas of the cerebral cortex with areas of the midbrain. B. the cerebrum with the spinal cord. C. areas of the cerebral cortex within the same hemisphere. D. one cerebral hemisphere to another. E. areas of the cerebral cortex with areas of the spinal cord. 9. The fact that the right side of the brain controls the left side of the body is explained by the A. need for contra-lateral control of body function. B. decussation of the pyramids in the medulla. C. division of the cerebellum into two hemispheres. D. division of the cerebrum into two hemispheres. E. brainstem being below the midbrain. 10. A stimulus either causes an action potential or it doesn't. This is called A. a relative refractory response. B. a graded response. C. a local response. D. a latent period response. E. an all-or-none response. 11. Which of the following cranial nerves is exclusively sensory? A. trigeminal (V) B. trochlear (IV) C. vestibulocochlear (VIII) D. hypoglossal (XII) E. facial (VI) 12. The sensory root of a spinal nerve is also referred to as A. ventral root. B. efferent root. C. dorsal root. D. anterior root. E. lateral root. 13. The ventral root of a spinal nerve contains A. a ganglion. B. only motor fibers. C. both sensory and motor fibers. D. only afferent fibers. E. only sensory fibers. 14. The sensory receptor of the stretch reflex is the A. muscle spindle. B. alpha motor neurons. C. dorsal root ganglion. D. Golgi tendon organ. E. collateral axon.

3 15. The primary somatic sensory or general sensory area is located in A. the precentral gyrus. B. Wernicke's gyrus. C. the prefrontal cortex. D. the postcentral gyrus. E. the prefrontal gyrus. 16. The lateral fissure separates the from the rest of the cerebrum. A. occipital lobe B. parietal lobe C. cerebellum D. temporal lobe E. frontal lobe 17. During the absolute refractory period, the cell A. reverses the direction of the action potential. B. responds to even weak stimuli. C. is insensitive to further stimulation. D. generates many local potentials. E. is very sensitive. 18. Cerebrospinal fluid fills the A. epidural space. B. subarachnoid space. C. None of these choices is correct. D. subdural space. E. dural sinuses. 19. When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to sodium ions, A. an excitatory postsynaptic potential (EPSP) will result. B. the sodium ions diffuse out of the cell. C. the membrane will be hyperpolarized. D. the membrane will become impermeable to potassium ions. E. more chloride ions will also diffuse into the cell. 20. Which of the following statements concerning the brainstem is true? A. Damage to the brainstem is usually fatal. B. The brainstem is responsible for higher level thinking skills. C. The brainstem consists of the medulla, pons, and cerebellum. D. The brainstem is a relay for sensory input. E. All twelve cranial nerves enter or exit from the brainstem. 21. The junction of a neuron with another cell is a/an A. effector. B. ganglion. C. synapse. D. receptor.

4 22. An IPSP is inhibitory because it A. reduces the amount of neurotransmitter released by the presynaptic terminal. B. depolarizes the postsynaptic membrane. C. hyperpolarizes the postsynaptic membrane. D. changes the threshold of the neuron. E. prevents Ca 2+ entry into the presynaptic terminal. 23. Which of the following events will lead to depolarization? A. an increase in Na+ ions in the extracellular fluid B. a decrease in K+ ions in the extracellular fluid C. an increase in K+ ions in the extracellular fluid D. an increase in the rate of diffusion of K+ ions from cells E. None of these events would cause depolarization. 24. The middle, thin, spider-like meninx is the A. arachnoid mater. B. pia mater. C. dura mater. D. ectomater. 25. There are enlargements of the spinal cord where nerves supplying the extremities enter and leave. A. two B. three C. five D. six E. four 26. Multiple sclerosis is a neurological disorder in which myelin sheaths in the CNS are destroyed. Which of the following neuroglial cells is being damaged in multiple sclerosis? A. oligodendrocyte B. astrocyte C. microglial cell D. ependymal cell E. Schwann cells 27. Gap junctions are functional synapses. A. electrical B. intracellular C. neuromuscular D. potential E. chemical 28. Reflexes function in A. keeping the body from falling. B. maintaining blood pressure. C. All of these choices are correct. D. maintaining blood CO 2 levels. E. removing the body from painful stimuli.

5 29. Dentists anesthetize a portion of the nerve to stop pain impulses from the teeth. A. trigeminal B. abducens C. facial D. glossopharyngeal E. hypoglossal 30. White matter is composed of A. bundles of myelinated axons. B. ganglial sheaths. C. collections of nerve cell bodies. D. collections of unmyelinated axons. E. bundles containing both myelinated axons and nerve cell bodies. 31. The cerebral medulla A. is the outer layer of the cerebrum. B. is another name for the basal nuclei. C. has the same function as the medulla oblongata. D. consists of many nerve tracts of white matter beneath the cerebral cortex. E. is the gray matter on the cerebrum's surface. 32. The abducens nerves A. are involved in eye movement. B. slow the heart rate. C. control size of the pupil. D. transmit pain impulses from the teeth. E. dilate blood vessels in the skin. 33. The speed of an action potential depends upon A. the diameter of the axon. B. thickness of the myelin sheath. C. All of the choices are correct. D. whether an axon is myelinated or not myelinated. 34. Synaptic vesicles contain neurotransmitters and are present in the A. trigger zone. B. presynaptic terminals. C. axolemma. D. cell body. E. dendrites. 35. Mr. Miller has been hospitalized for the flu. The flu virus increases membrane permeability to potassium. You would expect his cells to A. hypopolarize. B. repolarize. C. isopolarize. D. hyperpolarize. E. depolarize.

6 36. Dermatomal maps are important clinically because they A. locate the position of cranial nerves. B. can be used to help locate nerve damage. C. can be used to check for motor function. D. can be used to detect cranial nerve damage. E. indicate what muscles are innervated by each spinal nerve. 37. The spinal cord A. stores reflexive memory. B. controls the reticular activating system. C. links the peripheral nervous system to the brain. D. is characterized by conscious activity. E. forms memory engrams. 38. Microglia A. are part of the choroid plexus. B. produce cerebrospinal fluid. C. are part of the blood-brain barrier. D. are phagocytic cells in the CNS. E. form myelin sheaths. 39. Gaps or interruptions in the myelin sheath are called A. gap junctions. B. tight junctions. C. nodes of Ranvier. D. internodes. E. neurofilaments. 40. The nervous system A. maintains homeostasis. B. interprets or assesses information. C. All of these choices are correct. D. monitors internal and external stimuli. E. transmits information in the form of action potentials. 41. The thickest of the meninges is the A. subarachnoid space. B. arachnoid mater. C. subdural space. D. dura mater. E. pia mater. 42. The reflex that prevents excessive tension in a muscle is the A. crossed extensor reflex. B. reciprocal reflex. C. stretch reflex. D. Golgi tendon reflex. E. withdrawal reflex.

7 43. Gray matter has little myelination, whereas white matter has abundant myelination. A. True B. False 44. Which two portions of the brain are involved in controlling respiration? A. pons, medulla oblongata B. cerebrum, hypothalamus C. pons, thalamus D. pons, hypothalamus E. medulla oblongata, cerebral peduncles 45. Which of the following is NOT a function of the cerebellum? A. control the heart rate B. help in the maintenance of muscle tone C. control of posture, locomotion, and fine motor coordination. D. coordinate control of voluntary movements E. control skeletal muscles to maintain balance 46. Which of the following is true? A. The resting plasma membrane is more permeable to Na+ than K+. B. The resting membrane potential never reaches an equilibrium point. C. The purpose of the sodium-potassium exchange pump is to create an equilibrium of ion concentrations. D. The resting membrane potential is proportional to the tendency for K+ to diffuse out of the cell. E. Negatively charged Cl- ions are attracted by negative charges in the cell. 47. Arrange the events of synaptic transmission in correct sequence. (1) sodium ions diffuse into the cell and cause a local potential (2) neurotransmitter binds with receptor on postsynaptic cell (3) neurotransmitter diffuses across the synaptic cleft (4) membrane permeability to sodium ions on postsynaptic cell increases (5) action potential causes release of neurotransmitter A. 5, 3, 4, 1, 2 B. 5, 4, 3, 2, 1 C. 5, 2, 3, 4, 1 D. 5, 3, 2, 4, 1 E. 5, 2, 3, 1, A change in resting membrane potential confined to a small area is called a(n) A. resting membrane potential. B. summated potential. C. local potential. D. afterpotential. E. action potential. 49. In some cells, an afterpotential occurs because A. the sodium ions continue to enter the cell after depolarization is finished. B. the extracellular Na+ ion concentration is reduced. C. there is prolonged, elevated permeability to potassium during repolarization. D. the permeability to sodium continues longer than necessary. E. the sodium-potassium pump is actively exchanging ions across the membrane.

8 50. Receptor molecules A. determine whether a neurotransmitter will be excitatory or inhibitory. B. are always lipids. C. attach to the synaptic cleft. D. are not attached to ligand-gated channels. E. are nonspecific. 51. The adaptive significance of the crossed extensor reflex when a person steps on a tack is to A. increase the rate at which withdrawal of the limb occurs. B. reduce the pain sensations. C. slow the rate of removal of the foot from the tack. D. prevent the person from falling down. E. remove the foot from the tack. 52. Which portion of the brainstem is continuous with the spinal cord? A. thalamus B. pons C. midbrain D. cerebral peduncles E. medulla oblongata 53. Place the following parts of a reflex arc in the correct order beginning with the sensory receptor. (1) motor neuron (2) interneuron (3) effector (4) sensory neuron (5) sensory receptor A. 5, 4, 2, 1, 3 B. 5, 4, 3, 2, 1 C. 5, 3, 2, 4, 1 D. 5, 1, 2, 3, 4 E. 5, 2, 3, 4, The motor neurons responsible for making a fist are A. tripolar. B. bipolar. C. multipolar. D. None of these choices are correct. E. pseudo-unipolar. 55. The central sulcus separates the A. parietal and occipital lobes. B. occipital and temporal lobes. C. temporal and frontal lobes. D. frontal and parietal lobes. E. two parietal lobes.

9 56. Arrange the following in order from the diencephalon downward. (1) spinal cord (2) midbrain (3) medulla (4) pons A. 1, 2, 3, 4 B. 4, 1, 3, 2 C. 2, 4, 3, 1 D. 4, 2, 3, 1 E. 3, 2, 4, When repolarization of a neuron is complete, the A. neuron dies. B. cell no longer has a potential difference across its membrane. C. neuron regenerates. D. original polarity of the neuron is restored. E. neuron is no longer excitable. 58. Which of the following situations occurs in electrically excitable cells? A. Depolarization causes voltage-gated sodium ion channels to open. B. Proteins tend to diffuse out of the cell. C. The sodium-potassium exchange pump moves sodium into the cell. D. When Na+ ion channels open, K+ ion channels close. E. Ligand-gated sodium ion channels are opened by high extracellular calcium levels. 59. Suppose both excitatory and inhibitory neurons synapse with a single postsynaptic neuron. What determines if an action potential is initiated in the postsynaptic neuron? A. whether the neuron is myelinated or non-myelinated B. the number of EPSPs in relation to the number of IPSPs C. the size of the neuron involved D. This situation is not possible in humans. E. the kind of neuron involved 60. Which of the following statements regarding neuroglia is false? A. Neuroglia serve as the major supporting tissue in the CNS. B. Neuroglia form myelin sheaths around some axons. C. Neuroglia produce cerebrospinal fluid. D. Neuroglia produce action potentials for skeletal muscles. E. Neuroglia form part of the blood-brain barrier. 61. If the charge difference across the plasma membrane is decreased, A. the change is called hyperpolarization. B. the potential difference across the plasma membrane does not change. C. negative proteins can leave the cell. D. the membrane potential is more positive. E. the membrane potential is more negative. 62. What is found in the dorsal root ganglion? A. The cell bodies of pseudo-unipolar sensory neurons. B. The cell bodies of multipolar interneurons. C. The cell bodies of multipolar motor neurons. D. The cell bodies of bipolar sensory neurons.

10 63. Schwann cells differ from oligodendrocytes in which of the following ways? A. Schwann cells form sheaths around several axons, while oligodendrocytes form sheaths around only one axon. B. Oligodendrocytes are only found in the PNS; Schwann cells are only found in the CNS. C. Schwann cells form myelin; oligodendrocytes do not. D. Schwann cells form a myelin sheath around a portion of only one axon, while oligodendrocytes can surround portions of several axons. E. None of these choices are true differences. 64. The cerebral aqueduct connects A. connects the lateral ventricles to the third ventricle. B. connects the fourth ventricle to the subarachnoid space. C. the third ventricle to the fourth ventricle. D. the two lateral ventricles. 65. Digestion of food is regulated by the A. sympathetic division of the ANS. B. None of these choices are correct. C. somatic nervous system. D. sensory division. E. parasympathetic division of the ANS. 66. The plasma membrane of a neuron is more permeable to potassium ions because A. protein molecules cannot exit through the cell membrane. B. calcium ions block Na+ and Cl- channels. C. of its positive electrical charge. D. there are more leak ion channels for K+ than Na+. E. there are more leak ion channels for Na+ than K What is the large C-shaped mass of white matter that consists of nerve fibers that connect the two cerebral hemispheres? A. gyrus B. vermis C. corpus callosum D. intermediate mass E. infundibulum 68. The sensory (afferent) division of the peripheral nervous system A. conveys action potentials to the CNS. B. transmits action potentials to sensory organs. C. does not involve sensory receptors. D. stimulates muscle contractions. E. stimulates glands to release hormones. 69. Most sensory input that ascends through the spinal cord and brainstem projects to the A. subthalamus. B. pineal gland. C. hypothalamus. D. mammillary bodies. E. thalamus.

11 70. The gray matter on the outer surface of the cerebrum is called the A. arbor vitae. B. cortex. C. cerebral medulla. D. reticular formation. E. pia mater. 71. The cerebral gyri increase A. the size of the thalamic nuclei. B. memory assimilation time. C. the surface area of the cortex. D. speech ability. E. volume of the brain. 72. Protein synthesis in neurons occurs in A. cell bodies or soma. B. dendrites. C. axons. D. terminal boutons. E. node of Ranvier. 73. Sensory neurons carrying action potentials from pain receptors synapse within the spinal cord with interneurons. These interneurons synapse with motor neurons leading back to an effector and ascending neurons that carry action potentials toward the brain. This is an example of a(n) pathway. A. sensory B. bifurcated C. reverberating D. divergent E. convergent 74. Each voltage-gated Na+ ion channel has two voltage sensitive gates: an activation gate and an inactivation gate. Which of the following would occur during depolarization? A. None of these events occurs during depolarization. B. Both activation and inactivation gates are open. C. Both activation and inactivation gates are closed. D. Activation gates are open; inactivation gates are closed. E. Activation gates are closed; inactivation gates are open. 75. The part of the brain that connects the medulla to the midbrain is the A. thalamus. B. pons. C. cerebral peduncle. D. cerebellum. E. hypothalamus.

12 76. Which of the following statements accurately describe events that occur as a result of a local potential reaching threshold? A. Inactivation gates of Na+ ion channels begin to open. B. K+ ion channels begin to close. C. Inactivation gates of Na+ ion channels begin to open and a positive feedback cycle develops in which depolarization causes activation gates of Na+ ion channels to open. D. Activation gates of Na+ ion channels begin to close. E. A positive feedback cycle develops in which depolarization causes activation gates of Na+ ion channels to open. 77. Which of the following activities would stimulate the reticular formation? A. a long lecture in a darkened auditorium B. a warm bath C. getting a back rub D. eating a big meal E. a clock radio coming on in the morning 78. What is found the lateral gray horns of the spinal cord? A. The cell bodies of somatic sensory neurons. B. The cell bodies of sensory neurons. C. The cell bodies of autonomic motor neurons. D. The cell bodies of somatic motor neurons. 79. An action potential A. occurs when the local potential reaches threshold level. B. is an example of negative feedback. C. has no repolarization phase. D. propagates across the plasma membrane in a decremental fashion. E. cannot transmit information. 80. The central nervous system includes the A. spinal cord. B. sensory receptors. C. cranial nerves. D. spinal nerves. E. ganglia.