AutoRecovery save of marieb-hap11-ch11-testbank.docx

Human Anatomy & Physiology, 11e Digital Update (Marieb) Chapter 11 Fundamentals of the Nervous System and Nervous Tissue 11.3 Multiple Choice Questions 1) Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which divi...

Human Anatomy & Physiology, 11e Digital Update (Marieb) Chapter 11 Fundamentals of the Nervous System and Nervous Tissue 11.3 Multiple Choice Questions 1) Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division Answer: D 2) Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division Answer: A 3) Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division Answer: B 4) Cranial nerve II, the optic nerve sends nerve impulses to the brain carrying information about the things we see. These nerve fibers most likely belong to which division of the nervous system? A) sensory (afferent) division B) somatic nervous system C) sympathetic division D) parasympathetic division Answer: A 5) The concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for this? A) satellite cells B) astrocytes C) Schwann cells D) oligodendrocytes Answer: B 6) Some nerve fibers of the peripheral nervous system have the ability to regenerate after damage has occurred. Which of the following cells is most responsible for aiding in this regulation? A) satellite cells B) astrocytes C) Schwann cells D) oligodendrocytes Answer: C 7) It is important for newly developed neurons to form synapses with other neurons. Which cells are most responsible for guiding the formation of these particular junctions? A) satellite cells B) astrocytes C) Schwann cells D) microglial cells Answer: B 8) Meningitis can be caused by infection of the central nervous system by bacteria. Which cells would be most responsible for removing the infection? A) microglia B) satellite cells C) Schwann cells D) oligodendrocytes Answer: A 9) Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensive network of rough endoplasmic reticulum and many clusters of ribosomes. These cellular features indicate all of the following EXCEPT ________. A) neurons must meet a high demand for ATP B) neurons have a relatively high consumption of oxygen C) neurons have stable, relatively unchanging internal environments D) neurons produce many proteins Answer: C 10) An action potential is regarded as an example of a positive feedback. Which of the following examples below best illustrates the positive feedback aspect of an action potential? A) Voltage gated potassium ion channels open slowly and remain open long enough to cause hyperpolarization. B) A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels. C) The sodium potassium pump consistently moves ions as long as ATP is available, and regardless of membrane potential changes. D) Potassium permeability is about 25 times greater than sodium ions. Answer: B 11) The depolarization phase of an action potential is punctuated by the closing of inactivation gates in the voltage gated sodium ion channels. All of the following are consequences of this inactivation except one. Choose the statement below that is not a consequence of the closing of inactivating gates. A) This allows for the one way transmission of action potential down the axon. B) This stops the depolarization of the axon membrane. C) This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell. D) This limits the frequency of action potentials down the axon. Answer: C 12) During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that ________. A) the membrane is now impermeable to all ions B) the inactivation gates on voltage gated sodium ion channels are closed C) the sodium potassium pump will stop working during relative refractory D) the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane Answer: D 13) If a postsynaptic neuron is stimulated to threshold by spatial summation this implies that ________. A) the postsynaptic cell has many synapses with many presynaptic neurons B) the postsynaptic cell has a lower than normal threshold C) the postsynaptic cell has many voltage gated ion channels D) the postsynaptic cell is slow to repolarize Answer: A 14) If a postsynaptic cell is stimulated to threshold by temporal summation this implies that ________. A) a presynaptic neuron is sending frequent EPSP B) the presynaptic neuron is sending frequent IPSP C) the postsynaptic cell is sending frequent action potential D) the postsynaptic cell can be influenced by only one presynaptic cell Answer: A 15) When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the postsynaptic cell? A) Chemically gated sodium channels will open. B) Chemically gated chloride channels will open. C) Chemically gated potassium channels will open. D) Chemically gated sodium channels will be closed. Answer: A 16) When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the postsynaptic cell? A) depolarization of the postsynaptic cell membrane B) hyperpolarization of the postsynaptic cell membrane C) opening of chemically gated sodium channels D) influx of positively charged ions into the postsynaptic cell Answer: B 17) The effect of acetylcholine can be stimulating or inhibiting. Which of the following gives the best explanation for why this is so? A) Acetylcholine has many different forms. B) Different postsynaptic cells will have different receptors. C) Postsynaptic cells have a dynamic and changing metabolism and respond differently at different times. D) Acetylcholine has a "dose effect." Larger doses are stimulating while small doses inhibit. Answer: B 18) Which of the following is NOT a function of dendrites? A) provide enormous surface area for receiving signals from other neurons B) generate nerve impulses and transmit them away from the cell body C) convey incoming messages toward the cell body D) produce short-distance signals called graded potentials Answer: B 19) Which of the choices below describes the ANS? A) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands B) motor fibers that conduct nerve impulses from the CNS to skeletal muscles C) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS D) sensory and motor neurons that supply the digestive tract Answer: A 20) These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid. A) ependymal cells B) Schwann cells C) oligodendrocytes D) astrocytes Answer: A 21) What does the central nervous system use to determine the strength of a stimulus? A) origin of the stimulus B) type of stimulus receptor C) frequency of action potentials D) size of action potentials Answer: C 22) Bipolar neurons are commonly ________. A) motor neurons B) called neuroglial cells C) found in ganglia D) found in the retina of the eye Answer: D 23) Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? A) cholinesterase B) norepinephrine C) acetylcholine D) gamma aminobutyric acid Answer: C 24) Which of the following describes the nervous system integrative function? A) senses changes in the environment B) analyzes sensory information, stores information, makes decisions C) responds to stimuli by gland secretion or muscle contraction Answer: B 25) The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. A) resting period B) repolarization C) depolarization D) absolute refractory period Answer: D 26) Which of the following is NOT a characteristic of neurons? A) They conduct impulses. B) They have extreme longevity. C) They are mitotic. D) They have an exceptionally high metabolic rate. Answer: C 27) Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? A) mechanically-gated channel B) voltage-gated channel C) leakage channel D) ligand-gated channel Answer: B 28) Loss of function in the enzyme acetylcholine esterase would result in which of the following? A) inability to release acetylcholine B) amplify or enhance the effect of ACh C) inability to destroy and remove acetylcholine from the synaptic cleft D) stimulation of the production of acetylcholine Answer: C 29) Which of the following is NOT a function of the autonomic nervous system? A) innervation of smooth muscle of the digestive tract B) innervation of cardiac muscle C) innervation of glands D) innervation of skeletal muscle Answer: D 30) Collections of nerve cell bodies outside the central nervous system are called ________. A) nuclei B) nerves C) ganglia D) tracts Answer: C 31) The term central nervous system refers to the ________. A) spinal nerves B) sensory (afferent) nerves C) brain and spinal cord D) somatic nerves Answer: C 32) A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. A) efferent neuron B) afferent neuron C) interneuron D) glial cell Answer: C 33) Saltatory conduction is made possible by ________. A) the myelin sheath B) large nerve fibers C) diphasic impulses D) erratic transmission of nerve impulses Answer: A 34) Which of the following is NOT a chemical class of neurotransmitters? A) amino acid B) biogenic amine C) ATP and other purines D) nucleic acid Answer: D 35) Which of the following is false or incorrect? A) An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold. B) A nerve impulse occurs if the excitatory and inhibitory effects are equal. C) An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane. Answer: B 36) Select the correct statement regarding chemical synapses. A) Cells with gap junctions use chemical synapses. B) The release of neurotransmitter molecules gives cells the property of being electrically coupled. C) Neurotransmitter receptors are located on the axons terminals of cells. D) The synaptic cleft uses the action potential to transmit a chemical signal to the postsynaptic cell. Answer: D 37) Which of the following correctly describes a graded potential? A) It travels long distances. B) It can have amplitudes of various sizes. C) It is initiated by voltage changes in the membrane. D) It has a depolarization, repolarization, and hyperpolarization phase. Answer: B 38) Schwann cells are functionally similar to ________. A) ependymal cells B) microglia C) oligodendrocytes D) astrocytes Answer: C 39) Immediately after an action potential has peaked, which of the following channels will open? A) voltage-gated sodium channels B) chemically-gated chloride channels C) voltage-gated calcium channels D) voltage-gated potassium channels Answer: D 40) An inhibitory postsynaptic potential (IPSP) is associated with ________. A) a change in sodium ion permeability B) hyperpolarization C) opening of voltage-regulated channels D) lowering the threshold for an action potential to occur Answer: B 41) Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? A) Specific sodium gates will open. B) Specific potassium gates will open. C) Sodium gates will open first, then close as potassium gates open. D) A single type of channel will open, permitting simultaneous flow of sodium and potassium. Answer: D 42) When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. A) postsynaptic potential B) excitatory potential C) action potential D) generator potential Answer: D 43) Which of the following is NOT true of graded potentials? A) They are short-lived. B) They can form on receptor endings. C) They increase amplitude as they move away from the stimulus point. D) They can be called postsynaptic potentials. Answer: C 44) Which of the following is true about the movement of ions across excitable living membranes? A) Ions always move actively across membranes through leakage channels. B) Ions always move passively across membranes. C) Sodium gates in the membrane can open in response to electrical potential changes. D) Ions always move from an area of higher concentration to an area of lower concentration. Answer: C 45) A second nerve impulse cannot be generated until ________. A) the membrane potential has been reestablished B) the Na ions have been pumped back into the cell C) proteins have been resynthesized D) all sodium gates are closed Answer: A 46) The interior surface of a neuron's plasma membrane at resting membrane potential will have a ________. A) positive charge and contains less sodium than outside of the cell B) negative charge and contains less sodium than outside of the cell C) negative charge and contains more sodium than outside of the cell D) positive charge and contains more sodium than outside of the cell Answer: B 47) If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon, ________. A) the impulse would move to the axon terminal only B) muscle contraction would occur C) the impulse would spread bidirectionally D) the impulse would move to the axon terminal only, and the muscle contraction would occur Answer: C 48) Which of the following neurotransmitters is the principal inhibitory neurotransmitter of the spinal cord? A) acetylcholine B) endorphin C) serotonin D) glycine Answer: D 49) Which of the following describes the excitatory postsynaptic potential? A) short distance hyperpolarization B) short distance depolarization C) opens K+ or Cl- channels D) moves membrane potential away from threshold Answer: B 11.4 Short Answer Questions 1) The part of the nervous system that conducts impulses from the CNS to the skeletal muscles is the ________ nervous system. Answer: somatic 2) Neuroglia found in the CNS that change the permeability of capillaries in the brain by binding to and surrounding these blood vessels are called ________. Answer: astrocytes 3) Which group of neurotransmitters play a role in emotional behavior and help regulate the biological clock? Answer: biogenic amine neurotransmitters 4) What mechanism is responsible for axonal transport? Answer: ATP-dependent "motor" proteins such as kinesin and dynein myosin are responsible. They propel cellular components along microtubules. 5) The synapse more common in embryonic nervous tissue than in adults is the ________. Answer: electrical synapse 6) When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing. Answer: parallel 7) When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane than would result from a single EPSP; this event is called ________ summation. Answer: temporal 8) What is the role of microglial cells and why are they so important in the CNS? Answer: In the presence of invading microbes, microglial cells become macrophages to phagocytize the microbes and neuronal debris. This protective role is important because cells of the immune system are denied access to the CNS. 9) Define synaptic delay. Answer: Synaptic delay reflects the time required for neurotransmitter release, diffusion across the synaptic cleft, and binding to receptors. 10) What is the difference between a direct acting neurotransmitter and an indirect acting neurotransmitter? Answer: Direct acting neurotransmitters bind to and open ion channels. Indirect acting neurotransmitters act through intracellular second-messenger molecules. 11) What function is served by the increased axon diameter at the nodes of Ranvier? Answer: Increased diameter results in less resistance to lengthwise intra-axonal flow. This results in increased speed of impulse propagation. 12) Imagine a neuron that has several hundred axonal knobs impinging on it. The majority of these axonal knobs are shown to be "firing." However, the neuron in question does not transmit an impulse. Give a valid explanation of why this could occur. Answer: Both excitatory and inhibitory potentials impinge on neurons. In this case, inhibitory postsynaptic potentials (IPSPs) outnumber EPSPs, and due to the IPSP neurotransmitter released and its action, the postsynaptic neuron is inhibited from "firing" (hyperpolarized). 13) At the biochemical level, what is the explanation of the hyperpolarization phase at the conclusion of the action potential? Answer: The voltage gated K+ channels are slow to open as well as to close. These channels will remain open long enough to hyperpolarize the cell. The K+ ions decrease the positive ion concentration momentarily below the normal -70mV and thus hyperpolarize the cell. This assists in preventing the AP from reversing direction. 14) What are the basic divisions of the peripheral nervous system? Answer: Sensory and motor divisions. Sensory has two divisions: the somatic and visceral. Motor has two divisions: the somatic and autonomic. The autonomic has two divisions: the sympathetic and parasympathetic. 15) Because all action potentials are alike, how does the brain separate situations that require immediate attention from ordinary "positional" reports? Answer: The importance of a stimulus is derived from the number of stimuli received from the same source. The frequency of impulse transmission indicates the stimulus intensity and the brain responds appropriately. 11.5 Clinical Questions 1) Multiple sclerosis (MS) is a disease in which the myelin sheaths are destroyed. What process does this interfere with and what would be the consequence? Answer: Demyelination interferes with saltatory conduction, which would result in a slowing down and even permanent cessation of nerve impulse propagation. S