At a Chemical Synapse, the Intensity of the Stimulus is Coded by

Which of the following statements about receptor potentials is FALSE? 1) A) The receptor proteins respond to stimuli. B) The receptor potential is carried by neuroglia. C) Odor molecules can act as stimuli. D) They can trigger an action potential. The receptor potential is carried by neuroglia. Which of the following is NOT a functional region of a neuron? 2) A) input region B) secretory region C) receiving region D) conducting region input region The conducting region of the neuron is the _______. 3) A) cell body B) axon C) axon terminal D) dendrite axon The typical concentration of sodium is _______. 4) A) lower than potassium intracellularly B) higher than potassium intracellularly C) lower than potassium extracellularly D) the same as potassium intracellularly lower than potassium intracellularly Which of the following describes a change from the resting membrane potential? 5) A) a receptor potential B) an action potential C) a synaptic potential D) a receptor potential, a synaptic potential or an action potential a receptor potential, a synaptic potential or an action potential What effect did increasing the extracellular potassium have on the resting membrane potential? 6) A) The resting membrane potential disappeared. B) The resting membrane potential became more negative. C) The resting membrane potential did not change. D) The resting membrane potential became less negative. The resting membrane potential became less negative. What effect did decreasing the extracellular sodium have on the resting membrane potential? 7) A) Only a small change occurred, because the resting neuron is not very permeable to sodium. B) Only a small change occurred, because the sodium channels were mostly open. C) The resting membrane potential disappeared. D) The resting membrane potential became less negative. Only a small change occurred, because the resting neuron is not very permeable to sodium. The channels that provide for the movement of potassium in the resting neuron are _______. 8) A) chemically gated B) leakage and chemically gated C) leakage D) voltage gated leakage Establishing the resting membrane potential requires energy through the use of the _______. 9) A) potassium-glucose pump B) sodium leakage channels C) sodium-glucose pump D) sodium potassum pump sodium potassum pump The receptor potential is generated at the _______. 10) A) conducting region B) receiving region C) secretory region D) output region receiving region Sensory transduction is defined as _______. 11) A) a change in the amplitude of a receptor potential B) the conversion of a light stimulus into pain C) the disappearance of the perception of a stimulus D) the conversion of a stimulus to a change in membrane potential the conversion of a stimulus to a change in membrane potential The receptor potential _______. 12) A) can be graded with stimulus intensity B) amplitude can vary with the stimulus intensity C) amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity D) requires the appropriate stimulus amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity Which of the following describes a depolarization? 13) A) The membrane becomes less polarized. B) The membrane potential becomes more polarized. C) The membrane, which was formerly not polarized, now is polarized. D) The membrane potential becomes more negative. The membrane becomes less polarized. Which of the following was able to detect pressure? 14) A) olfactory receptor B) Pacinian corpuscle C) free nerve ending D) the Pacinian corpuscle and the free nerve ending the Pacinian corpuscle and the free nerve ending Which of the following does NOT describe graded potentials? 15) A) They are always depolarizing. B) They vary with the intensity of the stimulus. C) They are local changes. D) They are changes to the membrane potential. They are always depolarizing Which of the following responded to a chemical stimulus? 16) A) Pacinian corpuscle B) free nerve ending C) olfactory receptor D) both the Pacinian corpuscle and the olfactory receptor olfactory receptor When the intensity of the appropriate stimulus was increased, the amplitude of the response _______. 17) A) did not change B) increased C) decreased D) was zero increased A nerve is _______. 18) A) a cluster of cell bodies B) another term for a neuron C) a bundle of axons D) another term for nerve fiber a bundle of axons The region on the neuron where action potentials are generated is called the ______. 19) A) dendrite B) depolarization zone C) trigger zone D) stimulator zone trigger zone 20) In this simulation, ___________________ will be used to stimulate the axon. 20) A) voltage B) light C) heat D) chemicals voltage We describe the regeneration of the action potential down the membrane of the axon of the neuron as _______. 21) A) hyperpolarization B) propagation C) conduction D) conduction and propagation conduction and propagation The minimum voltage that is required to generate an action potential is called the _______. 22) A) depolarization voltage B) trigger voltage C) threshold voltage D) propagation voltage threshold voltag Increasing the voltage resulted in which of the following? 23) A) a decrease in the rate of propagation of the action potential B) an increase in the size of the action potential C) no change to the action potential D) an increase in the rate of propagation of the action potential no change to the action potential An axon that is more negative than the resting membrane potential is said to be _______. 24) A) depolarized B) graded C) hyperpolarized D) at threshold hyperpolarized If an increase in extracellular potassium would depolarize a neuron, what would be the effect of the increased potassium? 25) A) It would decrease the flow of sodium out of the cell. B) It would increase the flow of sodium out of the cell. C) It would change the membrane potential to a more negative value. D) It would change the membrane potential to a less negative value. It would change the membrane potential to a less negative value. An action potential requires _______. 26) A) voltage-gated sodium channels to open B) sodium to flow with its electrochemical gradient C) chemically gated sodium channels to open D) voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient To reach threshold, the amount of sodium _______. 27) A) exiting the cell must overcome the potassium entering B) exiting the cell must overcome the potassium exiting C) entering the cell must overcome the potassium exiting D) entering the cell must overcome the potassium entering entering the cell must overcome the potassium exiting Which of the following blocks voltage-gated sodium channels? 28) A) lidocaine B) tetrodotoxin C) pufferfish toxin D) tetrodotoxin, pufferfish toxin and lidocaine tetrodotoxin, pufferfish toxin and lidocaine Which of the following is used to block pain? 29) A) tetrodotoxin B) lidocaine C) pufferfish toxin D) tetrodotoxin, pufferfish toxin and lidocaine lidocaine Which of the following occurred in the presence of tetrodotoxin? 30) A) The number of action potentials increased. B) The number of action potentials decreased. C) The size of the action potential decreased. D) The size of the action potential increased. The number of action potentials decreased. Which of the following occurred in the presence of tetrodotoxin? 31) A) An action potential was always seen at R2. B) An action potential was always seen at R1 and R2. C) An action potential was always seen at R1. D) All action potentials were missing. An action potential was always seen at R1. In the presence of lidocaine, the action potential was NOT affected at R1 because _______. 32) A) action potential propagation is in one direction B) lidocaine was applied upstream of R1 C) lidocaine doesn't have an effect on the generation of action potentials D) there are no voltage-gated sodium channels to be affected action potential propagation is in one direction The effects of lidocaine and tetrodotoxin were _______. 33) A) identical B) similar, but tetrodotoxin had a greater effect C) very different, because lidocaine had no effect D) similar, but lidocaine had a greater effect similar, but tetrodotoxin had a greater effect Which of the following occurs first in the generation of an action potential? 34) A) Voltage-gated potassium channels open. B) The membrane repolarizes. C) The membrane depolarizes. D) Voltage-gated sodium channels open The membrane depolarizes. Which of the following occurs during depolarization? 35) A) Voltage-gated potassium channels open. B) Some voltage-gated sodium channels inactivate. C) Sodium flows into the cell. D) Both A and C occur. E) All of the above occur. Sodium flows into the cell Which of the following occurs during repolarization? 36) A) Voltage-gated potassium channels open, potassium flows into the cell and some voltage-gated sodium channels inactivate. B) Voltage-gated potassium channels open. C) Potassium flows into the cell. D) Some voltage-gated sodium channels inactivate. E) Voltage-gated potassium channels open and potassium flows into the cell. Voltage-gated potassium channels open, potassium flows into the cell and some voltage-gated sodium channels inactivate. Which of the following allow the movement of potassium through the neuronal membrane? 37) A) voltage-gated potassium channels B) leakage channels C) chemically gated potassium channels D) voltage-gated potassium channels and chemically gated potassium channels E) leakage channels and voltage-gated potassium channels leakage channels and voltage-gated potassium channels Why does the threshold increase when the interval between the stimuli decreases? 38) A) Potassium is flowing into the cell. B) Some sodium channels have been inactivated and cannot be reopened immediately. C) Calcium is flowing out the cell. D) Sodium is flowing out of the cell. Some sodium channels have been inactivated and cannot be reopened immediately. 39) During the relative refractory period, _______. 39) A) a second action potential cannot be generated, no matter how strong the stimulus B) an action potential can be generated if the stimulus is above threshold C) an action potential can be generated if the stimulus is above threshold; also the flow of potassium is opposing depolarization D) the flow of potassium is opposing depolarization an action potential can be generated if the stimulus is above threshold; also the flow of potassium is opposing depolarization When the interval between the stimuli decreases, _______. 40) A) a second action potential is generated until the interval reaches the absolute refractory period B) a second action potential is generated as long as the stimulus is above threshold C) a second action potential is generated until the interval reaches the relative refractory period D) a second action potential is generated regardless of the stimulus and the interval a second action potential is generated until the interval reaches the absolute refractory period When the stimulus voltage is increased, _______. 41) A) a greater-than-threshold depolarization results B) a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting C) sodium permeability into the cell decreases D) sodium permeability into the cell increases to overcome the potassium exiting a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting When the stimulus intensity increases, _______. 42) A) the number of action potentials increases B) the size of the action potential increases C) the size of the action potential decreases D) the number of action potentials decreases the number of action potentials increase In this activity, which of the following will increase the stimulus intensity? 43) A) decreasing the absolute refractory period B) increasing the relative refractory period C) increasing the absolute refractory period D) increasing the duration of the stimulus increasing the duration of the stimulus At threshold, an axon will _______. 44) A) generate an action potential during the relative refractory period B) always generate an action potential C) generate an action potential after the absolute and relative refractory periods have elapsed D) generate an action potential during the absolute refractory period generate an action potential after the absolute and relative refractory periods have elapsed Longer stimuli will allow for _______. 45) A) the absolute refractory period to finish B) more action potentials to occur C) the relative refractory period to finish D) more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish The time interval between action potentials is called the _______. 46) A) potential frequency B) interspike interval C) threshold frequency D) threshold interval interspike interval Increase in stimulus intensity _______. 47) A) increases the size of the action potential B) has no effect on action potentials C) increases the frequency of action potentials D) increases the duration of the action potential increases the frequency of action potentials The frequency of action potentials is _______. 48) A) the reciprocal of the interspike interval B) measured in hertz C) measured in hertz and the same as the relative refractory period D) the reciprocal of the interspike interval and measured in hertz E) the same as the relative refractory period the reciprocal of the interspike interval and measured in hertz During the relative refractory period, _______. 49) A) adaptation occurs B) no action potentials are generated C) the stimulus must be above threshold to generate an action potential D) the stimulus must be below threshold to generate an action potential the stimulus must be above threshold to generate an action potential Which of the following is described correctly? 50) A) Oligodendrocytes provide the myelination in the peripheral nervous system. B) Schwann cells provide the myelination in the central nervous system. C) Schwann cells provide the myelination in the peripheral nervous system. D) Astrocytes provide the myelination in the central nervous system. schwann cells provide the myelination in the peripheral nervous system. The rate with which an action potential travels along an axon _______. 51) A) is called the conduction velocity B) is measured in volts/sec C) is measured in meters/sec D) is called the conduction velocity and is measured in volts/sec E) is called the conduction velocity and is measured in meters/sec is called the conduction velocity and is measured in meters/sec Which of the following describes a B fiber? 52) A) large diameter, lightly myelinated B) small diameter, unmyelinated C) medium diameter, lightly myelinated D) small diameter, lightly myelinated medium diameter, lightly myelinated The nodes of Ranvier are _______. 53) A) locations on the axon where the myelin sheath is very heavy B) locations on the axon where the myelin sheath is absent C) a type of glial cell D) trigger zones of an axon locations on the axon where the myelin sheath is absen Which fibers generate the smallest value for conduction velocity? 54) A) B fibers B) D fibers C) C fibers D) A fibers C fiber The time interval for conduction would be shortest with 55) A) the smallest unmyelinated axons B) the smallest and most heavily myelinated axons C) the largest unmyelinated axons D) the largest and most heavily myelinated axons the largest and most heavily myelinated axons Increasing the amount of myelination _______. 56) A) has no effect on the time between action potentials B) increases the time between action potentials C) increases the time between action potentials only for small-diameter axons D) decreases the time between action potentials decreases the time between action potentials In this activity, the stimulus voltage used was _______. 57) A) suprathreshold for all of the axons B) altered to accommodate the structural differences C) the same for all of the axons D) the same for all of the axons and suprathreshold for all of the axons the same for all of the axons and suprathreshold for all of the axons A synaptic cleft can be found between _______. 58) A) a neuron and a muscle B) a neuron and a gland C) a neuron and another neuron D) a neuron and another neuron, a neuron and a muscle, as well as a neuron and a gland a neuron and another neuron, a neuron and a muscle, as well as a neuron and a gland The membrane potential that occurs when neurotransmitters bind to their receptors is called _______. 59) A) a postsynaptic potential B) an action potential C) an action potential and a receptor potential D) a receptor potential a postsynaptic potential The release of neurotransmitter occurs _______. 60) A) at the motor end plate B) all along the axon C) at the axon terminal D) from the dendrites at the axon terminal Which of the following occurs first? 61) A) An action potential arrives at the axon terminal. B) Extracellular calcium enters the axon terminal. C) Synaptic vesicles exit by exocytosis. D) Voltage-gated calcium channels are opened An action potential arrives at the axon terminal. At a chemical synapse, the intensity of the stimulus is coded for by _______. 62) A) the size of the action potential and the amount of neurotransmitter released B) the amount of neurotransmitter released and the amount of calcium that enters the axon terminal C) the amount of calcium that enters the axon terminal D) the size of the action potential E) the amount of neurotransmitter released the amount of neurotransmitter released and the amount of calcium that enters the axon terminal When the calcium was removed from the extracellular solution, _______. 63) A) no neurotransmitter was released B) the amount of neurotransmitter released decreased C) the amount of neurotransmitter released increased D) the amount of neurotransmitter released did not change no neurotransmitter was released When magnesium was added to the extracellular solution, _______. 64) A) no neurotransmitter was released B) the amount of neurotransmitter released increased C) the amount of neurotransmitter released decreased D) the amount of neurotransmitter released did not change the amount of neurotransmitter released decreased Calcium and magnesium are both _______. 65) A) monovalent cations B) divalent anions C) divalent cations D) monovalent anions divalent cations A single action potential is described as _______. 66) A) graded by the functional area involved B) not graded C) graded by the frequency of the stimulus D) graded by the intensity of the stimulus not graded A suprathreshold stimulus results in _______. 67) A) more action potentials B) fewer action potentials C) the disappearance of action potentials D) larger action potentials more action potentials A depolarizing synaptic potential is also known as _______. 68) A) a hyperpolarizing postsynaptic potential B) an inhibitory postsynaptic potential C) an excitatory presynaptic potential D) an excitatory postsynaptic potential an excitatory postsynaptic potential The stimulus for graded potentials includes _______. 69) A) sensory stimuli and neurotransmitter B) sensory stimuli C) neurotransmitter D) voltage sensory stimuli and neurotransmitter A weak, subthreshold stimulus will result in _______. 70) A) a small depolarization at the receiving end of the interneuron B) an action potential at the receiving end of the neuron C) release of neurotransmitter at the axon terminal of the sensory neuron D) a small depolarization at the receiving end of the neuron a small depolarization at the receiving end of the neuron Which stimulus was at or above threshold? 71) A) strong B) weak C) moderate D) the moderate and strong stimuli the moderate and strong stimuli Increasing the strength of the stimulus applied to the sensory receptor increased _______. 72) A) the amount of neurotransmitter released at the axon terminal of the sensory neuron B) the frequency of action potentials in the sensory neuron C) the frequency of action potentials in the interneuron D) the frequency of action potentials in the sensory neuron and the amount of neurotransmitter released at the axon terminal of the sensory neuron E) the frequency of action potentials in the sensory neuron, the amount of neurotransmitter released at the axon terminal of the sensory neuron and the frequency of action potentials in the interneuron the frequency of action potentials in the sensory neuron, the amount of neurotransmitter released at the axon terminal of the sensory neuron and the frequency of action potentials in the interneuron An excitatory postsynaptic potential occurs _______. 73) A) at the axon terminal of the interneuron B) at the receiving end of the sensory neuron C) at the receiving end of the interneuron D) at the axon terminal of the sensory neuron at the receiving end of the interneuron Which of the following statements about receptor potentials is FALSE? -Odor molecules can act as stimuli. -The receptor potential is carried by neuroglia. -The receptor proteins respond to stimuli. -They can trigger an action potential. The receptor potential is carried by neuroglia. Which of the following is NOT a functional region of a neuron? secretory region conducting region receiving region medullary region medullary region The conducting region of the neuron is the _______. cell body axon axon terminal dendrite axon The typical concentration of sodium is _______. - the same as potassium intracellularly. - lower than potassium extracellularly. - lower than potassium intracellularly. - higher than potassium intracellularly. - lower than potassium intracellularly. Which of the following describes a change from the resting membrane potential? - an action potential - a synaptic potential - a receptor potential - a receptor potential, a synaptic potential or an action potential a receptor potential, a synaptic potential or an action potential What effect did increasing the extracellular potassium have on the resting membrane potential? - The resting membrane potential became less negative. - The resting membrane potential became more negative. - The resting membrane potential did not change. - The resting membrane potential disappeared. The resting membrane potential became less negative. What effect did decreasing the extracellular sodium have on the resting membrane potential? - Only a small change occurred, because the sodium channels were mostly open. - The resting membrane potential disappeared. - Only a small change occurred, because the resting neuron is not very permeable to sodium. - The resting membrane potential became less negative. Only a small change occurred, because the resting neuron is not very permeable to sodium. The channels that provide for the movement of potassium in the resting neuron are _______. - leakage and chemically gated. - chemically gated - voltage gated - leakage leakage Establishing the resting membrane potential requires energy through the use of the _______. - sodium-glucose pump - potassium-glucose pump - sodium-potassium pump - sodium leakage channels sodium-potassium pump The receptor potential is generated at the _______. receiving region conducting region output region secretory region receiving region Sensory transduction is defined as _______. - the conversion of a stimulus to a change in membrane potential - the disappearance of the perception of a stimulus - the conversion of a light stimulus into pain - a change in the amplitude of a receptor potential - the conversion of a stimulus to a change in membrane potential The receptor potential _______. - can be graded with stimulus intensity - amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity - amplitude can vary with the stimulus intensity - requires the appropriate stimulus amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity Which of the following describes a depolarization? - The membrane potential becomes more polarized. - The membrane potential becomes more negative. - The membrane becomes less polarized. - The membrane, which was formerly not polarized, now is polarized. The membrane becomes less polarized. Which of the following was able to detect pressure? - the Pacinian corpuscle and the free nerve ending - free nerve ending - olfactory receptor - Pacinian corpuscle the Pacinian corpuscle and the free nerve ending Which of the following does NOT describe graded potentials? - They vary with the intensity of the stimulus. - They are changes to the membrane potential. - They are always depolarizing. - They are local changes. They are always depolarizing. Which of the following responded to a chemical stimulus? - Pacinian corpuscle - free nerve ending - olfactory receptor - both the Pacinian corpuscle and the olfactory receptor olfactory receptor When the intensity of the appropriate stimulus was increased, the amplitude of the response _______. was zero did not change decreased increased increased A nerve is _______. another term for a neuron a cluster of cell bodies a bundle of axons another term for nerve fiber a bundle of axons The region on the neuron where action potentials are generated is called the ______. trigger zone depolarization zone stimulator zone dendrite trigger zone In this simulation, ___________________ will be used to stimulate the axon. light heat voltage chemicals voltage We describe the regeneration of the action potential down the membrane of the axon of the neuron as _______. hyperpolarization conduction or propagation conduction propagation conduction or propagation The minimum voltage that is required to generate an action potential is called the _______. depolarization voltage propagation voltage threshold voltage trigger voltage threshold voltage Increasing the voltage resulted in which of the following? - an increase in the rate of propagation of the action potential - an increase in the size of the action potential - a decrease in the rate of propagation of the action potential - no change to the action potential no change to the action potential An axon that is more negative than the resting membrane potential is said to be _______. depolarized hyperpolarized at threshold graded hyperpolarized If an increase in extracellular potassium hyperpolarizes a neuron, which of the following would be correct? -It would change the membrane potential to a more negative value. -It would decrease the flow of sodium out of the cell. -It would change the membrane potential to a less negative value. -It would increase the flow of sodium out of the cell. -It would change the membrane potential to a more negative value. An action potential requires _______. - voltage-gated sodium channels to open - sodium to flow with its electrochemical gradient - chemically gated sodium channels to open - voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient To reach threshold, the amount of sodium _______. - entering the cell must overcome the potassium exiting - exiting the cell must overcome the potassium exiting - entering the cell must overcome the potassium entering - exiting the cell must overcome the potassium entering entering the cell must overcome the potassium exiting Which of the following blocks voltage-gated sodium channels? lidocaine tetrodotoxin tetrodotoxin and lidocaine potassium tetrodotoxin and lidocaine Which of the following is used to block pain? tetrodotoxin tetrodotoxin and lidocaine lidocaine potassium lidocaine Which of the following occurred in the presence of tetrodotoxin? The size of the action potential decreased. The number of action potentials increased. The number of action potentials decreased. The size of the action potential increased. The number of action potentials decreased. Which of the following occurred in the presence of tetrodotoxin? An action potential was always seen at R1. All action potentials were missing. An action potential was always seen at R1 and R2. An action potential was always seen at R2. An action potential was always seen at R1. In the presence of lidocaine, the action potential was NOT affected at R1 because _______. - lidocaine was applied downstream of R1 - there are no voltage-gated sodium channels to be affected - lidocaine doesn't have an effect on the generation of action potentials - lidocaine was applied upstream of R1 lidocaine was applied downstream of R1 The effects of lidocaine and tetrodotoxin were _______. - identical - similar, but lidocaine had a greater effect - similar, but tetrodotoxin had a greater effect - very different, because lidocaine had no effect similar, but tetrodotoxin had a greater effect Which of the following occurs first in the generation of an action potential? Voltage-gated sodium channels open. Voltage-gated potassium channels open. The membrane depolarizes. The membrane repolarizes. The membrane depolarizes. Which of the following occurs during depolarization? Both A and C occur. Voltage-gated sodium channels close. Voltage-gated potassium channels close. Sodium flows into the cell. All of the above occur. Sodium flows into the cell. Which of the following occurs during repolarization? - Voltage-gated sodium channels open. Sodium flows into the cell. - Voltage-gated potassium channels remain open and some voltage-gated sodium channels inactivate. Potassium flows into the cell. - Voltage-gated sodium channels open and some voltage-gated potassium channels inactivate. Sodium flows out of the cell. - Voltage-gated potassium channels open and some voltage-gated sodium channels inactivate. Potassium flows out of the cell. - Voltage-gated potassium channels open and potassium flows into the cell. Voltage-gated potassium channels open and some voltage-gated sodium channels inactivate. Potassium flows out of the cell. Which of the following allow the movement of potassium through the neuronal membrane? simple diffusion leakage channels leakage channels and voltage-gated potassium channels voltage-gated potassium channels leakage channels and voltage-gated potassium channels Why does the threshold increase when the interval between the stimuli decreases? - Potassium is flowing into the cell. - Calcium is flowing out the cell. - Sodium is flowing out of the cell. - Some sodium channels have been inactivated and cannot be reopened immediately. Some sodium channels have been inactivated and cannot be reopened immediately During the relative refractory period, _______. - a second action potential cannot be generated, no matter how strong the stimulus. - the flow of potassium is also depolarizing the neuron. - another action potential can be generated provided the stimulus is large enough. - another action potential can be generated provided the stimulus is relatively smaller than the original stimulus. another action potential can be generated provided the stimulus is large enough When the interval between the stimuli decreases, _______. - a second action potential is generated as long as the stimulus is above threshold - a second action potential is generated until the interval reaches the relative refractory period - a second action potential is generated until the interval reaches the absolute refractory period - a second action potential is generated regardless of the stimulus and the interval a second action potential is generated until the interval reaches the absolute refractory period When the stimulus voltage is increased, _______. - sodium permeability into the cell increases to overcome the potassium exiting - a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting. - a greater-than-threshold depolarization results - sodium permeability into the cell decreases a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting When the stimulus intensity increases, _______. - the number of action potentials decreases - the size of the action potential decreases - the size of the action potential increases - the number of action potentials increases the number of action potentials increases In this activity, which of the following will increase the stimulus intensity? - increasing the absolute refractory period - decreasing the absolute refractory period - increasing the duration of the stimulus - increasing the relative refractory period increasing the duration of the stimulus At threshold, axons will _______. - Usually be at the end of their absolute refractory period. - Begin to hyperpolarize the membrane potential. - Likely generate an action potential if refractory periods have elapsed. - Always generate an action potential. Likely generate an action potential if refractory periods have elapsed. Longer stimuli will allow for _______. -the absolute refractory period to finish - more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish - the relative refractory period to finish - more action potentials to occur more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish The time interval between action potentials is called the _______. potential frequency threshold interval interspike interval threshold frequency interspike interval Increase in stimulus intensity _______. - increases the duration of the action potential - increases the frequency of action potentials - has no effect on action potentials - increases the size of the action potential increases the frequency of action potentials The frequency of action potentials is _______. - measured in hertz, and the same as the relative refractory period - the reciprocal of the interspike interval, and measured in hertz - the same as the relative refractory period - the reciprocal of the interspike interval - measured in hertz - the reciprocal of the interspike interval, and measured in hertz During the relative refractory period, _______. - adaptation occurs - the stimulus must be above threshold to generate an action potential - the stimulus must be below threshold to generate an action potential - no action potentials are generated the stimulus must be above threshold to generate an action potential Which of the following is described correctly? - Schwann cells provide the myelination in the peripheral nervous system. - Astrocytes provide the myelination in the central nervous system. - Oligodendrocytes provide the myelination in the peripheral nervous system. - Schwann cells provide the myelination in the central nervous system. Schwann cells provide the myelination in the peripheral nervous system. The rate with which an action potential travels along an axon _______. - is measured in meters/sec - is called the conduction velocity - is called the conduction velocity and is measured in volts/sec - is measured in volts/sec - is called the conduction velocity and is measured in meters/sec is called the conduction velocity and is measured in meters/sec Which of the following describes a B fiber? - small diameter, unmyelinated - large diameter, lightly myelinated - medium diameter, lightly myelinated - small diameter, lightly myelinated medium diameter, lightly myelinated The nodes of Ranvier are _______. - locations on the axon where the myelin sheath is very heavy - trigger zones of an axon - a type of glial cell - locations on the axon where the myelin sheath is absent locations on the axon where the myelin sheath is absent Which fibers generate the smallest value for conduction velocity? A fibers B fibers D fibers C fibers C fibers The time interval for conduction would be shortest with - the largest unmyelinated axons - the smallest and most heavily myelinated axons - the largest and most heavily myelinated axons - the smallest unmyelinated axons the largest and most heavily myelinated axons Increasing the amount of myelination _______. - increases the time between action potentials - increases the time between action potentials only for small-diameter axons - decreases the time between action potentials - has no effect on the time between action potentials decreases the time between action potentials In this activity, the stimulus voltage used was _______. - altered to accommodate the structural differences - the same for all of the axons - suprathreshold for all of the axons - the same for all of the axons and suprathreshold for all of the axons the same for all of the axons and suprathreshold for all of Which neuroglial cell type surrounds the cell bodies of neurons in the peripheral nervous system satellite cell Which cell type is highlighted? neuroglial cell Which structures are highlighted? nodes of Ranvier Which of the following is synthesized in the highlighted structure? ribosomal RNA Which structures are highlighted? Schwann cell nuclei Which tissue is highlighted? white matter Which structure is highlighted? axon hillock Which structures are highlighted? axons Which structure is highlighted? cell body Which tissue is highlighted? endoneurium The highlighted structure consists of a bundle of ________. axons Which structure is highlighted? ventral funiculus Which structure is highlighted? gray commissure Which tissue is highlighted? gray matter Which neuroglial cell type forms the myelin sheath in the peripheral nervous system? Schwann cell Which structures are highlighted? myelinated nerve fiber Which of the following statements about receptor potentials is FALSE? The receptor potential is carried by neuroglia. Which of the following is NOT a functional region of a neuron? medullary region The conducting region of the neuron is the _______. axon The typical concentration of sodium is _______. lower than potassium intracellularly. Which of the following describes a change from the resting membrane potential? a receptor potential, a synaptic potential or an action potential What effect did increasing the extracellular potassium have on the resting membrane potential? The resting membrane potential became less negative. What effect did decreasing the extracellular sodium have on the resting membrane potential? Only a small change occurred, because the resting neuron is not very permeable to sodium. The channels that provide for the movement of potassium in the resting neuron are _______. leakage Establishing the resting membrane potential requires energy through the use of the _______. sodium-potassium pump The receptor potential is generated at the _______. receiving region Sensory transduction is defined as _______. the conversion of a stimulus to a change in membrane potential The receptor potential _______. amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity Which of the following describes a depolarization? The membrane becomes less polarized. Which of the following was able to detect pressure? the Pacinian corpuscle and the free nerve ending Which of the following does NOT describe graded potentials? They are always depolarizing. Which of the following responded to a chemical stimulus? olfactory receptor When the intensity of the appropriate stimulus was increased, the amplitude of the response _______. increased A nerve is _______. a bundle of axons The region on the neuron where action potentials are generated is called the ______. trigger zone In this simulation, ___________________ will be used to stimulate the axon. voltage We describe the regeneration of the action potential down the membrane of the axon of the neuron as _______. conduction or propagation The minimum voltage that is required to generate an action potential is called the _______. threshold voltage Increasing the voltage resulted in which of the following? no change to the action potential An axon that is more negative than the resting membrane potential is said to be _______. hyperpolarized If an increase in extracellular potassium hyperpolarizes a neuron, which of the following would be correct? It would change the membrane potential to a more negative value. An action potential requires _______. voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient To reach threshold, the amount of sodium _______. entering the cell must overcome the potassium exiting Which of the following blocks voltage-gated sodium channels? tetrodotoxin and lidocaine Which of the following is used to block pain? lidocaine Which of the following occurred in the presence of tetrodotoxin? The number of action potentials decreased. Which of the following occurred in the presence of tetrodotoxin? An action potential was always seen at R1. In the presence of lidocaine, the action potential was NOT affected at R1 because _______. lidocaine was applied downstream of R1 The effects of lidocaine and tetrodotoxin were _______. similar, but tetrodotoxin had a greater effect A synaptic cleft, or synaptic gap, can be found between a neuron and ______. All of these. The membrane potential that occurs when neurotransmitters bind to their receptors is called _______. a postsynaptic potential The release of neurotransmitter occurs _______. at the axon terminal Which of the following occurs first? An action potential arrives at the axon terminal. At a chemical synapse, the intensity of the stimulus is coded by _______. the amount of neurotransmitter released and the amount of calcium that enters the axon terminal When the calcium was removed from the extracellular solution, _______. no neurotransmitter was released When magnesium was added to the extracellular solution, _______. the amount of neurotransmitter released decreased Calcium and magnesium are both _______. divalent cations A weak, subthreshold stimulus will result in _______. a small depolarization at the receiving end of the neuron Which stimulus was at or above threshold? the moderate and strong stimuli Increasing the strength of the stimulus applied to the sensory receptor increased _______. the frequency of action potentials in the sensory neuron, the amount of neurotransmitter released at the axon terminal of the sensory neuron and the frequency of action potentials in the interneuron An excitatory postsynaptic potential occurs _______. at the receiving end of the interneuron What are the four nitrogenous bases? Adenine, Guanine, Cytosine, and Thymine How do these bases pair with each other? A pairs with T, C pairs with G True or False? DNA has equal amounts of Adenine and Thymine, and equal amounts of Cytosine and Guanine. True What does DNA stand for? DNA is short for Deoxyribonucleicacid. What is replication? Replication is the act of making an exact copy of DNA. What is semi-conservative replication? In semi-conservative replication, each strand of the original molecule acts as a template for the synthesis of a new complementary DNA molecule What is RNA? RNA is a nucleic acid that is a messenger between DNA and the ribosomes. What does RNA stand for? RNA is short for Ribonucleicacid. What are the differences between DNA and RNA? While the sugar for DNA is deoxyribose, the sugar for RNA is simply ribose. DNA is double stranded, while RNA has a single strand. Finally, RNA has a base called uracil to replace thymine in DNA. What is transcription? Transcription is the process by which DNA is copied into mRNA. Where does the transcription process occur? Transcription occurs in the nucleus. What is mRNA? mRNA, or Messenger RNA, is the copy of the DNA that transfers the information from the nucleus to the ribosomes. What are proteins made of? Proteins are made up of amino acids. What is tRNA? Transfer RNA is what matches up with the messenger RNA and has amino acids on top. What is a codon? A codon is a combination of 3 nucleotides on a strand of mRNA What is an anticodon? An anticodon is a combination of 3 nucleotides on a strand of tRNA What is translation? Translation is the decoding of an mRNA message into proteins. Where does translation occur? Translation occurs in the cytoplasm. What shape is DNA? DNA is in the shape of a double helix. What is the relation between genetic information and DNA? DNA is found within chromosomes, and is composed of genes and genetic information. How many chromosomes are found in body cells of humans? 46 How many chromosomes are found in gametes? Half, 23 What happens in DNA replication? In DNA replication, the DNA molecule untwists, and enzymes, called DNA polymerase, match up freefloating nucleotides to one of the original DNA strands. One DNA strand acts as a template for a new strand- two identical DNA molecules are made. What is the purpose of RNA? RNA carries information made by DNA, and aids in the synthesis of proteins. What is protein synthesis? Protein synthesis is the process by which RNA directs cell organelles, such as ribosomes, to make proteins and amino acids. What is a polypeptide? A polypeptide is a protein molecule.