PhysioEx Exercise 3 Test Answers|100% CORRECT|VERY HELPFUL

PhysioEx Exercise 3 Test Answers When the stimulus intensity increases, _______. the number of action potentials increases In this activity, which of the following will increase the stimulus intensity? increasing the duration of the stimulus At threshold, axons will _______. Likely generate an action potential if refractory periods have elapsed. Longer stimuli will allow for _______. 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 _______. interspike interval Increase in stimulus intensity _______. increases the frequency of action potentials The frequency of action potentials is _______. the reciprocal of the interspike interval, and measured in hertz During the relative refractory period, _______. the stimulus must be above threshold to generate an action potential Which of the following occurs first in the generation of an action potential? The membrane depolarizes Which of the following occurs during depolarization? Sodium flows into the cell Which of the following occurs during repolarization? 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? leakage channels and voltage-gated potassium channels Why does the threshold increase when the interval between the stimuli decreases? Some sodium channels have been inactivated and cannot be reopened immediately During the relative refractory period, _______. 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 until the interval reaches the absolute refractory period When the stimulus voltage is increased, _______. a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting. 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 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 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 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 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 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 polariz