Match each term to the correct statement. - A B C repolarization - A B C hyperpolarization - A B C depolarization A.

Match each term to the correct statement. A. The slow decline in potassium permeability is responsible for this. B. This phase is characterized by a rapid decrease in sodium permeability and a simultaneous increase in potassium permeability. C. The membrane is most permeable to sodium in this phase. All of the following statements about repolarization are correct EXCEPT: Membrane permeability to potassium is highest during repolarization. Repolarization is the declining phase of the action potential. During repolarization the membrane potential becomes more negative. Repolarization is due to less sodium leaving and more potassium entering the cell. An all-or-none event ____________________. always occurs when a depolarization reaches the trigger point known as threshold. frequently occurs if the depolarization membrane potential is -70 mV. seldom occurs at the axon hillock region. refers to the fact that weak stimuli, those that do not reach threshold, will not generate an action potential. During the relative refractory period a neuron will generate an action potential if it is depolarized to a value more positive threshold. True False During an action potential, voltage-gated sodium channels open rapidly, then inactivate, and finally reset to the closed state. True False During the absolute refractory period ____________________. All answers are correct. most potassium channels remain open. a neuron's voltage gated sodium and potassium channels are closed. a neuron cannot generate an action potential unless a very strong stimulus occurs. As the axon hillock depolarizes ____________________. voltage-gated sodium channels open slowly. sodium moves down its electrochemically gradient All answers are correct. the membrane becomes permeable to chloride. Which statement is CORRECT? Hyperpolarization results when sodium moves into the cell after the cell repolarizes. Hyperpolarization results in a membrane potential that is more negative than the resting membrane potential. All answers are correct. All voltage-gated potassium channels close after the cell repolarizes. Another term for a nerve impulse is action potential. True False Immediately after generating an action potential, a neuron can generate another one. True False When threshold is reached ____________________. the membrane potential becomes less negative. voltage-gated sodium channels open. All statements are correct. an action potential is generated. The rising phase of the action potential ends when the negative feedback loop is interrupted. True False Threshold refers to the voltage that opens the voltage-gated channels located in the axon hillock region of the neuron. True False The rising phase of an action potential ends when ____________________. voltage-gated potassium channels open. All answers are correct. time-sensitive sodium gates close. voltage-gated sodium channels inactivate. Voltage-gated potassium channels open when the action potential reaches its peak. True False Action potentials rarely have the same amplitude and duration. True False A myelinated axon will conduct an action potential faster than an unmyelinated axon. True False Open voltage-gated sodium channels result in ____________________. sodium moving out of the cell. sodium moving into the cell while chloride moves out. sodium moving into the cell. no net movement of sodium (equilibrium). Repolarization occurs when voltage-gated ____________________. sodium channels open allowing sodium to enter the cell. potassium channels open allowing potassium to leave the cell. potassium and sodium channels close. potassium and sodium channels open, allowing, sodium to enter the cell while potassium leaves the cell. The positive feedback loop is interrupted when voltage-gated sodium channels become inactive and voltage-gated potassium channels ____________________. close and then open. open. close. open and then close. An action potential ____________________. is also known as the resting membrane potential. occurs when sodium and potassium gates close. All answers are correct. refers to a large change in membrane potential from -70mV to +30mV and back to -70mV. When and only when a neuron reaches threshold, a positive feedback loop is established. True False