The properties shown in the figure can be measured in which of the following? C. revealed the quantitative movements of ions across the membrane that lead to an action potential. D. depolarization of the membrane. Decreases the conduction velocity of action potentials in that axon.
B. Oligodendrocites. The voltage-gated K+ channel has only one gate, which is sensitive to a membrane voltage of -50 mV. Which of the following is not a factor in the Nernst Equation? Theories Biological Psychology All-or-None Law for Nerves and Muscles By Kendra Cherry Kendra Cherry Facebook Twitter Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology. What is your feedback? Also, any stimulus that depolarizes the membrane to -55 mV or beyond will cause a large number of channels to open and an action potential will be initiated. A receptor potential, a synaptic potential or an action potential. These neurons are very short, so there is no major signal decrement.
Leakage channels and voltage-gated potassium channels. Sodium must be pumped out again later. Sodium leakage channels. Which of the following is used to block pain?
But it is vital to understanding what is happening. The voltage-gated Na+ channel actually has two gates. The minimum voltage that is required to generate an action potential is called the _______. Leakage channels contribute to the resting transmembrane voltage of the excitable membrane (Figure \(\PageIndex{5}\)). Oligodendrocytes provide the myelination in the peripheral nervous system. C. Membrane surface area to volume ratio. A voltage sensitive ion channel is a channel *a. whose conductance to an ion changes as the membrane potential changes. E. The motor neurons activate leg muscles. The central nervous system (CNS) includes the brain and spinal cord, while the peripheral nervous system (PNS) includes all the nerves that radiate from the CNS. The effects of lidocaine and tetrodotoxin were _______. Content is reviewed before publication and upon substantial updates.
Signal transmission rate is relatively fast. The voltage across the membrane due to ion concentration differences. These nonspecific channels allow cations—particularly Na+, K+, and Ca2+—to cross the membrane, but exclude anions. ISBN: 9781337520164. High concentration of voltage-gated Na+ channels at the axon hillock. The concentration of ions in extracellular and intracellular fluids is largely balanced, with a net neutral charge. C. increase in concentration of K+ ions. C. There is a greater capacitance in the lower panel at the point where voltage is measured. Why would this be the case based on propagation of the axon potential? Once that channel has returned to its resting state, a new action potential is possible, but it must be started by a relatively stronger stimulus to overcome the K+ leaving the cell. D. Electrogenic ion pumps. A. in the cell body. Sound waves or air currents vibrate the filiform hairs.
E. All of the above are true, none is false. The cell's ability to generate an action potential will not be affected in the first 10 minutes. Another term for nerve fiber. A cluster of cell bodies. There are a few different types of channels that allow Na+ to cross the membrane. Interactive Link Questions. D. The cell would no longer be in a steady state.
Action of the ATP-dependent Na-K pump, which recreates the ion gradients. Pre-synaptic inhibition prevents over-firing and cellular exhaustion. B. its membrane permeability. Suprathreshold for all of the axons. C. Cl– may be at passive equilibrium in some cells. The reciprocal of the interspike interval. K+ or Cl- channels alone. It is the movement of ions that activates the nerve impulse or action potential, which then is conveyed from nerve cell to nerve cell until reaching the CNS. C. The concentration of K+ would be equal on both sides of the membrane. However, it does not open as quickly as the voltage-gated Na+ channel does. B. proportional relationship to the square root of.
B) Only a small change occurred, because the sodium channels were mostly open. Learning Objectives. Sodium conductance changes more slowly than does potassium conductance as membrane potential changes. D. Na+ reaches equilibrium across the neural membrane and stops leaking in. What does a mechanically gated channel respond to? The conductance of an ion depends on *a. the density of open channels for that ion in the membrane. The ion's concentration gradient, the membrane potential and the action of an ion exchange pump, only.
Threshold frequency. Requires the appropriate stimulus. There are two phases of the refractory period: the absolute refractory period and the relative refractory period. The receptor potential is the change that occurs in a sensory neuron in response to an action potential. C) What ratio of conjugate base to acid is required in the buffer? C. Neurons form highly discrete lines of communication. Some sodium channels have been inactivated and cannot be reopened immediately. Change in a cell membrane potential from rest toward zero. Answer: The properties of electrophysiology are common to all animals, so using the leech is an easier, more humane approach to studying the properties of these cells. E. The passive properties of the axon membrane. During the "falling" phase, K+ permeability increases.
E. The number of voltage-gated Na+ channel per unit surface area. The ionic basis for an action potential is usually the opening of a. Na+ channels alone. An action potential from node to node of a myelinated nerve.