Action potential or impulses
Neurotransmitters that bind to the postsynaptic membrane generally generate a postsynaptic potential, which can be either excitatory (EPSP) or inhibitory (IPSP). EPSPs increase the likelihood of an action potential occurring in the postsynaptic neuron, while IPSPs decrease that likelihood. These potentials result from the opening or closing of ion channels, leading to changes in the membrane potential of the postsynaptic cell.
Resting membrane potential is typically around -70mV and is maintained by the activity of ion channels that allow for the passive movement of ions across the cell membrane.
An increase in Na⁺ conductance would lead to an influx of sodium ions into the cell, causing the membrane potential to become more positive and move closer to the sodium equilibrium potential, which is typically around +60 mV. This depolarization could make the resting membrane potential less negative or even shift it above the threshold for action potential generation. Conversely, a decrease in Na⁺ conductance would reduce sodium influx, potentially stabilizing the resting membrane potential at a more negative value. Overall, changes in Na⁺ conductance directly influence the excitability of the neuron or muscle cell.
A false statement about a cell's resting membrane potential could be that it does not involve the movement of ions across the cell membrane. In reality, the resting membrane potential is primarily due to the unequal distribution of ions, such as sodium and potassium, across the membrane, maintained by ion channels and pumps.
Equilibrium potential is referring to the equilibrium (or balance) established between the forces of diffusion and electrical forces specific to each ion. For example, the equilibrium potential for Potassium, K+, in a cell with a semi permeable membrane is -80mV or Ek+=80mV. The membrane potential, on the other hand, refers to the voltage across the membrane at anytime and takes into account a range of equilibrium potentials such as Potassium, Sodium etc.
Neurotransmitters that bind to the postsynaptic membrane generally generate a postsynaptic potential, which can be either excitatory (EPSP) or inhibitory (IPSP). EPSPs increase the likelihood of an action potential occurring in the postsynaptic neuron, while IPSPs decrease that likelihood. These potentials result from the opening or closing of ion channels, leading to changes in the membrane potential of the postsynaptic cell.
The fall in membrane potential in cells is caused by the movement of ions across the cell membrane, specifically the exit of positively charged ions like potassium or the entry of negatively charged ions like chloride. This disrupts the balance of charges inside and outside the cell, leading to a decrease in membrane potential.
A substance that decreases membrane permeability to sodium would decrease the generation of a nerve impulse. This is because sodium ions play a crucial role in depolarizing the membrane and initiating nerve impulses. By reducing sodium influx into the cell, the ability of the neuron to generate an action potential would be diminished.
A decrease in the surface area of the respiratory membrane will result in a decrease in gas exchange.
Increasing extracellular potassium (K+) reduces the concentration gradient between the inside and outside of the cell, leading to a decrease in the driving force for potassium to exit the cell. As a result, the membrane potential becomes less negative (depolarizes) because the resting membrane potential is influenced by the relative permeability of the membrane to potassium ions. This outcome aligns with the prediction that an increase in extracellular potassium would diminish the negativity of the membrane potential, confirming the importance of K+ concentration gradients in maintaining resting membrane potential.
The resting potential of a cell is the membrane potential when the cell is at rest, typically around -70 millivolts. Membrane potential refers to the difference in electrical charge across the cell membrane. Resting potential is a type of membrane potential that is maintained when the cell is not actively sending signals.
The greater influx of sodium ions results in membrane depolarization. This is because sodium ions carry a positive charge, which leads to a decrease in the membrane potential towards zero or a positive value.
Leaking of potassium across the membrane will lead to a decrease in the intracellular potassium concentration, causing the neuron to become hyperpolarized (more negative). This will make it more difficult for the neuron to reach threshold and fire an action potential.
It would decrease the probability of generating a nerve impulse. When a neuron is activiated by a threshold stimulus, the membrane briefly becomes more permeable to sodium. If the permeability is decreased, it will be more difficult for the sodium ions to rush into the cell.
A decrease in cholesterol can increase membrane fluidity because cholesterol helps to stabilize the cell membrane and reduce its fluidity. When cholesterol levels decrease, the cell membrane becomes more fluid and flexible, which can impact the overall structure and function of the cell.
Resting membrane potential is typically around -70mV and is maintained by the activity of ion channels that allow for the passive movement of ions across the cell membrane.
The Nernst potential refers to the reversal potential of the membrane potential at which there is no net flow of a particular number of ion from one side of the membrane to another.