Nervous Tissue and Membrane Potentials #2

These flashcards cover key terms and concepts related to the structure and function of nervous tissue, membrane potentials, and the generation of action potentials.

Neuron

Excitable cells that initiate and transmit nerve impulses.

Glial Cells

Non-excitable cells that support and protect neurons.

Membrane Potential

The voltage difference across a cell membrane due to charge separation.

Resting Membrane Potential (RMP)

The membrane potential of a neuron at rest, typically around -70mV.

Graded Potential

A localized change in membrane potential in response to stimulus, which can be depolarizing or hyperpolarizing.

Action Potential

A significant fluctuation in membrane potential characterized by depolarization followed by repolarization.

Threshold Potential

The membrane potential that must be reached for an action potential to be triggered, usually around -55mV.

Sodium-Potassium Pump

A pump that maintains the concentration gradient of Na+ and K+ across the plasma membrane.

All-or-None Principle

The principle that action potentials occur at full amplitude or not at all, depending on whether the threshold is reached.

Equilibrium Potential

The membrane potential at which the concentration gradient for an ion is balanced by its electrical gradient.

Excitatory Postsynaptic Potential (EPSP)

A graded potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A graded potential that makes a neuron less likely to fire an action potential.

Voltage-gated Channels

Ion channels that open or close in response to changes in membrane potential and are crucial for action potentials.

Chemically gated Channels

Ion channels that open in response to the binding of neurotransmitters.

Depolarization

The process during an action potential where the membrane potential becomes more positive.

Repolarization

The process during an action potential where the membrane potential returns to resting levels.

Hyperpolarization

A change in membrane potential that makes it more negative than the resting potential.

Myelin Sheath

A fatty layer that insulates axons and increases the speed of nerve impulse conduction.