Resting Membrane Potential and Neuromuscular Synapse

These flashcards encompass key terms and concepts related to resting membrane potential, excitation-contraction coupling, and neuromuscular junction physiology.

Resting Membrane Potential

The electrical potential difference across the membrane of a resting excitable cell, typically negative in value.

Excitable Cells

Cells that can generate and propagate action potentials, such as neurons and muscle cells.

Excitation/Contraction Coupling Time

The time required for the electrical excitation of a muscle cell to result in contraction.

Sodium/Potassium Pump

Also known as the Na+/K+ ATPase, it establishes ion gradients by moving 3 Na+ out of the cell and 2 K+ into the cell per ATP hydrolyzed.

Electrogenic Pump

A pump that contributes to the resting membrane potential by generating a charge difference across the membrane.

Potassium Leak Channels

Channels that allow passive movement of potassium ions out of the cell, contributing to the resting membrane potential.

Concentration Gradient

A difference in the concentration of ions across a membrane that drives ion movement.

Electrical Gradient

A difference in electrical charge across a membrane that influences the movement of ions.

Equilibrium Potential of Potassium

The membrane potential at which the concentration gradient and electrical gradient for potassium are balanced.

Sodium Leak Channels

Channels that allow passive movement of sodium ions into the cell, having a minimal effect on the resting membrane potential.

Pr-

Refers to negatively charged proteins that contribute to the resting membrane potential by influencing the electrical gradient.

Neuromuscular Junction (NMJ)

The synapse or junction where a motor neuron meets a muscle fiber, facilitating muscle contraction.

Axon Terminal

The endpoint of a neuron where neurotransmitters are released; also known as the terminal arborization.

Voltage-Gated Calcium Channels

Channels that open in response to an action potential, allowing calcium ions to enter the cell.

Exocytosis of Acetylcholine

The process triggered by calcium influx that releases acetylcholine into the synaptic cleft.

Acetylcholine (Ach) Diffusion

The movement of acetylcholine across the synaptic cleft towards the motor end plate.

Ligand-Gated Ion Channel

A channel that opens in response to the binding of a specific ligand, such as acetylcholine.

Motor End Plate

The specialized region of the muscle cell membrane with acetylcholine gated sodium ion channels.

Acetylcholinesterase

An enzyme that breaks down acetylcholine in the synaptic cleft, important for terminating the signal.