BackStudy Guide: Muscular System 3/4
Terms in this set (27)
Voltage is the electrical potential difference between two points, representing stored energy that can cause current to flow.
Membrane potential is the voltage difference across a cell's plasma membrane due to ion distribution.
Electricity is the flow of electric charge, often carried by electrons or ions.
Leakage channels are ion channels that are always open, allowing ions to move down their concentration gradient.
Ligand-gated channels open or close in response to a specific chemical binding (ligand) to the channel.
Voltage-gated channels open or close in response to changes in membrane potential.
Resting membrane potential is the stable voltage across the membrane of a resting cell, typically around -70 mV in neurons.
Action potential is a rapid, temporary change in membrane potential that propagates along excitable cells.
Electrochemical gradient is the combined effect of ion concentration and electrical charge differences across a membrane.
Depolarization is the process where the membrane potential becomes less negative (more positive) than the resting potential.
Repolarization is the return of the membrane potential to the resting negative value after depolarization.
Action potential propagation is the movement of the action potential along the membrane of a neuron or muscle fiber.
Neuromuscular junction is the synapse between a motor neuron and a skeletal muscle fiber.
Synaptic bulb is the swollen end of a motor neuron axon that releases neurotransmitters.
Synaptic cleft is the small gap between the synaptic bulb and the motor end plate.
Motor end plate is the specialized region of the muscle fiber membrane at the neuromuscular junction.
Innervation is the supply of nerves to a specific body part, such as a muscle.
Acetylcholine is a neurotransmitter released at the neuromuscular junction to stimulate muscle contraction.
Acetylcholinesterase is the enzyme that breaks down acetylcholine in the synaptic cleft to terminate the signal.
Excitation is the process of generating an action potential in a muscle fiber in response to a stimulus.
End plate potential is the local depolarization of the motor end plate caused by acetylcholine binding.
Excitation-contraction coupling is the sequence linking muscle fiber excitation to contraction via calcium release.
Contraction cycle is the repeating sequence of events where myosin heads bind, pivot, and release actin to shorten muscle fibers.
Rigor mortis is the stiffening of muscles after death due to lack of ATP preventing myosin release from actin.
Creatine is a molecule stored in muscle cells used to regenerate ATP during short bursts of activity.
Creatine phosphate is a high-energy compound that donates a phosphate to ADP to quickly regenerate ATP.
Creatine kinase is the enzyme that catalyzes the transfer of a phosphate group from creatine phosphate to ADP.