What does an end plate potential represent?
End plate potentials (EPPs) are the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction. It represents the smallest possible depolarization which can be induced in a muscle.
What causes end plate potentials?
These tiny electrical events, called miniature end-plate potentials (MEPPs), or miniature postsynaptic potentials (MPSPs), are caused by the random release of single quanta of neurotransmitter from a resting presynaptic terminal.
What causes the motor end plate to depolarize?
Depolarization of the motor end plate occurs when both receptors bind acetylcholine, causing a conformational change in the channel complex, opening it to the inward flow of positive ions (Figure 19-2). Cholinergic receptors are concentrated at the motor end-plate region of the sarcolemma in normal skeletal muscle.
What happens at the motor end plate?
Neuromuscular junctions, also called motor end plates, are specialised chemical synapses formed at the sites where the terminal branches of the axon of a motor neuron contact a target muscle cell. It contains multiple mitochondria and synaptic vesicles where the transmitter acetylcholine is stored.
What is end plate potential Vs action potential?
The end-plate potential is a graded potential (it is not all-or-none) that propagates electrotonically to the neighboring patch of muscle fiber membrane where it initiates an action potential on the muscle much like it does on unmyelinated nerves.
Is end plate potential an action potential?
Where does the end plate potential occur quizlet?
End-plate potential (EPP) is the postsynaptic potential induced at the neuromuscular junction by the opening of the nicotinic acetylcholine receptor. -The EPP is a graded potential that partially depolarizes the membrane and can initiate an action potential in the muscle sarcolemma.
What is an end plate potential quizlet?
End-plate potential (EPP) is the postsynaptic potential induced at the neuromuscular junction by the opening of the nicotinic acetylcholine receptor. -The Acetylcholine receptor is a mixed-cation channel (simultaneous Na+ and K+).
Is end plate potential a graded potential?
Whats a motor end plate?
Medical Definition of motor end plate : the terminal arborization of a motor axon on a muscle fiber.
Is end plate potential monophasic?
The EPP is monophasic because external currents flow only toward the end-plate zone from adjacent regions.
What is the potential of the end plate?
End-plate potential. Written By: End-plate potential (EPP), chemically induced change in electric potential of the motor end plate, the portion of the muscle-cell membrane that lies opposite the terminal of a nerve fibre at the neuromuscular junction.
What is the shunting effect at the end plate?
The shunting effect at the end-plate limits the peak depolarization of the action potential at this location to near the -15 mV reversal potential of the synaptic conductance increase of the postsynaptic membrane. This effect can be seen in Figure 25 of Fatt and Katz (1951).
What causes end plate potentials in the neuromuscular junction?
Note the differences in the scales on the X- and Y-axes. Both are taken from recordings at the mouse neuromuscular junction. End plate potentials (EPPs) are the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction.
Why is the end plate membrane electrically polarized?
The end-plate membrane is electrically polarized, the inside being negative with respect to the outside because of an uneven distribution of ions.