Question

End plate junction is present between
A. Neuron and striated muscle
B. Neuron and neuron
C. Muscle and muscle
D. Both (b) and (c)

Answer 1

Hint: End plate junction is a chemical synapse junction. It helps the motor neuron to transmit a signal to the muscle fiber which causes muscle contraction. Nerves from the peripheral nervous system and central nervous system are linked with the muscle and work together.

Complete answer:
There is synaptic transmission at the end plate junction or neuromuscular junction when the action potential reaches the presynaptic terminal of the motor neuron. This activates the voltage-gated calcium channels to allow calcium ions to enter the neuron. These calcium ions bind with the sensor proteins on synaptic vessels which trigger vesicle fusion with the cell membrane and release neurotransmitters from the motor neuron into the synaptic cleft. In humans, this neurotransmitter is acetylcholine which diffuses across the synaptic cleft and binds to nicotinic acetylcholine receptors.
Terminal branch of the motor neuron is thus connected to the target muscle and the movement is facilitated with the help of secretion of acetylcholine. This leads to the muscle contraction and then relaxation with help in overall working of the muscles. The development of the neuromuscular junction requires signaling from both muscles and the neuron's terminal end. Presynaptic motor axons at the neuromuscular junction terminate 30 nanometers from the cell membrane or the sarcolemma of the muscle fibre. Invaginations at the sarcolemma junction are called post junctional folds, which help in increasing the surface area facing the synaptic cleft.

Hence, the correct option is A. Neuron and striated muscle.

Note:
Neuromuscular diseases are referred to any disorder that is associated with the synaptic transmission between motor neurons and a muscle cell. These diseases can be inherited or acquired by the person.