Pretest-posttest designs grew from the simpler posttest only designs, and address some of the issues arising with assignment bias and the allocation of participants to groups. One example is education, where researchers want to monitor the effect of a new teaching method upon groups of children.
The neuromuscular junction (NMJ) is the site of communication between motor nerve axons and muscle fibres.It is composed of four specialised cell types: motor neurons, Schwann cells, muscle fibres and the recently discovered kranocytes.he neuromuscular junction (NMJ) is the site of communication between motor nerve axons and muscle fibres.
Synaptic cleft is the space between the motor end plate (muscle fiber part) and synaptic end bulb (motor neuron part) of the neuromuscular junction. It is 20 to 30 nanometers wide. Because of this cleft, the connection between the motor neuron and the muscle fiber is not continuous and there is a break.ifference between synapse and neuromuscular junction: Synapses and neuromuscular junctions are physiologically the same, however, the neuromuscular junction is a specific type of synapse that occurs between motor neuron and muscle fiber.