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.
The interface between a motor neuron and muscle fiber is a specialized synapse called the neuromuscular junction. Upon adequate stimulation, the motor neuron releases a flood of neurotransmitters that bind to postsynaptic receptors and triggers a response in the muscle fiber which leads to muscle movement.November 2012). A motor neuron (or motoneuron) is a nerve cell (neuron) whose cell body is located in the spinal cord and whose fiber (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.