Academy of Doctors of Audiology. Advanced Beneficiary Notice FAQ. The Advanced Beneficiary Notice of Noncoverage (ABN) is a Medicare document that is used to notify Medicare beneficiaries of their potential financial responsibilities prior to the rendering of a service or the dispensing of an item.
primary sensory neuron. A sensory neuron that is the first in an afferent pathway, beginning at the receptor and ending at a synapse with a secondary sensory neuron, often within a nucleus of the central nervous system. One common type is the pseudounipolar neuron. 1  pseudounipolar neuron.  secondary sensory neuron.
A sensory neuron synapses on a motor neuron. The axon of the sensory neuron is very close to the dendrite of the motor neuron. The axon of the sensory neuron sends a chemical signal called a neurotransmitter to the dendrite of the motor neuron.