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.
Sensory neurons are somewhat unique, having an axon that extends to the periphery and another axon that extends into the central nervous system via the dorsal root (figure 3). The cell body of this neuron is located in the dorsal root ganglion or one of the sensory ganglia of sensory cranial nerves. Both the peripheral and the central axon attach to the neuron at the same point, and these sensory neurons are called pseudounipolar neurons.