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 (afferent neurons) are unipolar, bipolar, or multipolar shaped cells that conduct action potentials toward or into the central nervous system. They carry somatic nervous system signals from the skin, joints, skeletal muscles, sensory organs (eyes, ears, mouth, and nose).