which type of neuron does the sensory neuron synapse with in a monosynaptic reflex
Reflex arc When a reflex arc in an animal consists of only one sensory neuron and one motor neuron, it is defined as monosynaptic, referring to the presence of a single chemical synapse. In the case of peripheral muscle reflexes (patellar reflex, achilles reflex), brief stimulation to the muscle spindle results in contraction of the agonist or effector muscle. By contrast, in polysynaptic reflex pathways, one or more interneurons connect afferent (sensory) and efferent (motor) signals. All but the most simple reflexes are polysynaptic, allowing processing or inhibition of polysynaptic reflexes within the brain.
Sensory nerve A sensory nerve, also called an afferent nerve, is a nerve that carries sensory information toward the central nervous system (CNS). It is a cable-like bundle of the afferent nerve fibers coming from sensory receptors in the peripheral nervous system (PNS). A motor nerve carries information from the CNS to the PNS, and both types of nerve are called peripheral nerves.