GROSS ANATOMY

Detailed explanation-1: -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.

Detailed explanation-2: -Definition/Introduction. The monosynaptic stretch reflex, or sometimes also referred to as the muscle stretch reflex, deep tendon reflex, is a reflex arc that provides direct communication between sensory and motor neurons innervating the muscle.

Detailed explanation-3: -This reflex begins inside the muscle spindle of the muscle, which detects both the amount and rate of muscle stretch.

Detailed explanation-4: -When the arc consists of one sensory and motor neuron, it is referred to as a monosynaptic reflex (with ‘monosynaptic’ referring to one synapse). Monosynaptic reflexes include, for example, the biceps and triceps reflexes, and patellar stretch reflex or knee jerk (see figure below).

Detailed explanation-5: -The doctor tapping your tendon is a test of the simple monosynaptic reflex, which consists of a sensor, a sensory neuron, a motor neuron, and a muscle. Once the sensory neuron is activated, an action potential travels along the sensory neuron to the spinal cord.