Option 2 is the correct answer which depicts the correct circuit of a reflex arc. Let`s break down each component of the circuit to understand why this option is correct.
Receptor: The reflex arc begins with a receptor, which detects a stimulus. The receptor could be something like a sensory nerve ending that detects pain or pressure.
Sensory neuron: Once the receptor detects a stimulus, it sends the signal to the sensory neuron. The sensory neuron carries this signal towards the central nervous system (spinal cord or brain) for processing.
Spinal cord: In the case of a spinal reflex arc, the signal from the sensory neuron reaches the spinal cord. The spinal cord acts as a relay station and quickly processes the information.
Motor neuron: After being processed in the spinal cord, the signal is sent to a motor neuron. The motor neuron carries the response signal away from the spinal cord towards the effector.
Effector: The effector is the muscle or gland that carries out the response. It receives the signal from the motor neuron and produces the appropriate action, such as contracting or secreting a substance.
Therefore, option 2 accurately represents the correct circuit of a reflex arc, starting with the receptor, followed by the sensory neuron, spinal cord, motor neuron, and