Question

Which is the correct sequence of the components of a reflex arc?

• A. Receptors $\to$ muscles $\to$ sensory neuron $\to$ motor neuron $\to$ spinal cord
• B. Receptors $\to$ motor neuron $\to$ spinal cord $\to$ sensory neuron $\to$ muscle
• C. Receptors $\to$ spinal cord $\to$ sensory neuron $\to$ motor neuron $\to$ muscle
• D. Receptors $\to$ sensory neuron $\to$ spinal cord $\to$ motor neuron $\to$ muscle

Answer 1

Answer: (D)

The reflex arc is a part of the peripheral nervous system and is responsible for actions performed in response to certain stimuli, such as pulling a hand away from a hot object. Its components include a receptor that receives the initial stimulus, such as skin, muscles or organs, a sensory neuron that carries the signal to the central nervous system (the spinal cord), an interneuron that relays the information to the central nervous system, and one or more motor neurons that relay the information to the final component of the arc, the effector. The effector could be a muscle, a gland or both.

Therefore, the correct answer is option D.