Why is it advantageous for a person that the impulse passes through reflex arc first before relayed to brain?

The transmission of sensory information through the reflex arc before reaching the brain offers several advantages:

Speed of Response: Reflex actions are faster than voluntary movements because the signal does not have to travel all the way to the brain and back. For instance, when you touch a hot object, the reflex arc allows you to withdraw your hand almost immediately, protecting you from further damage.

Protection and Avoidance: Reflexes help protect the body from harmful stimuli or potentially dangerous situations. For example, the knee-jerk reflex helps prevent the knee from buckling when it's suddenly extended.

Efficient and Energy-Conserving: Reflex arcs allow the body to respond to certain stimuli without conscious thought or the need to engage higher brain functions. This conserves energy and enables rapid, automatic responses.

Predictable and Consistent Responses: Reflexes are stereotyped and predictable responses to specific stimuli. This consistency ensures reliable and appropriate reactions to environmental changes or hazards.

Adaptation to Environment: Reflex arcs contribute to the body's adaptation to the environment by allowing for quick adjustments to certain stimuli. These responses can be modified and fine-tuned through learning and experience.

Simple Circuit: The reflex arc consists of a relatively simple neural pathway involving the sensory neuron, the spinal cord (or brainstem), and the motor neuron. This simplicity contributes to the efficiency and speed of reflex responses.

Support for Voluntary Movement: While reflex actions serve as automatic responses to stimuli, they also provide a foundation for more complex voluntary movements. They help in coordinating muscle activity and establishing sensory-motor connections.

Redundancy and Backup Mechanisms: The reflex arc pathway acts as a backup mechanism for motor responses in case the brain is incapacitated or the neural pathways to the brain are damaged.

Integration with Brain Functions: Although the initial response occurs at the spinal or brainstem level, the brain eventually receives the sensory information from the reflex and processes it, allowing for learning, memory formation, and conscious control over future responses.

Overall, the reflex arc's ability to process and respond to sensory information quickly and automatically provides numerous advantages for an individual's survival, protection, and efficient functioning in the environment.