High School

Which one of the following is the correct sequence for a regulatory reflex arc?

A. stimulus, effector, afferent pathway, integrating center, efferent pathway, receptor
B. stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector
C. stimulus, receptor, efferent pathway, integrating center, afferent pathway, effector
D. stimulus, effector, efferent pathway, integrating center, afferent pathway, receptor
E. effector, efferent pathway, integrating center, afferent pathway, receptor, stimulus

Answer :

The correct sequence for a regulatory reflex arc is option (b): stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector.

In a regulatory reflex arc, the process is as follows:

  1. Stimulus: A shift in the surroundings that prompts a reaction is called a stimulus.
  2. Receptor: The area of the body called a receptor is where a stimulus is detected or received. For instance, receptors found in the skin, eyes, or hearing.
  3. Afferent Pathway: The path through which the receptor sends information towards the integrating center. This typically involves sensory neurons.
  4. Integrating Center: The control center where the signals are received, analyzed, and an appropriate response is determined. In humans, this is often the brain or spinal cord.
  5. Efferent Pathway: The path through which the integrating center sends signals to the effector to produce a response. This typically involves motor neurons.
  6. Effector: the location in the body where a reaction is produced. This can be a muscle, gland, or another organ that acts to restore homeostasis or produce an appropriate reaction to the stimulus.

Final answer:

The correct sequence for a regulatory reflex arc is 'b. stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector', which outlines the process from detecting a stimulus to responding to it.

Explanation:

Within the context of the nervous system and regulatory reflex arcs, the correct sequence of events after a stimulus is as follows:

  1. Stimulus: A change in the environment that triggers the reflex.
  2. Receptor: The site within the body that detects or receives the stimulus.
  3. Afferent pathway: The sensory neurons that carry the signal towards the central nervous system.
  4. Integrating center: Typically the brain or spinal cord where the information is processed and an appropriate response is determined.
  5. Efferent pathway: The motor neurons that carry the signal away from the central nervous system to the effector.
  6. Effector: The body site, such as a muscle or gland, where the response to the stimulus is generated.

So, the correct option from the given choices is 'b. stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector'.