Study Question Fourteen

• Q14. Correlate the structures of the nervous system to a reflex, and predict what would happen to a normal arc if any of the structures were missing.
• Structures of the Nervous System in a Reflex Arc

  The RECEPTORS detect a stimulus.

  The AFFERENT or SENSORY NEURONS carry the signal from the receptor to the spinal cord.

  The INTEGRATION CENTERS involve interneurons in the spinal cord which process the information.

  The EFFERENT or MOTOR NEURONS transmit the signal from the spinal cord to the effector.

  The EFFECTORS are muscles or glands that carry out the response.
• Missing Structures

  If the RECEPTORS are missing, the body might fail to detect the stimulus. Harmful stimuli could go unnoticed, preventing any reflex and increasing the risk of injury.
• Missing Structures

  If the AFFERENT or SENSORY NEURONS are missing, signals from the receptors wouldn't reach the spinal cord.
• Missing Structures

  If the INTEGRATION CENTERS are missing, there would be no processing of the signals. So a response wouldn't be generated.
• Missing Structures

  If the EFFERENT or MOTOR NEURONS are missing, the signal would not reach the muscles. There would be no movement.
• Missing Structures

  If the EFFECTORS are missing, the muscles or glands would be missing or damaged. There would be no physical response.