MCQ Detailed View

The spinal cord is a vital part of the central nervous system (CNS). It runs from the brainstem down through the vertebral column, protected by the bony structure of the spine. Its main function is to transmit signals between the brain and the rest of the body. However, the spinal cord also has the ability to control certain actions independently, without direct involvement of the brain. These actions are known as reflex activities.

Reflex activities are automatic, rapid, and involuntary responses to stimuli. For example, if you touch a hot object, your hand withdraws immediately without you consciously deciding to move it. This happens because the sensory nerve endings in your skin send signals to the spinal cord, which immediately processes the information and sends motor signals back to the muscles to contract. The brain becomes aware of the pain slightly later, but the reflex action has already occurred, protecting the body from injury.

This arrangement ensures that responses to dangerous stimuli are extremely fast, as involving the brain would take more time. Reflexes controlled by the spinal cord include the knee-jerk reflex, the withdrawal reflex, and other basic protective movements. These actions are critical for survival because they allow the body to react quickly in emergencies.

The spinal cord does not control higher mental functions such as thinking, memory, reasoning, or decision making — these are the responsibility of the cerebrum in the brain. It also does not directly control sexual activity, though it does play a role in transmitting signals related to body functions.

Therefore, the spinal cord mainly controls reflex activities, which are essential for quick and protective body responses.