Ace the Ambulatory Care Nurse Exam 2025 – Blaze Your Trail in Healthcare!

The central nervous system (CNS) is composed exclusively of the brain and spinal cord. This system is responsible for processing sensory information and coordinating responses throughout the body. The brain serves as the control center, interpreting signals and allowing for complex functions such as thought, emotion, and memory. The spinal cord acts as a major pathway for transmitting messages between the brain and the rest of the body, facilitating reflex actions and sensory data relay.

The other options include elements that are not part of the central nervous system. For instance, the sympathetic nervous system is a component of the peripheral nervous system, which manages involuntary body functions. While nerve cells are essential for nervous system function, they are part of both the central and peripheral systems and do not constitute the CNS by themselves. Lastly, the heart and lungs do not belong to the central nervous system; they are part of the cardiovascular and respiratory systems, respectively. Understanding the precise definition and components of the central nervous system is crucial for recognizing its role in overall health and patient care.