Which systems together constitute the complete human nervous system that coordinates and controls body activities?

Introduction / Context:
The nervous system is responsible for rapid communication, control, and coordination throughout the human body. It detects stimuli, processes information, and issues responses. Anatomically and functionally, the nervous system is divided into major components. This question asks which systems together make up the complete human nervous system.

Given Data / Assumptions:

• The human nervous system is generally divided into major subdivisions.
• Options include the central nervous system, peripheral nervous system, their combination, and none of the above.
• The task is to identify which combination is correct and complete.
• We assume the standard anatomical classification used in textbooks.

Concept / Approach:
The central nervous system (CNS) consists of the brain and spinal cord and serves as the main control and integration center. The peripheral nervous system (PNS) consists of all the nerves and ganglia outside the CNS, including cranial nerves and spinal nerves. The PNS carries sensory information to the CNS and motor commands away from the CNS to muscles and glands. Taken together, the CNS and PNS constitute the entire nervous system. Therefore, the correct approach is to recognize that neither the CNS nor the PNS alone is sufficient; both are required for a complete system.

Step-by-Step Solution:
Step 1: Recall that the central nervous system includes the brain and spinal cord. Step 2: Recall that the peripheral nervous system includes all nerves and ganglia located outside the brain and spinal cord. Step 3: Understand that the nervous system as a whole is described as CNS plus PNS. Step 4: Evaluate option A and option B individually and recognize that each represents only part of the total system. Step 5: Choose option C, which states that both central and peripheral nervous systems together make up the nervous system.

Verification / Alternative check:
Standard anatomy diagrams show a central core of brain and spinal cord labeled as CNS, with branching peripheral nerves labeled as PNS. Textbook definitions of the nervous system nearly always describe it as composed of the CNS and PNS. Clinical discussions about nervous system disorders also often classify conditions based on whether they affect central or peripheral components. All of this supports the answer that both systems together constitute the full nervous system.

Why Other Options Are Wrong:
Option A (Central nervous system): This is only part of the nervous system and excludes peripheral nerves that carry signals to and from the CNS.
Option B (Peripheral nervous system): This includes nerves and ganglia but not the central processing organs, the brain and spinal cord.
Option D (None of the above): This would imply that neither CNS, PNS, nor their combination describes the nervous system, which is clearly incorrect based on standard classification.

Common Pitfalls:
Some students may think of the brain and spinal cord as the entire nervous system because they are the most prominent structures, leading them to select only the CNS. Others may underestimate the importance of peripheral nerves. It is essential to remember that the nervous system requires both central processing units and peripheral communication lines to function properly.

Final Answer:
The complete human nervous system is made up of both the central nervous system and the peripheral nervous system.