Which statement best describes the primary function of the central nervous system (CNS)?

• A. It produces red and white blood cells and regulates blood clotting.
• B. It generates hormones and releases them into the blood to regulate long-term body processes.
• C. It primarily transports oxygen and nutrients to tissues through the bloodstream.
• D. It integrates sensory information, processes it, and coordinates motor output and higher functions such as cognition and emotion.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the components of the central nervous system (CNS), which include the brain and spinal cord. These structures are responsible for processing and integrating information.
2. Step 2: Recognize that the CNS receives sensory input from the peripheral nervous system, processes this information, and then sends out motor commands to muscles and glands.
3. Step 3: Identify that the CNS is also involved in higher functions such as cognition (thinking, memory), emotion, and coordination of complex behaviors.
4. Step 4: Compare the given options by matching their descriptions to the known functions of the CNS. For example, blood cell production and hormone generation are functions of other systems (e.g., skeletal and endocrine systems).
5. Step 5: Conclude that the statement describing the CNS as integrating sensory information, processing it, and coordinating motor output and higher functions best captures its primary role.