The central nervous system comprises of

Step 1: Analyze the question The question asks which parts make up the central nervous system (CNS).

Step 2: Explain the concept The nervous system has two main divisions:

1. Central Nervous System (CNS): the control centre. It is made up of the brain and the spinal cord.
2. Peripheral Nervous System (PNS): the nerves that connect the CNS to the rest of the body. It includes: • Somatic nervous system: controls voluntary actions (e.g., moving your hand). • Autonomic nervous system: controls involuntary actions (e.g., heartbeat, digestion). It has sympathetic and parasympathetic parts.

Step 3: Solve by elimination

• A. Brain and somatic: Wrong. The somatic system belongs to the PNS.
• B. Brain and spinal cord: Correct. These are the two components of the CNS.
• C. Spinal cord and somatic: Wrong. Somatic is part of the PNS.
• D. Brain only: Incomplete. It leaves out the spinal cord.

Step 4: Answer The central nervous system comprises the brain and spinal cord, which is option B.

Exam tip: Remember CNS = Core: the brain and spinal cord sit in the protected core of the body (skull and vertebral column). Anything that branches out to the limbs and organs, such as somatic and autonomic nerves, belongs to the Peripheral system.