What is the Central Neural System (Brain and Spinal Cord)?
Biology · Neural Control and Coordination · NEET
The central neural system (CNS) is made of just two organs: the brain and the spinal cord. It is the site where the body processes information and controls the whole system, while the peripheral nerves only carry messages to and from it. Memory hook: "CNS = Central = only 2 parts, Brain + Cord."
The central neural system (CNS) has only two parts, the brain and the spinal cord, and is the site of processing and control; all other nerves belong to the peripheral neural system (PNS).
Your doubts, answered
Is the spinal cord part of the CNS or the PNS?
The spinal cord is part of the CNS. NCERT clearly states the CNS includes the brain and the spinal cord. A common mistake is to think nerves running in the body mean the cord is peripheral, but the PNS is only the nerves that connect to the brain and spinal cord, not the cord itself.
What are the only two parts of the central neural system?
Only two: the brain and the spinal cord. Nothing else is inside the CNS. If a question lists a third organ (like the heart or a gland), that option is wrong.
Are the meninges (dura mater, arachnoid, pia mater) part of the CNS?
The meninges are protective covering layers around the brain and spinal cord, not neural tissue of the CNS itself. In NEET, meninges are described as protection for the CNS. Watch out: a question may pair meninges with a non-CNS membrane like the pericardium (around the heart) to trap you.
Is the brainstem part of the brain in the CNS?
Yes. The brainstem is a region of the brain and connects the brain to the spinal cord. It consists of the midbrain, pons and medulla oblongata. Note: the cerebrum is NOT part of the brainstem; it belongs to the forebrain.
What is the main job of the CNS versus the PNS?
The CNS (brain + spinal cord) is the site of information processing and control. The PNS is only the wiring: afferent fibres bring impulses to the CNS and efferent fibres carry impulses out from the CNS to organs and muscles.
⚠️ The NEET trap ✗ The brainstem includes the medulla oblongata, pons and cerebrum. ✓ The brainstem consists of the midbrain, pons and medulla oblongata. The cerebrum is part of the forebrain, not the brainstem. 🧠 Brainstem = Mid + Pons + Medulla. Cerebrum stays in the forebrain.
Real NEET questions
NEET 2023 Phase 2
Brainstem of human brain consists of:
A · Thalamus, Hypothalamus and Corpora quadrigemina
B · Amygdala, Hippocampus and Corpus Callosum
C · Mid-brain, Pons and Medulla Oblongata ✓
D · Forebrain, Cerebellum and Pons
Solution: NCERT states three regions make up the brain stem: midbrain, pons and medulla oblongata. The brainstem connects the brain to the spinal cord. So option C is correct.
NEET 2024
Given below are two statements: Statement I: The cerebral hemispheres are connected by a nerve tract known as corpus callosum. Statement II: The brain stem consists of the medulla oblongata, pons and cerebrum. Choose the most appropriate answer.
A · Both Statement I and Statement II are incorrect.
B · Statement I is correct but Statement II is incorrect. ✓
C · Statement I is incorrect but Statement II is correct.
D · Both Statement I and Statement II are correct.
Solution: Statement I is correct: the two cerebral hemispheres are joined by the corpus callosum. Statement II is wrong: the brainstem is midbrain, pons and medulla oblongata, not cerebrum. The cerebrum is part of the forebrain. So only Statement I is correct.
ReNEET 2026
Which of the following is not a part of the human central neural system?
A · Arachnoid
B · Dura mater
C · Pia mater
D · Pericardium ✓
Solution: Arachnoid, dura mater and pia mater are the three meninges that protect the brain and spinal cord (the CNS). The pericardium is the membrane sac around the heart and has nothing to do with the central neural system, so it is the odd one out.
Solved Neural Control and Coordination NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
CNS stands for Central Neural System (also called the central nervous system). It is made of the brain and the spinal cord.
Why is the CNS called the site of information processing and control?
Because the brain and spinal cord receive incoming signals, process them, and send out control signals. The peripheral nerves only carry the messages; the real decision-making happens in the CNS.
How is the CNS protected?
The brain is protected by the skull and the spinal cord by the vertebral column. Both are also covered by three meninges: an outer dura mater, a thin middle arachnoid, and an inner pia mater in contact with the neural tissue.
What are the three major parts of the brain?
The brain is divided into the forebrain, the midbrain and the hindbrain. The forebrain has the cerebrum, thalamus and hypothalamus; the hindbrain has the pons, cerebellum and medulla oblongata.
Is the CNS the same as the PNS?
No. The CNS is only the brain and spinal cord. The PNS (peripheral neural system) is all the nerves connected to the CNS, carrying impulses to and from it using afferent and efferent fibres.
