ScienceCBSE Class 10 · Control and Coordination

Human Brain: Parts, Functions and Protection

Updated 14 October 2026 · Fact-checked

The brain is the main coordinating centre of the body. With the spinal cord it forms the central nervous system. The fore-brain thinks, senses and controls voluntary movements; the mid-brain and hind-brain control involuntary actions, with the medulla handling blood pressure, salivation and vomiting, and the cerebellum keeping posture and balance. A bony skull and a fluid cushion protect it.

Understand Human Brain and Its Protection

Organisation of the nervous system. The brain and the spinal cord together make up the central nervous system (CNS). They receive information from all parts of the body and integrate it. Communication between the CNS and the rest of the body is carried by the peripheral nervous system, made up of cranial nerves, which start from the brain, and spinal nerves, which start from the spinal cord. The spinal cord is not only for reflexes; it carries the information the brain thinks about, and messages back to the body.

Two ways the nervous system talks to muscles. One is the reflex arc. The other is voluntary action: writing, talking, moving a chair or clapping at the end of a programme are based on deciding what to do next, so the brain must send messages to muscles.

Three main regions of the brain.

Fore-brain: the main thinking part. It has regions that receive sensory impulses from receptors, with separate areas specialised for hearing, smell, sight and so on. Association areas interpret this sensory information by combining it with information from other receptors and with information already stored in the brain. A decision is then passed to motor areas that control voluntary muscles, such as our leg muscles. A separate part of the fore-brain has the centre associated with hunger, which gives the sensation of feeling full.
Mid-brain and hind-brain: control many involuntary actions, movements we do not control by thinking, such as heartbeat, breathing and digestion.
In the hind-brain, the medulla controls involuntary actions including blood pressure, salivation and vomiting.
Also in the hind-brain, the cerebellum is responsible for the precision of voluntary actions and for maintaining posture and balance. Walking in a straight line, riding a bicycle and picking up a pencil depend on it.

So the brain is responsible for thinking, regulating the heartbeat and balancing the body.

Protection. A delicate organ like the brain needs careful protection:

it sits inside a bony box, the skull (cranium);
inside this box, it is held within a fluid-filled balloon that absorbs shocks;
the spinal cord is protected by the vertebral column (backbone), the hard, bumpy structure you can feel down the middle of your back.

Putting it together. A stimulus (say, seeing a ball coming towards you) is detected by receptors in the eye, sent to the sight area of the fore-brain, interpreted in association areas, and a decision is sent through motor areas to muscles; the cerebellum makes the catching movement precise and keeps you balanced. Meanwhile the medulla keeps your heart beating and your blood pressure steady without any thought.

Human Brain and Its Protection: formulas and key facts

Nervous system organisation: $CNS = brain + spinal cord; PNS = cranial nerves + spinal nerves$; PNS links the CNS to the rest of the body.
Fore-brain functions: $thinking, sensory areas, association areas, motor areas, hunger centre$; Main thinking part; controls voluntary muscles.
Medulla (hind-brain): $blood pressure, salivation, vomiting$; Involuntary actions.
Cerebellum (hind-brain): $precision of voluntary actions, posture, balance$; Walking straight, cycling, picking up a pencil.
Protection: $skull (bony box) + fluid cushion; vertebral column for spinal cord$; Fluid gives shock absorption.

How to solve Human Brain and Its Protection questions

For brain questions, match each activity to the region that controls it.

1Decide if the action is thought-out (voluntary), automatic and continuous (involuntary) or a sudden response (reflex).
2Voluntary decision: fore-brain (sensory → association → motor areas).
3Precision, posture, balance: cerebellum.
4Blood pressure, salivation, vomiting: medulla; other involuntary actions: mid-brain and hind-brain.
5Feeling full: hunger centre in the fore-brain.
6For protection questions, name both the bone and the fluid for the brain, and the vertebral column for the spinal cord.
7For diagrams, label fore-brain (cerebrum), mid-brain, hind-brain (cerebellum, medulla, pons), and pituitary if asked.

Human Brain and Its Protection in real life

Each concept, met in an everyday situation. Read the situation, try the problem, then check the solution. The one-line hook is what to remember.

Cerebellum and fore-brain in voluntary actions

Suppose you are learning to ride a bicycle. At first you think about every move and wobble a lot; after a few weeks you can ride in a straight line while chatting with a friend.

Which parts of the brain are involved in deciding to ride and in keeping you balanced? Which part keeps your heart beating faster during the ride without your thinking about it?

Try it first, then show the solutionSolution

Deciding to start, steer and stop is voluntary, so it involves the fore-brain: sensory areas receive information from the eyes and ears, association areas interpret it, and motor areas send instructions to leg and arm muscles.
Keeping the body balanced and making movements precise is done by the cerebellum in the hind-brain; with practice, riding straight becomes smooth.
Heartbeat and breathing continue without conscious control: these involuntary actions are controlled by the mid-brain and hind-brain, and the medulla controls blood pressure.

Answer: Fore-brain for decisions and voluntary muscle control; cerebellum for balance and precision; mid-brain and hind-brain (medulla) for involuntary actions such as blood pressure and heartbeat.

Memory hook: Fore-brain decides, cerebellum balances, medulla keeps the body running.

Tricks to remember Human Brain and Its Protection

Short memory aids. Say each one aloud once, then use it on a question the same day.

Cerebellum = Coordination
C for Cerebellum, C for Cycling and Coordination: posture, balance, precision.
Use it when: Questions on balance or precise movement.
Medulla's BSV
Blood pressure, Salivation, Vomiting.
Use it when: Listing medulla functions.
Box, balloon, backbone
Brain in a bony box and fluid balloon; spinal cord in the backbone.
Use it when: Protection of the CNS.

Human Brain and Its Protection: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Posture and balance · 2 marks · Very short answerBoard level

Name the part of the brain that maintains posture and balance of the body. Name one other function of the same part and give an example.

Try it first, then show the solutionSolution

The cerebellum, in the hind-brain (1 mark).
It is responsible for the precision of voluntary actions, for example picking up a pencil or walking in a straight line (1 mark).

Answer: Cerebellum; precision of voluntary actions (e.g. picking up a pencil).

Example 2: CNS and PNS · 3 marks · Short answerBoard level

(a) What makes up the central nervous system and the peripheral nervous system? (b) What is the role of the peripheral nervous system? (c) How is the central nervous system protected?

Try it first, then show the solutionSolution

(a) CNS: brain and spinal cord. PNS: cranial nerves from the brain and spinal nerves from the spinal cord (1 mark).
(b) It allows communication between the CNS and all other parts of the body (1 mark).
(c) The brain is inside a bony box (skull) and a fluid-filled balloon that absorbs shocks; the spinal cord is protected by the vertebral column (1 mark).

Answer: (a) Brain + spinal cord; cranial + spinal nerves. (b) Links CNS with the body. (c) Skull and fluid; vertebral column.

Example 3: Fore-brain at work · 3 marks · Short answerHarder board level

Describe how the fore-brain processes information when you hear your name called and turn to look. Mention sensory, association and motor areas.

Try it first, then show the solutionSolution

Receptors in the ear send impulses to the area of the fore-brain specialised for hearing (sensory area) (1 mark).
Association areas interpret the sound by combining it with stored information (recognising your name) and with inputs from other receptors, and a decision to respond is made (1 mark).
Motor areas send impulses to voluntary muscles of the neck and eyes, which turn you towards the sound (1 mark).

Answer: Hearing area receives; association areas interpret and decide; motor areas move the neck and eye muscles.

Example 4: Match the activity · 5 marks · Long answerHarder board level

Name the part of the brain mainly responsible for each and say whether the action is voluntary or involuntary: (a) feeling that you have eaten enough, (b) vomiting, (c) threading a needle, (d) deciding to answer a question in class, (e) salivation.

Try it first, then show the solutionSolution

(a) Hunger centre in a separate part of the fore-brain; involuntary sensation (1 mark).
(b) Medulla in the hind-brain; involuntary (1 mark).
(c) Cerebellum gives the precision; voluntary action started by the fore-brain (1 mark).
(d) Fore-brain (thinking, motor areas); voluntary (1 mark).
(e) Medulla; involuntary (1 mark).

Answer: (a) Fore-brain hunger centre (b) Medulla (c) Cerebellum with fore-brain (d) Fore-brain (e) Medulla.

Example 5: Effects of damage · 3 marks · Short answerHOTS / competency

Predict the most likely effect if (a) the cerebellum of a person were injured, (b) the medulla were damaged. Explain why damage to the medulla is more life-threatening.

Try it first, then show the solutionSolution

(a) Loss of balance and posture; movements would lose precision, so walking straight or picking up small objects would be difficult (1 mark).
(b) Involuntary actions controlled by the medulla, such as blood pressure, salivation and vomiting, would be disturbed (1 mark).
The medulla controls involuntary functions the body needs continuously to stay alive, such as blood pressure; these cannot be replaced by conscious effort, while poor balance, though serious, does not directly stop vital processes (1 mark).

Answer: (a) Poor balance and imprecise movements. (b) Disturbed blood pressure and other involuntary actions; more dangerous because these are vital and automatic.

Where students lose marks in Human Brain and Its Protection

The slips examiners see most often, and what to write instead.

Mistake: Swapping cerebellum and medulla
Both are in the hind-brain.
Wrong working
Medulla maintains balance; cerebellum controls vomiting.
Right working
Cerebellum: posture, balance, precision. Medulla: blood pressure, salivation, vomiting.
Do this: Use the memory tricks 'Cerebellum = Coordination' and 'Medulla's BSV'.
Usually costs: 1 mark per function.
Mistake: Forgetting the spinal cord is part of the CNS
Students think only the brain is central.
Wrong working
CNS is the brain; spinal cord is peripheral.
Right working
CNS = brain + spinal cord; PNS = cranial and spinal nerves.
Do this: Learn both pairs together.
Usually costs: 1 mark.
Mistake: Incomplete protection answer
Only the skull is mentioned.
Wrong working
The brain is protected by the skull.
Right working
Skull plus a fluid-filled balloon that absorbs shocks; the spinal cord is protected by the vertebral column.
Do this: Give bone + fluid for the brain and the backbone for the spinal cord.
Usually costs: ½ to 1 mark.
Mistake: Vague fore-brain description
Students write only 'it is for thinking'.
Wrong working
Fore-brain helps us think.
Right working
Fore-brain has sensory areas, association areas and motor areas, and the hunger centre.
Do this: Name at least two kinds of area.
Usually costs: 1 mark in 3-mark answers.

Exam tips

Use the correct region names: fore-brain, mid-brain, hind-brain, cerebellum, medulla.
When asked to draw the brain, label at least cerebrum (fore-brain), mid-brain, cerebellum, medulla, pons and pituitary as in the NCERT figure.
Give an example with each function; examiners often award the example separately.
Distinguish voluntary, involuntary and reflex actions clearly before naming regions.
For protection, write 'fluid-filled balloon for shock absorption' as NCERT describes it.

Practice questions on Human Brain and Its Protection

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which part of the brain controls blood pressure, salivation and vomiting?
(a) cerebellum (b) medulla (c) fore-brain (d) pituitary
Hint
It is in the hind-brain and controls involuntary actions.
Answer
(b) medulla.
Q2 · 1 mark · Assertion-reasonHarder board level
Assertion (A): The fore-brain is the main thinking part of the brain.
Reason (R): The fore-brain has association areas where sensory information is interpreted together with stored information.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Hint
Thinking involves interpreting and deciding.
Answer
(a).
Q3 · 2 marks · Very short answerHarder board level
Suppose a patient can solve puzzles and walk in a straight line without trouble, but his blood pressure keeps swinging and he salivates far more than normal. (a) Which part of the brain is most likely affected? (b) Which two parts can you rule out from his normal abilities, and why?
Hint
Match each normal or abnormal ability to the region that controls it.
Answer
(a) The medulla in the hind-brain, which controls involuntary actions such as blood pressure and salivation (1 mark). (b) The fore-brain, since his thinking is normal, and the cerebellum, since his balance and the precision of his walking are normal (1 mark).
Q4 · 4 marks · Case-basedHOTS / competency
Read the passage and answer.
Suppose a cricketer is struck on the helmet by a fast ball. He is shaken but unhurt. The team doctor explains that the helmet adds to the protection the body already gives the brain.
(a) Name the two natural protections of the brain. (1 mark)
(b) What protects the spinal cord? (1 mark)
(c) After the hit, the cricketer feels unsteady and cannot walk in a straight line for a few minutes. Which part of the brain is probably affected, and what else might be affected if the same part were badly damaged? (2 marks)
Hint
Balance and precision come from the same region.
Answer
(a) The bony skull and the fluid-filled balloon around the brain that absorbs shocks. (b) The vertebral column (backbone). (c) The cerebellum (hind-brain); serious damage could also affect the precision of voluntary actions such as picking up objects and riding a bicycle, and posture.
Q5 · 3 marks · Short answerHOTS / competency
A person with damage to the hunger centre may eat too much or too little. In which region of the brain is this centre? Explain how this example shows that the brain controls sensations other than sight and hearing.
Hint
Feeling full is a sensation too.
Answer
The hunger centre is in a separate part of the fore-brain. Feeling that we have eaten enough is a sensation, like seeing or hearing, but it does not come from a sense organ such as the eye or ear; it is produced by a centre in the fore-brain. Damage there would upset the feeling of fullness, so eating would not be regulated properly.
Q6 · 3 marks · Short answerBoard level
Write any three differences between voluntary and involuntary actions, giving one example of each and the brain region involved.
Hint
Control, region, examples.
Answer
Voluntary actions are under conscious control, decided by thinking, and controlled by the fore-brain (e.g. writing). Involuntary actions are not under conscious control, go on without thinking, and are controlled by the mid-brain and hind-brain (e.g. heartbeat, salivation by the medulla). Voluntary actions can be started or stopped at will; involuntary ones cannot easily be controlled even if we try.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Two parts of the CNS?Show answer
Brain and spinal cord.
2.Which part contains the hunger centre?Show answer
Fore-brain.
3.What does the cerebellum control?Show answer
Precision of voluntary actions, posture and balance.
4.What protects the spinal cord?Show answer
Vertebral column.
5.What are cranial nerves?Show answer
Nerves of the peripheral nervous system arising from the brain.
6.Which regions control most involuntary actions?Show answer
Mid-brain and hind-brain.

Human Brain and Its Protection: frequently asked questions

What are the three main parts of the human brain?

Fore-brain, mid-brain and hind-brain. The fore-brain is the thinking part; the mid-brain and hind-brain control involuntary actions; the hind-brain includes the cerebellum and medulla.

What is the function of the cerebellum?

It makes voluntary actions precise and maintains posture and balance, for example when walking in a straight line or riding a bicycle.

What does the medulla control?

Involuntary actions including blood pressure, salivation and vomiting.

How is the brain protected?

It sits in a bony box (the skull) and is enclosed in a fluid-filled balloon that absorbs shocks.

What is the peripheral nervous system?

Cranial nerves from the brain and spinal nerves from the spinal cord, which connect the central nervous system with the rest of the body.