Forebrain, Midbrain and Hindbrain – Easy NEET Notes
18.4.1 Forebrain
Forebrain consists of:
- Cerebrum
- Thalamus
- Hypothalamus
These are the major parts of the forebrain.
Cerebrum
- Cerebrum is the largest part of the human brain.
- It controls:
- Thinking
- Intelligence
- Memory
- Learning
- Speech
- Voluntary actions
Cerebral Hemispheres
- A deep groove divides the cerebrum into:
- Left cerebral hemisphere
- Right cerebral hemisphere
Corpus Callosum
- Both hemispheres are connected by nerve fibres called:
- Corpus callosum
- It allows communication between the two hemispheres.
Cerebral Cortex
- Outer layer of cerebrum is called the cerebral cortex.
- It is highly folded to increase surface area.
- It appears grey due to presence of neuron cell bodies.
- Therefore, it is called Grey Matter.
Functions of Cerebral Cortex
It contains:
- Motor areas → control voluntary movements.
- Sensory areas → receive sensory impulses.
- Association areas → involved in:
- Memory
- Intelligence
- Communication
- Interpretation of sensations
White Matter
- Inner region of cerebrum contains myelinated nerve fibres.
- Myelin gives white appearance.
- Therefore, inner part is called White Matter.
Easy Difference
| Grey Matter | White Matter |
|---|---|
| Outer region | Inner region |
| Contains neuron cell bodies | Contains myelinated fibres |
| Grey in colour | White in colour |
Thalamus
- Cerebrum surrounds the thalamus.
- Thalamus acts as a:
- Major coordinating centre
- Relay station for sensory and motor signals
Functions
- Receives sensory impulses
- Transfers impulses to cerebrum
- Helps in motor coordination
Hypothalamus
- Located at the base of thalamus.
- It controls many important body activities.
Functions of Hypothalamus
- Controls body temperature
- Controls hunger and thirst
- Regulates sleep and emotions
- Contains neurosecretory cells
Hypothalamic Hormones
- Neurosecretory cells produce:
- Hypothalamic hormones
- These hormones regulate pituitary gland functions.
Limbic System
- Inner parts of cerebrum with structures like:
- Amygdala
- Hippocampus
- Together form the Limbic System.
Functions
- Controls emotions:
- Fear
- Anger
- Pleasure
- Excitement
- Involved in:
- Motivation
- Memory
- Sexual behaviour
18.4.2 Midbrain
- Midbrain lies between:
- Forebrain
- Hindbrain
Cerebral Aqueduct
- A canal called cerebral aqueduct passes through the midbrain.
Corpora Quadrigemina
- Dorsal side of midbrain has four rounded swellings called:
- Corpora quadrigemina
Functions of Midbrain
- Controls visual reflexes
- Controls auditory reflexes
- Helps in movement of eyes and head
18.4.3 Hindbrain
Hindbrain consists of:
- Pons
- Cerebellum
- Medulla oblongata
Pons
- Contains nerve fibre tracts.
- Connects different regions of brain.
Functions
- Relays signals
- Helps in respiration control
Cerebellum
- Surface is highly folded.
- Provides space for more neurons.
Functions
- Maintains body balance
- Coordinates muscular activity
- Maintains posture
- Ensures smooth voluntary movements
NEET Point
- Damage to cerebellum causes:
- Loss of balance
- Irregular movements
Medulla Oblongata
- Connected to spinal cord.
Functions
Controls involuntary activities:
- Breathing
- Heartbeat
- Blood pressure
- Gastric secretions
Brain Stem
Brain stem includes:
- Midbrain
- Pons
- Medulla oblongata
Functions of Brain Stem
- Connects brain with spinal cord
- Controls basic life processes
- Pathway for nerve impulses
Quick NEET Revision Points
Forebrain
- Largest and most advanced part
- Includes cerebrum, thalamus, hypothalamus
Cerebrum
- Intelligence and memory centre
- Two hemispheres connected by corpus callosum
Grey Matter
- Outer cortex
- Contains neuron cell bodies
White Matter
- Inner region
- Contains myelinated fibres
Thalamus
- Relay centre for sensory impulses
Hypothalamus
- Controls temperature, hunger, thirst
Limbic System
- Emotional brain
Midbrain
- Visual and auditory reflexes
Cerebellum
- Balance and coordination
Medulla
- Controls involuntary activities
Brain Stem
- Midbrain + Pons + Medulla
Mnemonics for NEET
Forebrain Parts
“CTH”
- C → Cerebrum
- T → Thalamus
- H → Hypothalamus
Hindbrain Parts
“PCM”
- P → Pons
- C → Cerebellum
- M → Medulla
Brain Stem
“MPM”
- Midbrain
- Pons
- Medulla
Human Neural System diagram showing CNS, PNS and neuron structure for Class 11 Biology and NEET preparation.
CBSE Class 11 Biology – Neural System Question Bank
Chapter: Neural Control and Coordination
VERY SHORT ANSWER QUESTIONS (1 MARK)
Q1. What is the structural and functional unit of nervous system?
Answer: Neuron.
Q2. Name the two divisions of human neural system.
Answer:
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
Q3. What does CNS include?
Answer: Brain and spinal cord.
Q4. Define ganglia.
Answer: Clusters of neuron cell bodies outside CNS are called ganglia.
Q5. What are afferent fibres?
Answer: Fibres carrying impulses from body organs to CNS.
Q6. What are efferent fibres?
Answer: Fibres carrying impulses from CNS to organs or muscles.
Q7. Which nervous system controls voluntary actions?
Answer: Somatic nervous system.
Q8. Which nervous system controls involuntary activities?
Answer: Autonomic nervous system.
Q9. Name the two divisions of autonomic nervous system.
Answer:
- Sympathetic nervous system
- Parasympathetic nervous system
Q10. What is a nerve net?
Answer: A network of interconnected neurons found in Hydra.
SHORT ANSWER QUESTIONS (2–3 MARKS)
Q1. Differentiate between CNS and PNS.
| CNS | PNS |
|---|---|
| Includes brain and spinal cord | Includes nerves associated with CNS |
| Main control centre | Connects CNS to body organs |
| Processes information | Transmits impulses |
Q2. Differentiate between afferent and efferent fibres.
| Afferent Fibres | Efferent Fibres |
|---|---|
| Carry impulses to CNS | Carry impulses from CNS |
| Sensory nerves | Motor nerves |
| Receptors → CNS | CNS → Effectors |
Q3. Write functions of sympathetic nervous system.
Answer:
- Prepares body during stress.
- Increases heartbeat.
- Dilates pupil.
- Raises blood pressure.
- Called “fight or flight” system.
Q4. Write functions of parasympathetic nervous system.
Answer:
- Conserves body energy.
- Slows heartbeat.
- Stimulates digestion.
- Helps body relax.
- Called “rest and digest” system.
Q5. Name the three parts of neuron and write their functions.
| Part | Function |
|---|---|
| Cell body | Controls metabolic activities |
| Dendrites | Receive impulses |
| Axon | Carries impulses away |
LONG ANSWER QUESTIONS (5 MARKS)
Q1. Explain the divisions of human nervous system.
Answer:
The human nervous system is divided into:
1. Central Nervous System (CNS)
- Includes brain and spinal cord.
- Main control and coordination centre.
- Processes information.
2. Peripheral Nervous System (PNS)
- Includes all nerves connected to CNS.
- Divided into:
- Afferent fibres
- Efferent fibres
Further divisions of PNS
(a) Somatic Nervous System
- Controls voluntary actions.
- Connected to skeletal muscles.
(b) Autonomic Nervous System
- Controls involuntary activities.
- Divided into:
- Sympathetic nervous system
- Parasympathetic nervous system
Q2. Describe the structure of neuron with labelled points.
Answer:
Neuron is the structural and functional unit of nervous system.
Parts of neuron:
1. Cell Body
- Contains nucleus and cytoplasm.
- Contains Nissl’s granules.
- Controls cell activities.
2. Dendrites
- Short branched fibres.
- Receive nerve impulses.
3. Axon
- Long fibre.
- Carries impulses away from cell body.
Direction of impulse:
Dendrite → Cell body → Axon
MULTIPLE CHOICE QUESTIONS (MCQs)
Q1. Structural and functional unit of nervous system is:
A. Axon
B. Neuron
C. Muscle fibre
D. Ganglia
Answer:
✅ B. Neuron
Q2. Hydra possesses:
A. Brain
B. Spinal cord
C. Nerve net
D. Ganglion
Answer:
✅ C. Nerve net
Q3. CNS consists of:
A. Brain and nerves
B. Brain and spinal cord
C. Nerves and ganglia
D. Axon and dendrites
Answer:
✅ B. Brain and spinal cord
Q4. Afferent fibres are:
A. Motor fibres
B. Sensory fibres
C. Mixed nerves
D. Connector fibres
Answer:
✅ B. Sensory fibres
Q5. Fight or flight response is controlled by:
A. Parasympathetic NS
B. Somatic NS
C. Sympathetic NS
D. CNS
Answer:
✅ C. Sympathetic NS
Q6. Nissl’s granules are present in:
A. Cell body
B. Axon
C. Myelin sheath
D. Synapse
Answer:
✅ A. Cell body
Q7. Dendrites function ki to:
A. Carry impulses away
B. Receive impulses
C. Protect neuron
D. Form myelin sheath
Answer:
✅ B. Receive impulses
Q8. Somatic nervous system controls:
A. Digestion
B. Heartbeat
C. Voluntary actions
D. Blood pressure
Answer:
✅ C. Voluntary actions
ASSERTION AND REASON QUESTIONS
Q1.
Assertion (A):
Afferent fibres are sensory fibres.
Reason (R):
They carry impulses from organs to CNS.
Answer:
✅ Both A and R are true and R is the correct explanation of A.
Q2.
Assertion (A):
Sympathetic nervous system slows heartbeat.
Reason (R):
It conserves energy during rest.
Answer:
❌ Both Assertion and Reason are false.
Q3.
Assertion (A):
Neuron is the structural and functional unit of nervous system.
Reason (R):
Neuron can transmit nerve impulses.
Answer:
✅ Both A and R are true and R is the correct explanation.
CASE STUDY QUESTIONS
Case Study 1
A student accidentally touches a hot pan and immediately withdraws his hand. The sensory receptors send impulses to the CNS, and the CNS sends commands to muscles.
Questions:
Q1. Which fibres carry impulses to CNS?
Answer: Afferent fibres.
Q2. Which fibres carry impulses from CNS to muscles?
Answer: Efferent fibres.
Q3. Which system controls skeletal muscles?
Answer: Somatic nervous system.
Q4. Name the control centre of body.
Answer: CNS.
STATEMENT-BASED QUESTIONS
Q1. Identify True/False
(i) CNS includes brain and spinal cord.
✅ True
(ii) Parasympathetic nervous system prepares body for emergency.
❌ False
(iii) Axon receives impulses.
❌ False
(iv) Hydra has nerve net.
✅ True
(v) Dendrites are short branched fibres.
✅ True
MATCH THE COLUMN
Q1.
| Column A | Column B |
|---|---|
| (A) Afferent fibres | (i) Carry impulses from CNS |
| (B) Efferent fibres | (ii) Receive impulses |
| (C) Dendrites | (iii) Carry impulses to CNS |
| (D) Axon | (iv) Carry impulses away |
Answers:
A → iii
B → i
C → ii
D → iv
Q2.
| Column A | Column B |
|---|---|
| (A) Sympathetic NS | (i) Rest and digest |
| (B) Parasympathetic NS | (ii) Fight or flight |
| (C) Somatic NS | (iii) Voluntary control |
| (D) CNS | (iv) Brain and spinal cord |
Answers:
A → ii
B → i
C → iii
D → iv
IMPORTANT CBSE/NEET ONE-LINERS
- Neuron is the structural and functional unit of nervous system.
- Hydra possesses a nerve net.
- CNS consists of brain and spinal cord.
- Sensory fibres are afferent fibres.
- Motor fibres are efferent fibres.
- Sympathetic system = fight or flight.
- Parasympathetic system = rest and digest.
- Dendrites receive impulses.
- Axon carries impulses away from cell body.
- Internal Links
- Cell Structure and Function Notes
- Animal Kingdom NEET Notes
- Structural Organisation in Animals
- Chemical Coordination and Integration
- Locomotion and Movement Notes
- Biomolecules Class 11 Notes
- Breathing and Exchange of Gases
- Body Fluids and Circulation
- Neural Control and Coordination MCQs
- Human Physiology Complete Notes
- Nissl’s granules help in protein synthesis.
Internal Links
Cell Structure and Function Notes
Animal Kingdom NEET Notes
Structural Organisation in Animals
Chemical Coordination and Integration
Locomotion and Movement Notes
Biomolecules Class 11 Notes
Breathing and Exchange of Gases
Body Fluids and Circulation
Neural Control and Coordination MCQs
Human Physiology Complete Notes
HUMAN BRAIN
│
┌─────────────────────┼─────────────────────┐
│ │ │
FOREBRAIN MIDBRAIN HINDBRAIN
│ │ │
│ │ ┌──────────┼──────────┐
│ │ │ │ │
│ │ PONS CEREBELLUM MEDULLA
│ │
│ │
┌──────┼───────────┐ │
│ │ │ │
CEREBRUM THALAMUS HYPOTHALAMUS
│ │ │
│ │ │
│ │ ├─────────────────────────────┐
│ │ │ │
│ │ Controls: Neurosecretory
│ │ • Body temperature cells secrete
│ │ • Hunger hypothalamic
│ │ • Thirst hormones
│ │ • Emotions
│ │
│ Sensory & motor
│ relay centre
│
├──────────────────────────────────────────────────────┐
│ │
Two cerebral hemispheres Limbic system
│ │
│ │
Connected by Includes:
CORPUS CALLOSUM • Amygdala
│ • Hippocampus
│
├───────────────────────────────┐
│ │
GREY MATTER WHITE MATTER
│ │
Outer cerebral cortex Inner myelinated fibres
│ │
Contains neuron Gives white appearance
cell bodies
│
├──────────────────────────────────────────────┐
│ │ │
Motor areas Sensory areas Association areas
│ │ │
Voluntary Receive sensory Memory, learning,
movements impulses intelligence,
communication
────────────────────────────────────────────────────────────
MIDBRAIN
│
├── Cerebral aqueduct present
│
├── Corpora quadrigemina
│ • Four rounded lobes
│
└── Functions
• Visual reflexes
• Auditory reflexes
────────────────────────────────────────────────────────────
PONS
│
├── Connects brain regions
└── Helps in respiration
CEREBELLUM
│
├── Highly folded surface
├── Coordinates muscles
├── Maintains posture
└── Maintains balance
MEDULLA OBLONGATA
│
├── Connected to spinal cord
└── Controls involuntary actions
• Breathing
• Heartbeat
• Blood pressure
• Gastric secretion
────────────────────────────────────────────────────────────
BRAIN STEM
│
├── Midbrain
├── Pons
└── Medulla oblongata
Function:
• Connects brain and spinal cord
• Controls basic life activities
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