Send detailed notes on class 10 science ch control and co ordination
Class 10 Science chapter “Control and Coordination” is about how living organisms detect changes in their surroundings and respond to them. In plants and animals, this coordination happens through chemical signals and nervous signals.
1) Why control and coordination are needed
Living things constantly face changes in their environment. To survive, they need to:
- sense changes
- process information
- respond properly
This helps in:
- avoiding danger
- finding food
- maintaining body functions
- growing and reproducing normally
2) Coordination in animals
In animals, coordination mainly happens through:
- nervous system
- endocrine system (hormonal system)
A. Nervous system
The nervous system sends fast electrical signals called nerve impulses.
Main parts:
- Brain
- Spinal cord
- Nerves
Neuron
A neuron is the basic structural and functional unit of the nervous system.
Parts of a neuron:
- Dendrites: receive messages
- Cell body: contains nucleus
- Axon: carries impulse away from cell body
- Nerve ending / synapse: passes signal to next neuron or organ
How nerve impulses travel
- A stimulus is detected.
- Receptor cells generate a signal.
- The impulse travels through neuron.
- It reaches brain/spinal cord.
- Brain processes it.
- Response is sent to effector muscles or glands.
Synapse
A synapse is the gap between two neurons. The impulse crosses this gap using neurotransmitters.
3) Reflex action
A reflex action is a quick, automatic response to a stimulus without conscious thought.
Example:
- pulling hand away from a hot object
- blinking of eyes
- sneezing
Reflex arc
The path followed by nerve impulses in a reflex action is called a reflex arc.
Path:
Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector → Response
Importance of reflex action
- protects body from harm
- gives very fast response
- controlled mainly by spinal cord
4) Parts of the human nervous system
A. Central nervous system (CNS)
Consists of:
- Brain
- Spinal cord
B. Peripheral nervous system (PNS)
Consists of nerves connecting CNS to different body parts.
C. Autonomous nervous system
Controls involuntary actions like:
- heartbeat
- breathing
- digestion
5) The human brain
The brain is the control center of the body. It is protected by the skull and covered by meninges. It also has cerebrospinal fluid for protection.
Main parts of brain:
A. Forebrain
- largest part
- includes cerebrum
- controls:
- thinking
- memory
- intelligence
- voluntary actions
- sensory perception
B. Midbrain
- helps in visual and auditory reflexes
C. Hindbrain
Includes:
- cerebellum
- pons
- medulla oblongata
Functions:
- Cerebellum: balance and posture
- Pons: connects parts of brain
- Medulla oblongata: controls involuntary actions like breathing, heartbeat, blood pressure
6) Endocrine system
The endocrine system uses hormones instead of nerve impulses.
Hormones
Hormones are chemical messengers released by endocrine glands directly into blood.
Characteristics of hormones:
- transported through blood
- act on specific target organs
- slower than nerves but effects last longer
7) Major endocrine glands and hormones
A. Pituitary gland
- called the master gland
- controls other endocrine glands
- produces growth hormone
B. Thyroid gland
- produces thyroxine
- regulates metabolism
- needs iodine for proper functioning
C. Pancreas
- produces:
- insulin
- glucagon
- controls blood sugar level
D. Adrenal glands
- produce adrenaline
- helps body respond to stress, fear, or emergency
E. Testes
- produce testosterone
- responsible for male secondary sexual characters
F. Ovaries
- produce estrogen and progesterone
- responsible for female secondary sexual characters and reproductive cycle
8) Feedback mechanism
Hormone levels in body are controlled by a feedback mechanism.
Example:
If blood sugar increases, pancreas releases insulin to bring it back to normal.
If blood sugar decreases, glucagon raises it.
This keeps the body in balance.
9) Coordination in plants
Plants do not have a nervous system like animals, but they still respond to stimuli.
Plant responses happen through:
- growth movements
- chemical coordination using hormones
10) Plant hormones
Important plant hormones are:
- Auxin
- Gibberellin
- Cytokinin
- Abscisic acid (ABA)
A. Auxin
- helps in cell elongation
- responsible for phototropism
- found at the growing tip of plants
B. Gibberellin
- stimulates stem elongation
- helps in seed germination
C. Cytokinin
- promotes cell division
- delays aging of leaves
D. Abscisic acid (ABA)
- inhibits growth
- helps in closing stomata
- causes dormancy in seeds
11) Movement in plants
Plants show two main types of movements:
A. Tropic movements
Directional growth movements in response to stimulus.
Types:
- Phototropism: response to light
- Geotropism / gravitropism: response to gravity
- Hydrotropism: response to water
- Thigmotropism: response to touch
- Chemotropism: response to chemicals
B. Nastic movements
Non-directional movements in response to stimulus.
Example:
- folding of leaves in Mimosa pudica on touch
12) Phototropism
When a plant bends towards light, it shows positive phototropism.
Why does this happen?
Auxin accumulates on the shaded side, causing more cell elongation there. So the plant bends toward light.
13) Hormonal control in animals: adrenal and pancreas
Adrenaline
Released during:
- fear
- anger
- stress
- excitement
It causes:
- increased heart rate
- faster breathing
- more glucose in blood
- better blood flow to muscles
Insulin
- lowers blood glucose level
- helps cells absorb glucose
- lack of insulin causes diabetes
14) Important differences
Nervous system vs endocrine system
| Nervous system | Endocrine system |
|---|---|
| Uses electrical impulses | Uses hormones |
| Fast response | Slow response |
| Short-lasting effect | Long-lasting effect |
| Travels through nerves | Travels through blood |
15) Very important exam points
- Neuron is the basic unit of nervous system.
- Reflex action is controlled by spinal cord.
- Brain is the control center of the body.
- Pituitary gland is the master gland.
- Thyroxine controls metabolism.
- Insulin controls blood sugar.
- Auxin helps in phototropism.
- Plant hormones control growth and responses.
16) Short revision notes
- Control = managing body activities
- Coordination = working together of organs
- Nervous system = fast response
- Hormonal system = slow but long-lasting response
- Plants respond through hormones and growth movements
- Animals use both nervous and endocrine systems
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- short exam notes,
- important questions and answers, or
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Send fully detailed
Below are fully detailed Class 10 Science notes for Chapter: Control and Coordination.
Control and Coordination
Living organisms need to detect changes in their surroundings and respond appropriately. This ability is called sensitivity or responsiveness. The process by which an organism regulates and integrates its activities is called control and coordination.
In animals, coordination is mainly done by the nervous system and endocrine system. In plants, coordination happens through chemical substances called hormones and growth movements.
1. Need for Control and Coordination
Organisms live in changing environments. They need control and coordination to:
- survive in different conditions
- respond to light, temperature, touch, danger, food, and water
- maintain internal balance
- carry out activities in an organized way
Without control and coordination, body parts would work independently and the organism could not survive properly.
2. Control and Coordination in Animals
Animals have a highly developed system of coordination because they move actively and react quickly to stimuli.
There are two main systems:
- Nervous system
- Endocrine system
3. Nervous System
The nervous system controls and coordinates body activities by sending electrical impulses.
Main functions
- receives information from the environment
- processes the information
- sends commands to muscles and glands
- controls voluntary and involuntary actions
- helps in reflex actions
4. Neuron: Basic Unit of Nervous System
A neuron is the structural and functional unit of the nervous system.
Parts of a neuron
a) Cell body
- contains nucleus and cytoplasm
- controls the activities of the neuron
b) Dendrites
- short branched structures
- receive signals from receptors or other neurons
c) Axon
- long fiber
- carries nerve impulse away from the cell body
d) Axon terminals / nerve endings
- pass signal to another neuron, muscle, or gland
e) Myelin sheath
- fatty covering around axon in many neurons
- increases speed of impulse transmission
- formed by Schwann cells
f) Node of Ranvier
- gaps in myelin sheath
- help in faster conduction of impulses
5. How Nerve Impulses Travel
The transmission of information in the form of electrical signals is called a nerve impulse.
Steps:
- A stimulus acts on a receptor.
- Receptor converts stimulus into nerve impulse.
- Impulse travels through sensory neuron.
- It reaches the spinal cord or brain.
- Brain/spinal cord processes the information.
- Command is sent through motor neuron.
- Effector organ responds.
6. Synapse
A synapse is a small gap between two neurons or between a neuron and an effector organ.
How impulses cross a synapse
- electrical impulse reaches axon terminal
- neurotransmitter chemicals are released
- chemicals cross the synaptic gap
- next neuron receives the signal
Importance
- allows orderly transfer of information
- ensures one-way flow of impulses
7. Types of Nervous System in Humans
The human nervous system has three main parts:
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
- Autonomous Nervous System (ANS)
A. Central Nervous System
The CNS consists of:
- brain
- spinal cord
It is the main control center of the body.
B. Peripheral Nervous System
The PNS consists of all nerves arising from the brain and spinal cord.
It connects the CNS to:
- sense organs
- muscles
- glands
- other body parts
C. Autonomous Nervous System
The ANS controls involuntary actions such as:
- heartbeat
- breathing
- digestion
- sweating
- pupil movement
It works without our conscious control.
8. Reflex Action
A reflex action is a quick, automatic, and involuntary response to a stimulus.
Examples
- withdrawing hand from a hot object
- blinking of eyes
- sneezing
- coughing
- knee jerk
Importance
- protects the body from injury
- gives rapid response
- does not require thinking
9. Reflex Arc
The pathway taken by nerve impulses in a reflex action is called a reflex arc.
Path of reflex arc
Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector → Response
Example
When you touch a hot pan:
- receptors in skin detect heat
- sensory neuron sends signal to spinal cord
- spinal cord immediately sends message through motor neuron
- muscles contract
- hand is pulled away
Why spinal cord?
Reflex actions are controlled by the spinal cord because it is faster than sending the message to the brain first.
10. Human Brain
The brain is the main control organ of the body. It is located in the skull and protected by:
- cranium
- meninges
- cerebrospinal fluid
Functions of brain
- thinking
- memory
- learning
- intelligence
- emotions
- voluntary movement
- regulation of body activities
Major parts of the brain
A. Forebrain
The largest part of the brain.
Includes:
- cerebrum
- thalamus
- hypothalamus
Functions:
- controls voluntary actions
- receives sensory information
- responsible for intelligence, memory, reasoning, and emotions
- helps in hunger, thirst, body temperature regulation
B. Midbrain
- connects forebrain and hindbrain
- controls visual and auditory reflexes
C. Hindbrain
Includes:
- cerebellum
- pons
- medulla oblongata
Functions:
- Cerebellum: balance, posture, and muscle coordination
- Pons: connects different parts of brain; helps in breathing
- Medulla oblongata: controls involuntary functions like heartbeat, breathing, blood pressure, swallowing
11. Voluntary and Involuntary Actions
Voluntary actions
Actions that are under conscious control.
Examples:
- writing
- walking
- speaking
- reading
These are controlled mainly by the cerebrum.
Involuntary actions
Actions that are not under conscious control.
Examples:
- heartbeat
- breathing
- digestion
These are controlled by the medulla oblongata and autonomic nervous system.
12. Endocrine System
The endocrine system consists of glands that release hormones directly into the blood.
Hormones
Hormones are chemical messengers that regulate body functions.
Features of hormones
- secreted in small amounts
- transported through blood
- act on specific target organs
- slower than nervous system
- effects are long-lasting
13. Important Endocrine Glands and Hormones
A. Pituitary gland
- located at the base of the brain
- called the master gland
- controls other endocrine glands
- secretes growth hormone
Growth hormone
- regulates growth of bones and body
- lack of it causes stunted growth
- excess may cause abnormal growth
B. Thyroid gland
- located in the neck
- secretes thyroxine
Thyroxine
- regulates metabolism
- needs iodine for its production
Iodine deficiency
causes enlargement of thyroid gland called goitre
C. Pancreas
- mixed gland: acts as endocrine and exocrine gland
- produces insulin and glucagon
Insulin
- lowers blood sugar level
- helps cells take in glucose
Glucagon
- raises blood sugar level
Diabetes
- condition caused by lack of insulin or poor insulin action
- blood sugar level remains high
D. Adrenal glands
- located above kidneys
- secrete adrenaline
Adrenaline
- called the emergency hormone
- released in stress, fear, excitement, or danger
Effects of adrenaline
- increases heart rate
- increases breathing rate
- increases blood pressure
- raises blood glucose
- prepares body for fight-or-flight response
E. Testes
- male reproductive glands
- se
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