control and coordination notes class 10 cbse board short easy notes

 

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Class 10 – Control and Coordination Notes

1. What is Control and Coordination?

Control and coordination is the process by which different parts of the body communicate and work together to maintain proper functioning.

• Control – Ability to regulate body functions

• Coordination – Ability to coordinate between different organs and systems

Main systems involved:

1. Nervous system – rapid responses using electrical signals

2. Endocrine system (hormones) – slower responses using chemical signals

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2. Nervous System

Definition: A system that receives stimuli, processes information, and sends responses using nerves.

Parts of the Nervous System:

1. Central Nervous System (CNS):

   • Brain – controls thinking, memory, emotions

   • Spinal cord – reflex actions, connects brain to body

2. Peripheral Nervous System (PNS):

   • Nerves connecting CNS to organs

   • Two types:

     • Sensory nerves → carry messages from sense organs to CNS

     • Motor nerves → carry messages from CNS to muscles/glands

Neurons (Nerve Cells):

• Functional unit of the nervous system

• Structure:

  1. Cell body – nucleus and cytoplasm

  2. Dendrites – receive signals

  3. Axon – sends signals to other neurons/muscles

• Signals are electrical impulses.

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3. Reflex Action

Definition: An automatic, rapid response to a stimulus without conscious control.

Example:

• Touching a hot object → hand withdraws immediately

• Knee-jerk reflex

Pathway (Reflex Arc):
Stimulus → Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector → Response

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4. Coordination in Plants

• Plants lack a nervous system, but coordinate using hormones (chemical messengers) called phytohormones.

Major Plant Hormones:

Hormone	Function	Example
Auxin	Promotes growth of stem towards light	Phototropism
Gibberellin	Stimulates stem elongation	Stem growth
Cytokinin	Promotes cell division	Leaf development
Ethylene	Ripening of fruits	Banana ripening
Abscisic Acid (ABA)	Inhibits growth, closes stomata	Seed dormancy

Tropism:

• Movement or growth in response to stimuli

  • Phototropism → towards light

  • Geotropism → response to gravity

  • Hydrotropism → towards water

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5. Endocrine System (Hormonal Coordination in Humans)

Definition: Hormones are chemical messengers secreted by glands to regulate body processes.

Major Endocrine Glands and Functions:

Gland	Hormone	Function
Pituitary	Growth hormone	Growth, development
Thyroid	Thyroxine	Metabolism, growth
Adrenal	Adrenaline	Fight or flight response
Pancreas	Insulin	Lowers blood sugar
Ovaries	Estrogen	Female reproductive system
Testes	Testosterone	Male reproductive system

Key point:

• Nervous system → fast response

• Endocrine system → slow but long-lasting effect

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Quick Summary Table

Aspect	Nervous System	Endocrine System
Signal Type	Electrical	Chemical
Speed	Fast	Slow
Duration	Short	Long
Examples	Reflex action	Growth, metabolism

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Tips for Blog Posting

1. Use headings for each section (<h2> for main, <h3> for subtopics)

2. Use tables and bullet points → more readable

3. Include diagrams:

   • Reflex arc

   • Plant tropism

   • Human endocrine glands