Schooling · Class 10 · Science · Control and Coordination · Chapter on a page
CBSE Class 10 · Science · NCERT Science
Control and Coordination: chapter on a page
A cut of Shishya's notes for this chapter: the first paragraph of the introduction and the key ideas, formulas and facts, common mistakes and quick revision lists, word for word. Nothing is added or reworded; the worked examples are left out (they are on the chapter page).
About the notes: Written by Shishya's AI on 26 Sept 2026 from the chapter's title and class level, in Shishya's own words — not a copy or summary of the textbook. Read the official chapter for the book's own text, activities and exercises.
This note's current text has no applied fact-check on record.
Mind map
Drawn from the same notes by a fixed rule (no AI): each label is the item's own words — its bold term, its label before a colon, a short formula as written, or its first words.
The mind map as a list
- Key ideas
- Stimulus and response
- Neurons are the functional units of…
- Reflex arc provides quick, automatic…
- The brain has three main regions
- Hormones are chemical messengers…
- Plants show tropic movements in…
- Plant hormones like auxin control…
- Formulas and facts
- Neuron structure
- Reflex arc pathway
- Synapse
- Parts of the brain
- Major endocrine glands and hormones
- Insulin regulates blood glucose
- Iodine is needed to make thyroxine
- Worked examples
- Identifying parts of a reflex arc
- Hormone deficiency problem
- Plant tropism
- Watch out for
- Thinking reflex actions involve the…
- Confusing nerves and neurons
- Believing hormones act instantly…
- Assuming all plant movements are…
- Mixing up insulin and glucagon
What this chapter is about
This chapter explains how living organisms detect changes in their environment and respond to them in a controlled manner. It covers two main systems that help animals coordinate their body functions: the nervous system and the endocrine system. Plants also show responses to stimuli, though they lack a nervous system.
Key ideas
- Stimulus and response: A stimulus is any change in the environment that an organism detects; a response is the action taken by the organism in reaction to that stimulus.
- Neurons are the functional units of the nervous system: Each neuron has a cell body, dendrites that receive information, and an axon that carries impulses away to other neurons or muscles.
- Reflex arc provides quick, automatic responses: In a reflex action, the impulse travels from receptor to sensory neuron, then to relay neuron in the spinal cord, then to motor neuron, and finally to effector organ, bypassing the brain for speed.
- The brain has three main regions: The forebrain (cerebrum) handles thinking, memory and voluntary actions; the midbrain controls some reflexes; the hindbrain (cerebellum and medulla) manages balance, posture and involuntary functions like breathing.
- Hormones are chemical messengers secreted by endocrine glands: They travel through blood and act on specific target organs to regulate growth, metabolism, reproduction and other processes.
- Plants show tropic movements in response to stimuli: Phototropism is growth towards or away from light; geotropism is response to gravity; hydrotropism is response to water.
- Plant hormones like auxin control growth: Auxin accumulates on the shaded side of a stem, causing cells there to elongate more, so the plant bends towards light.
Formulas and facts to remember
- Neuron structure: Dendrite → Cell body → Axon → Axon terminal (synapse).
- Reflex arc pathway: Receptor → Sensory neuron → Relay neuron (in spinal cord) → Motor neuron → Effector.
- Synapse: The small gap between two neurons where chemical signals (neurotransmitters) pass the impulse from one neuron to the next.
- Parts of the brain: Cerebrum (thinking, memory), Cerebellum (balance, coordination), Medulla oblongata (breathing, heartbeat).
- Major endocrine glands and hormones: Pituitary (growth hormone), Thyroid (thyroxine for metabolism), Pancreas (insulin for blood sugar), Adrenal (adrenaline for emergency response), Testes (testosterone), Ovaries (oestrogen).
- Insulin regulates blood glucose: It lowers blood sugar by helping cells absorb glucose; its deficiency causes diabetes.
- Iodine is needed to make thyroxine: Deficiency of iodine causes goitre, an enlargement of the thyroid gland.
- Auxin, gibberellin and cytokinin are plant hormones: Auxin promotes cell elongation; gibberellin promotes stem growth; cytokinin promotes cell division.
Common mistakes
- Thinking reflex actions involve the brain → Reflex arcs pass through the spinal cord, not the brain, which is why they are fast and involuntary.
- Confusing nerves and neurons → A neuron is a single nerve cell; a nerve is a bundle of many neuron fibres wrapped together.
- Believing hormones act instantly like nerve impulses → Hormones travel through blood and take longer to act, but their effects last longer than nerve impulses.
- Assuming all plant movements are tropisms → Tropisms involve growth; nastic movements (like leaf folding in touch-me-not) are non-directional and do not depend on stimulus direction.
- Mixing up insulin and glucagon → Insulin lowers blood sugar; glucagon (also from pancreas) raises it. Diabetes results from insulin problems.
Quick revision
- Nervous system uses electrical impulses; endocrine system uses chemical hormones carried by blood.
- Reflex arc: Receptor → Sensory neuron → Relay neuron → Motor neuron → Effector.
- Cerebrum thinks, cerebellum balances, medulla controls involuntary actions.
- Insulin from pancreas controls blood sugar; thyroxine from thyroid controls metabolism.
- Auxin causes phototropism by making the shaded side of stems grow faster.
- Iodine deficiency causes goitre; growth hormone deficiency causes dwarfism.