These notes for CBSE Class 10 Science, Chapter 7, focus on Control and Co-ordination. They explain coordination as the synchronized working of body organs in response to stimuli. The chapter details how control and coordination occur in animals through the nervous and endocrine systems. The nervous system's structure, including neurons, synapses, and reflex arcs, is described, along with the central and peripheral nervous systems and the parts of the brain (forebrain, midbrain, hindbrain) and their functions. The endocrine system's role through hormones is also covered, highlighting key endocrine glands like the pituitary, thyroid, pancreas, testes, and ovaries, and the hormones they secrete. Additionally, the notes discuss coordination in plants, explaining tropic and nastic movements, and introducing plant hormones like auxins, gibberellins, cytokinins, and abscisic acid. These notes are designed to aid students in revising the key concepts for their exams.
Last optimized 10 Aug 2026
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? Coordination-The working together of various organs of the body of an organism in a proper manner to produce appropriate reaction to a stimulus is called coordination.
? Stimulus- The changes in the environment to which an organism responds and reacts is called
Stimulus
? Control & coordination in animals- takes place by
(i) Nervous system & (ii) Endocrine system
? Nervous system
Stimulus ? Receptor organ ? Sensory nerve ? Brain/Spinal cord
? Response ? Effector organ ? Motor nerve
? Endocrine system
Stimulus ? Endocrine organ ? Secrete hormone ? Hormone in blood ? Response ? Target organ
? Parts of the Nervous system –
(i) Brain (ii) Spinal cord (iii) Nerves (Neurons)
? A Neuron is the structural & functional unit of Nervous system
? Parts of a neuron-
(i) Dendrites (ii) Cell body (iii) Axon
? Synapse- Space/junction between two adjacent nerves is called Synapse.
? Passing of information takes place –
(i) By Electric impulse (inside the neuron) and
(ii) In the form of chemicals (At synapse)
? Reflex action- Spontaneous, involuntary and automatic response to a stimulus to protect us from harmful situations. Eg. On touching a hot object unknowingly we instantly withdraw our hand.
? Reflex arc- The pathway of the reflex action is called Reflex arc.
Stimulus ? Receptor organ ? Sensory nerve ? Spinal cord ?Effector organ? Response
Refer to figure 7.2 page no. 117 of N.C.E.R.T Text book)
? Nervous system-
(1) Central Nervous system (CNS)
(2) Peripheral Nervous system(PNS)
(i) Brain (i) Autonomic Nervous system
(ii) Spinal cord (ii) Voluntary Nervous system
? Brain
(i) Centre of coordination of all activities
(ii) Thinking is involved
(iii) Complex process
? Parts of brain-
Refer to figure 7.3 page no. 118 of N.C.E.R.T Text book
Fore brain |
Mid brain |
Hind brain |
(i) Cerebrum (ii) Thalamus (iii) Hypothallamus |
---------- |
(i) Cerebellum (ii) Pons (iii) Medulla oblongata |
? Fore brain
Cerebrum-
(i) Main thinking and largest part of the brain.
(ii) It has 3 main areas-
a) Sensory area- to receive impulses from sense organs via Receptors b ) Motor area- control voluntary movements.
c) Association areas- Reasoning, learning & intelligence. Thalamus – It relays sensory information to the Cerebrum
Hypothallamus- It forms the link between Nervous system & Endocrine system
? Mid brain- It connects Fore brain and Hind brain. Controls reflex of eyes & ears
? Hind brain- Connects the Fore brain & Hind brain
Cerebellum – Controls & coordinates muscular movements, maintaining body posture and equilibrium.
Pons- Acts as a bridge between brain & spinal cord
Medulla oblongata- Controls involuntary actions like blood pressure, salivation, vomiting, etc.
? Spinal cord- Cylindrical or tubular structure extending downwards from the Medulla oblongata.
? Protection of the brain & the spinal cord-
(i) Bony outer covering: skull for the brain & vertebral column for the spinal cord.
(ii) Cerebrospinal fluid present in between the three membranes.
? Action caused by Nervous tissue
Information ? Nervous tissue ? Brain Muscles ? Causes action
? Path or action-
Nerve impulse ? Muscle cell ? Changes shape due to special proteins ? Action caused ? Shorter form of muscles ? Change shape & arrangement of cell
? Chemical communication by hormones- (advantages)
(i) Electrical impulses have their limitations because they reach only those cells connected to the nervous tissue.
(ii) Also the nerve cells cannot generate & transmit impulses continuously.
iii)Electrical communication is slower. ? Hormones-
(i) are chemical messengers secreted by endocrine glands
(ii) Are secreted in small amounts & may act in nearby places or distant places.
(iii) Do not take part in the reaction & are destroyed immediately.
? Hormones are secreted by- Endocrine glands & Exocrine glands
S. No. |
Endocrine glands |
Exocrine glands |
1. |
Ducts absent |
Ducts present |
2. |
Secrete hormones |
Secrete enzymes |
3. |
Secreted in blood |
Secreted in ducts of glands |
4. |
Situated away from the site of action |
Situated near the site of action |
? Some glands which act as both endocrine & exocrine
Gland |
Endocrine function |
Exocrine function |
Pancreas |
Produces insulin & Glucagon hormone. |
Produces digestive enzyme. (pancreatic amylase) |
Testes |
Produces hormone Testosterone |
Produces male gametes (reproductive cells) |
Ovaries |
Produces hormone Oestrogen |
Produces female gametes (reproductive cells) |
? Important Endocrine glands, the hormone they secrete & their function Refer to figure 7.7 page no. 124 of N.C.E.R.T Text book)
Endocrine gland |
Hormone |
Function |
Pituitary gland |
Growth hormone |
Body growth, development of bones & muscles (If excess- Gigantism) (If less- Dwarfism) |
Thyroid gland |
Thyroxine |
Regulates carbohydrate, protein & fat metabolism |
Pancreas |
Produces insulin & Glucagon hormone |
Regulates blood sugar levels (if less diabetes is caused) |
Testes in males |
Produces hormone Testosterone |
Development of secondary male characters like deep voice, beard, etc. |
Ovaries in females |
Produces hormone Oestrogen |
Development of secondary female characters like mammary glands, menstrual cycle, maintenance of pregnancy. |
? Coordination in plants- Only chemical coordination is present in plants.
? Tropic movements- The movements of plants in the direction of stimulus (positive) or away from it (negative) are called tropic movements. E.g. Phototropism, Geotropism. Chemotropism.
Refer to figure 7.4 & 7.5 page no. 121 of N.C.E.R.T Text book)
? Nastic movements -The movements of plants independent of stimuli are called nastic movements. E.g.- Touch me not plant leaves close when touched.
? Plant hormones (Phytohormones) Examples-
1. Auxins- Help in growth of root & shoot tips.
2. Gibberellins- Help in vegetative growth
3. Cytokinins- Promote cell division
4. Abscissic acid - Inhibits growth & causes wilting (falling) of leaves
? Important diagrams-
1. Structure of neuron (nerve cell)
2.Reflex arc
3.Human brain
4.Endocrine glands .
Coordination is the process where different organs of an organism work together efficiently to produce an appropriate response to a stimulus.
Animals achieve control and coordination through two main systems: the nervous system and the endocrine system.
A neuron is the structural and functional unit of the nervous system. Its main parts are dendrites, the cell body, and the axon.
A reflex action is a rapid, involuntary, and automatic response to a stimulus, designed to protect the body from harm, like quickly withdrawing a hand from a hot object.
Hormones are chemical messengers secreted by endocrine glands that travel through the bloodstream to target organs, regulating various bodily functions.
Plants coordinate their activities primarily through chemical coordination using plant hormones (phytohormones) and exhibit tropic and nastic movements in response to stimuli.
Tropic movements are directional growth movements of plants in response to a stimulus, such as phototropism (towards light) or geotropism (towards gravity).
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