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CONTROL AND COORDINATION โ The process by
which all activities of the body are regulated and coordinated to maintain homeostasis. โ Control: Ability to monitor and regulate body activities โ Coordination: Ability of different organs and systems to work together efficiently
IMPORTANCE:
โ Enables response to external stimuli โ Helps in adaptation and survival โ Ensures proper functioning of organs and organ systems
โก Important for CBSE Exams :
โ Control and coordination are essential for survival and adaptation.
๐ก Trick to Remember:
โ โControl = Brain; Coordination = Bodyโ โ links control with CNS and coordination with muscles/organs
2 ๐ก NERVOUS SYSTEM
The nervous system is the main control and coordination system, allowing the body to sense, process, and respond quickly.
COMPONENTS:
- Central Nervous System (CNS)
Interesting fact!
Your brain has 100 billions neurons sending trillions of messages every second
โ Brain + Spinal Cord โ Function: Processes information and coordinates responses
- Peripheral Nervous System (PNS) โ All nerves outside CNS โ Function: Connects CNS to organs, muscles, and sense organs โ
PROTECTION OF CENTRAL
NERVOUS SYSTEM (CNS)
The CNS (Brain and Spinal Cord) is very delicate and is protected by following
- Bony Structures: โ Brain: Protected by the skull (cranium) โ Spinal Cord: Protected by the vertebral column
- Membranes (Meninges): โ Three protective layers surrounding brain and spinal cord: 1. Dura Mater โ outer tough layer 2. Arachnoid Mater โ middle web-like layer 3. Pia Mater โ inner delicate layer, closely attached to CNS
- Cerebrospinal Fluid (CSF): โ Cushions the brain and spinal cord โ Protects from shock or injury
TYPES OF NERVES (CBSE FOCUS)
Dendrites Receive impulses from other neurons or sense organs Axon Transmits impulses away from the cell body Myelin Sheath Fatty covering, speeds up impulse conduction Nodes of Ranvier Gaps in myelin sheath, help rapid conduction Axon Terminals Transmit impulses to next neuron or effector organ
TYPES OF NEURONS (CBSE FOCUS)
โ Sensory Neuron: Sense organs โ CNS โ Motor Neuron: CNS โ Muscles/Glands โ Relay Neuron: Connects sensory and motor neurons within CNS
โก Important for CBSE Exams :
โ Dendrites receive impulses, Axon sends impulses โ Myelin sheath โ speeds up transmission
Mini Self-Test:
- Name the neuron that connects sensory and motor neurons. 2 What is the function of dendrites?
๐ก Quick Trick:
โ โSMD โ Send, Move, Decideโ โ Sensory (Send), Motor (Move), Relay (Decide/Connect)
4 ๐ก SENSE ORGANS AND
RECEPTORS
โ The body responds to stimuli through specialized sensory receptors present in sense organs. These receptors detect specific types of stimuli and send signals to the CNS. โ Receptor Stimulus Detected Associated Organ Photoreceptor Light Eye Olfactory Receptor Smell Nose Gustatory Receptor Taste Tongue Phonothermal Receptor Sound & Temperature Ear & Skin
โ The brain may not be involved initially; the spinal cord handles the response Difference Between Actions: โ Type of Action Control Speed of Response Example Voluntary Action Conscious control Relatively slow Writing, walking, speaking Involuntary Action Not under conscious control Slow or moderate Heartbeat, digestion, secretion of glands Reflex Action Not under conscious control Very fast Pulling hand from hot object, blinking Important for CBSE Exams: โ Reflex actions are involuntary and fastest โ Voluntary actions involve thinking and decision-making
โ Involuntary actions maintain homeostasis
Mini Self-Test:
- Which part of the nervous system mediates most reflex actions?
- Name the neuron that connects sensory and motor neurons in a reflex arc. 3 Which action is the fastest: voluntary, involuntary, or reflex?
6 ๐ก BRAIN AND SPINAL CORD (CNS)
- The Central Nervous System comprises the brain and spinal cord, responsible for processing information and coordinating responses.
4. Brain:
Part Function Cerebrum Thinking, memory, learning, voluntary actions Cerebellum Coordination of muscles, posture, balance Medulla Oblongata Involuntary actions like breathing, heartbeat Hypothalamus Maintains homeostasis, controls hunger, thirst, body temperature
SPINAL CORD
โ Extends from the brain down the vertebral column โ Function: Transmits impulses between brain and body โ Controls spinal reflexes independently
7 ๐ก COORDINATION IN HUMANS
Coordination โ The harmonious functioning of different organs and systems in response to internal or external stimuli.
HOW COORDINATION OCCURS:
- Nervous System โ Rapid responses via electrical impulses
- Hormonal (Endocrine) System โ Slower responses via chemical messengers (hormones) Example: โ Nervous system: Pulling hand from hot stove (fast) โ Hormonal system: Regulating blood sugar via insulin (slower)
ENDOCRINE SYSTEM
The endocrine system is the chemical coordination system of the body. It uses hormones secreted by glands to regulate body functions, including growth, metabolism, reproduction, and homeostasis. โ Hormones: Chemical messengers that travel in the blood to target organs. โ Difference from nervous system: Slower response but long-lasting effects.
โ MAJOR ENDOCRINE GLANDS,
HORMONES & FUNCTIONS
Gland Location Hormone(s) Secreted Function Pituitary Gland Base of brain Growth hormone (GH), Thyroid- stimulating hormone (TSH), FSH, LH Controls growth, stimulates thyroid, reproductive organs, regulates other glands Thyroid Neck, below Adamโs apple Thyroxine Regulates metabolism, growth, and development Parathyroid On thyroid gland Parathormone (PTH) Maintains calcium and phosphate balance Adrenal Glands On top of kidneys Adrenaline, Cortisol Adrenaline: Fight or flight response; Cortisol: Stress management, metabolism Pancreas Abdomen, behind Insulin, Glucagon Insulin: lowers blood
โP.T. P.A.P.A.โ โ Pituitary, Thyroid, Parathyroid, Adrenal, Pancreas, And reproductive organs (Ovaries/Testes)
FEEDBACK MECHANISM
Definition: A process by which the level of a substance or hormone in the body is monitored and regulated to maintain balance (homeostasis). Example: โ Blood sugar regulation: โ High blood sugar โ detected by cells in pancreas โ insulin released โ sugar level decreases โ balance maintained
โก Important for CBSE Exams :
โ Feedback mechanism ensures homeostasis
COORDINATION IN PLANTS
Coordination in Plants โ The process by which plants regulate their growth, development, and responses to stimuli using plant hormones. โ Unlike animals, plants do not have a nervous system. โ Coordination occurs chemically through hormones and physically through tropic/nastic movements.
1 ๐ก PLANT HORMONES
(PHYTOHORMONES)
Hormone Organ/Location Function Auxins Tips of shoots and roots Promote cell elongation, growth towards light (phototropism)
Gibberellins Young leaves, roots, seeds Promote stem elongation, seed germination Cytokinins Roots, shoots Stimulate cell division and delay aging Abscisic Acid (ABA) Leaves, fruits Inhibits growth, closes stomata during drought, promotes dormancy Ethylene Ripening fruits Promotes fruit ripening and leaf abscission
2 ๐ก TYPES OF MOVEMENTS IN
PLANTS
Movement Type Direction Mechanism Example Tropic Movement Directional (towards/away from stimulus) Caused by differential growth Phototropism (shoots grow towards light), Geotropism (roots grow down) Nastic Movement Non-directional Caused by turgor changes Closing of Mimosa pudica leaves
Important for CBSE Exams :
- Which system coordinates fast responses in animals?
- Name a plant hormone that promotes seed germination.
PYQโS
1 How does blood sugar level get regulated in the human
body?
โ High blood sugar โ pancreas detects โ insulin released โ glucose converted to glycogen โ blood sugar decreases. โ Low blood sugar โ pancreas detects โ glucagon released โ glycogen converted to glucose โ blood sugar increases. Keywords: pancreas, insulin, glucagon, glycogen, blood sugar regulation
2 Where are auxins synthesized? How do they promote
phototropism?
โ Synthesized in: tips of shoots and young leaves โ Promote phototropism: Auxins accumulate on shaded side, elongate cells, causing shoot to bend towards light. Keywords: auxins, shoot tip, cell elongation, phototropism, shaded side
3 A doctor has advised Sameer to reduce sugar intake in
his diet and do regular exercise after checking his blood
test reports. Which disease do you think Sameer is
suffering from? Name the hormone responsible for this
disease and the organ producing the hormone.
โ Disease: Diabetes mellitus โ Hormone: Insulin โ Organ: Pancreas
Keywords: diabetes mellitus, insulin, pancreas, sugar regulation
4 Which hormone is present in the areas of rapid cell
division in a plant? How does it help the plant to cope
up in an emergency situation?
โ Hormone: Cytokinin โ Function: Stimulates cell division, promotes growth and repair, helps plant cope with damage or stress. Keywords: cytokinin, cell division, growth, stress response
5 How is the timing and the amount of release of insulin in
the blood regulated?
โ Regulated by: feedback mechanism โ Mechanism:
โ High blood sugar โ pancreas releases insulin โ sugar level
decreases โ insulin release slows down Keywords: insulin, pancreas, feedback mechanism, blood sugar regulation
Tips & Tricks โ Control and
Coordination
- Highlight keywords โ Hormones, Glands, Processes.
- Use small diagrams โ Reflex arc, Neuron, Brain, Plant movements.
- Write point-wise answers โ Short, precise, and clear.
- Link hormone โ gland โ function โ Easy marks in exams.
โ Examples: Phototropism, Geotropism, Hydrotropism, Thigmotropism, Mimosa leaf movement
5 PYQs & High-Yield Questions
โ Blood sugar regulation (Insulin/Glucagon) โ Auxin and phototropism โ Diabetes mellitus โ hormone & gland โ Cytokinin โ cell division and stress response โ Feedback mechanism questions
โก EXAM TIP:
โ Questions from neurons, reflex arc, brain, endocrine glands, plant hormones, and tropic movements are very frequently repeated in CBSE Class 10 exams. โ Focus on tables, diagrams, and one-line functions โ easy marks.
