Control and Coordination

Organisms ko apne environment mein changes ke according respond karna zaroori hota hai. Iss process ko control aur coordination kehte hain.

• Control: Body ke different parts ko regulate karna.
• Coordination: Body ke different parts ke functions ko synchronize karna taki ek effective response generate ho sake.
• Stimulus: Koi bhi change environment mein jisko organism detect karta hai aur respond karta hai (e.g., light, heat, touch, sound, chemical).
• Response: Stimulus ke against organism ka reaction (e.g., move karna, grow karna).

Animals mein nervous aur muscular tissues control aur coordination provide karte hain. Plants mein nervous system ya muscles nahi hote, toh woh hormones ke through coordinate karte hain.

Animals mein, especially humans mein, control aur coordination ke liye nervous system aur endocrine system dono hote hain.

Nervous System ke Components:

• Neurons (Nerve Cells): Nervous system ki structural aur functional unit. Ye information ko electrical impulses ke form mein transmit karte hain.
• Receptors: Specialized nerve endings jo stimuli ko detect karte hain. Ye sense organs mein hote hain.
• Gustatory receptors: Taste detect karte hain (tongue).
• Olfactory receptors: Smell detect karte hain (nose).
• Photoreceptors: Light detect karte hain (eyes).
• Phonoreceptors: Sound detect karte hain (inner ear).
• Thermoreceptors: Heat/cold detect karte hain (skin).
• Mechanoreceptors: Touch/pressure detect karte hain (skin).
• Effectors: Muscles ya glands jo response generate karte hain.

Neuron ka Structure:

[IMAGE: TODO: Structure of neuron]

• Dendrite: Tree-like branches jo information receive karte hain receptors se ya dusre neurons se.
• Cell Body (Cyton/Soma): Dendrites se aayi information ko process karta hai aur nucleus contain karta hai.
• Axon: Longest part jo electrical impulse ko cell body se away transmit karta hai, nerve ending tak.
• Nerve Ending: Axon ka terminal part jahan electrical impulse chemical signals mein convert hota hai.

Nerve Impulse ka Transmission:

1. Stimulus reception: Dendrite tip par stimulus detect hota hai.
2. Chemical reaction: Stimulus ek chemical reaction trigger karta hai jo electrical impulse (nerve impulse) banata hai.
3. Impulse travel: Impulse dendrite \(\rightarrow\) cell body \(\rightarrow\) axon \(\rightarrow\) nerve ending tak travel karta hai.
4. Synapse par transmission: Nerve ending par, electrical impulse chemicals release karta hai jinhe neurotransmitters kehte hain.
5. Synapse: Ye do neurons ke beech ka gap hota hai. Neurotransmitters is gap ko cross karte hain.
6. Next neuron mein impulse: Neurotransmitters next neuron ke dendrite par bind hote hain aur wahan ek naya electrical impulse generate karte hain.
7. Effector tak: Ye process tab tak chalta hai jab tak impulse effector (muscle ya gland) tak na pahunch jaaye.

Nervous tissue neurons ka ek organized network hai jo information ko electrical impulses ke through body ke ek part se dusre part tak conduct karta hai.

Reflex Action:

• Sudden, involuntary, aur automatic response to a stimulus.
• Ye bina conscious thought ke hota hai, matlab brain involve nahi hota decision-making mein.
• Example: Garam cheez ko touch karte hi haath hata lena, aankh ka jhapkaana (blinking), khana dekhte hi muh mein paani aana (salivation).
• Ye quick responses ke liye evolve hue hain taaki body ko harm se bachaya ja sake.

Reflex Arc:

• Reflex action ke दौरान nerve impulses jis pathway ko follow karte hain, usse reflex arc kehte hain.
• Ye spinal cord mein banta hai, brain tak information jaati hai but decision spinal cord hi le leta hai.

[IMAGE: TODO: Diagram of Reflex Arc]

Reflex Arc ke Components:

1. Receptor: Skin mein hota hai, jo stimulus (e.g., heat) ko detect karta hai.
2. Sensory Neuron (Afferent Neuron): Receptor se information ko spinal cord tak le jaata hai.
3. Relay Neuron (Interneuron): Spinal cord mein present hota hai, jo sensory neuron aur motor neuron ko connect karta hai.
4. Motor Neuron (Efferent Neuron): Spinal cord se information ko effector organ (muscle) tak le jaata hai.
5. Effector: Muscle ya gland jo response show karta hai (e.g., muscle contract karke haath hata lena).

• Importance: Reflex actions fast responses provide karte hain, jo dangerous situations mein body ko protect karte hain. Brain tak information pahunchne mein time lagta hai, isliye reflex arc spinal cord mein hi complete ho jaata hai.
• Difference from Voluntary Action: Voluntary actions mein brain conscious decision leta hai, jabki reflex actions mein brain ka conscious control nahi hota.

Brain body ka main coordinating centre hai. Ye spinal cord ke saath milkar Central Nervous System (CNS) banata hai. Brain skull ke andar protected hota hai.

[IMAGE: TODO: Diagram of Human Brain]

Human Brain ke Main Parts:

1. Forebrain (अग्रमस्तिष्क):

• Main thinking part of the brain.
• Cerebrum: Largest part of the brain. Iske different areas different functions ke liye specialized hote hain:
• Sensory areas: Receptors se sensory impulses receive karte hain (e.g., hearing, smell, sight).
• Association areas: Sensory information ko interpret karte hain, memory aur learning mein help karte hain.
• Motor areas: Voluntary muscles ke movement ko control karte hain (e.g., leg muscles).
• Hypothalamus: Body temperature, hunger, thirst, sleep, aur emotions ko regulate karta hai. Pituitary gland ko control karta hai.

2. Midbrain (मध्यमस्तिष्क):

• Forebrain aur hindbrain ko connect karta hai.
• Involuntary actions ko control karta hai, jaise pupil size mein changes aur head, neck, trunk ke reflex movements.

3. Hindbrain (पश्चमस्तिष्क):

• Cerebellum: Voluntary actions ki precision aur coordination ke liye responsible hai (e.g., walking in a straight line, riding a bicycle, picking up a pencil). Body ka posture aur balance maintain karta hai.
• Pons: Respiration ko regulate karta hai.
• Medulla Oblongata: Involuntary actions ko control karta hai, jaise blood pressure, salivation, vomiting, heartbeat, breathing.

Brain ke Functions ka Summary:

| Brain Part | Main Functions | | :------------ | :----------------------------------------------------------------------------------------------------------------- | | Forebrain | Thinking, memory, learning, reasoning, intelligence, voluntary actions, processing sensory information, hunger center. | | Midbrain | Involuntary actions (pupil size, reflex movements of head/neck/trunk). | | Hindbrain | Cerebellum: Posture, balance, precision of voluntary actions. | | | Pons: Respiration regulation. | | | Medulla: Involuntary actions (BP, heartbeat, breathing, vomiting, salivation). |

Brain ke different parts different inputs aur outputs ko integrate karte hain.

Brain aur spinal cord jaise delicate aur vital organs ko protection ki zaroorat hoti hai.

Brain ki Protection:

• Brain bony skull (cranium) ke andar protected hota hai.
• Skull ke andar, brain cerebrospinal fluid (CSF) se bhare balloon mein hota hai. Ye fluid shock absorption provide karta hai aur brain ko mechanical injuries se bachata hai.

Spinal Cord ki Protection:

• Spinal cord vertebral column (backbone) ke andar protected hoti hai.
• Vertebral column bony segments se bani hoti hai jo spinal cord ko support aur protection provide karti hai.

Nervous tissue information collect karta hai, process karta hai, decisions leta hai, aur phir muscles ko action ke liye instruct karta hai.

• Jab nerve impulse muscle tak pahunchta hai, toh muscle fibres ko move karna hota hai.
• Muscle cells movement ke liye apni shape change karte hain, jisse wo shorten ho jaate hain.
• Ye shape change muscle cells mein present special proteins ki wajah se hota hai.
• Ye proteins electrical impulses ke response mein apni shape aur arrangement change karte hain, jisse muscle contract hoti hai.
• Class IX mein padha tha ki muscles voluntary aur involuntary types ke hote hain. Nervous system in dono types ko control karta hai.
• Voluntary muscles: Brain ke conscious control mein hote hain (e.g., haath-pair hilana).
• Involuntary muscles: Brain ke conscious control mein nahi hote (e.g., heart beat, digestive system muscles).

Plants mein nervous system ya muscles nahi hote, phir bhi wo stimuli ko respond karte hain.

Growth-Independent Movements:

• Ye movements growth se related nahi hote aur kaafi fast ho sakte hain.
• Example: Mimosa pudica (Touch-me-not) plant ke leaves ka fold hona jab unhe touch kiya jaata hai.

Mechanism:

1. Stimulus detection: Touch detect hota hai.
2. Information transfer: Plants electrical-chemical means use karte hain information ko cell-to-cell communicate karne ke liye, lekin animals ki tarah specialized tissue nahi hota.
3. Cell shape change: Movement ke liye plant cells apni shape change karte hain. Ye water content change karke hota hai.

• Cells mein water ka loss hone se wo shrink ho jaate hain.
• Cells mein water ka gain hone se wo swell ho jaate hain.
• Mimosa pudica mein, touch karne par pulvini (base of petiole) ke cells se water loss hota hai, jisse leaves fold ho jaate hain.

Ye movements growth se related hote hain aur generally slow hote hain. Ye movements directional hote hain, ya toh stimulus ki taraf (positive tropism) ya usse door (negative tropism).

Types of Tropisms:

1. Phototropism (Light):

• Shoots: Light ki taraf bend karte hain (positive phototropism).
• Roots: Light se door grow karte hain (negative phototropism).
• Mechanism: Auxin hormone ismein major role play karta hai. Jab light ek side se aati hai, toh auxin shady side par diffuse ho jaata hai, wahan cells ko zyada grow karata hai, jisse shoot light ki taraf bend hota hai.

1. Geotropism (Gravity):

• Roots: Gravity ki taraf grow karte hain (positive geotropism).
• Shoots: Gravity se away grow karte hain (negative geotropism).

1. Hydrotropism (Water):

• Roots: Water ki taraf grow karte hain (positive hydrotropism).
• Example: Roots water source ki taraf grow karte hain.

1. Chemotropism (Chemicals):

• Growth in response to chemicals.
• Example: Pollen tube ka ovule ki taraf grow karna fertilization ke dauran.

1. Thigmotropism (Touch):

• Growth in response to touch.
• Example: Tendrils ka support ke around coil hona. Tendril ka jo part support ke contact mein aata hai, woh kam grow karta hai, aur dusra side zyada grow karta hai, jisse tendril coil ho jaati hai.

Plants mein chemical coordination plant hormones ya phytohormones ke through hota hai. Ye hormones growth, development, aur environment ke responses ko coordinate karte hain.

Major Plant Hormones:

1. Auxins:

• Location: Shoot tip par synthesize hote hain.
• Functions:
• Cell elongation ko promote karte hain (especially in shoots).
• Phototropism aur geotropism mein help karte hain.
• Apical dominance (terminal bud ki growth ko promote karna) mein role play karte hain.

1. Gibberellins:

• Location: Young leaves, roots, seeds.
• Functions:
• Stem elongation ko promote karte hain.
• Seed germination aur flowering mein help karte hain.

1. Cytokinins:

• Location: Rapid cell division areas mein zyada hote hain (e.g., fruits, seeds, root tips).
• Functions:
• Cell division ko promote karte hain.
• Apical dominance ko break karte hain.
• Leaves ki aging ko delay karte hain.

1. Abscisic Acid (ABA):

• Location: Leaves, fruits, seeds.
• Functions:
• Growth inhibitor hormone hai.
• Leaves ki wilting (murjhaana) ka cause banta hai.
• Seed dormancy ko induce karta hai (seed ko germinate hone se rokta hai).
• Stomata ko close karne mein help karta hai water stress ke dauran.

1. Ethylene:

• Location: Ripening fruits, aging tissues.
• Functions:
• Fruit ripening ko promote karta hai.
• Leaf abscission (leaves ka girna) mein help karta hai.

Plant hormones ek jagah synthesize hote hain aur phir diffusion ke through action site tak pahunchte hain.

Animals mein chemical coordination endocrine glands se secrete hone wale hormones ke through hota hai. Endocrine glands ductless glands hote hain, matlab ye apne secretions (hormones) ko directly blood mein release karte hain.

• Hormones blood ke through target organs tak pahunchte hain aur specific physiological processes ko regulate karte hain.
• Ye slower but widespread aur long-lasting effects show karte hain nervous system ke comparison mein.

Endocrine Glands aur Unke Hormones:

[IMAGE: TODO: Diagram of Endocrine Glands in Human Male and Female]

1. Pituitary Gland (Master Gland):

• Location: Brain ke base par.
• Hormones: Growth Hormone (GH), TSH, FSH, LH, Prolactin, ADH, Oxytocin.
• Functions: Body ki growth aur development ko regulate karta hai. Dusre endocrine glands ki activity ko control karta hai.

1. Thyroid Gland:

• Location: Neck mein, windpipe ke paas.
• Hormone: Thyroxine.
• Functions: Carbohydrate, protein aur fat metabolism ko regulate karta hai, body growth ke liye essential hai. Iodine thyroxine synthesis ke liye zaroori hai. Iodine ki deficiency se Goitre ho sakta hai.

1. Pancreas:

• Location: Stomach ke neeche.
• Hormones: Insulin aur Glucagon.
• Functions: Insulin blood sugar level ko kam karta hai. Glucagon blood sugar level ko badhata hai. Insulin ki deficiency se Diabetes hota hai.

1. Adrenal Glands:

• Location: Kidneys ke upar.
• Hormone: Adrenaline (Emergency Hormone).
• Functions: 'Fight or Flight' hormone. Stress ya danger ki situation mein body ko prepare karta hai. Heartbeat badhata hai, breathing rate badhata hai, blood flow muscles ki taraf divert karta hai.

1. Testes (Males):

• Location: Scrotum mein.
• Hormone: Testosterone.
• Functions: Male secondary sexual characteristics (e.g., voice deep hona, beard aana) aur sperm production ko control karta hai.

1. Ovaries (Females):

• Location: Abdominal cavity mein.
• Hormones: Estrogen aur Progesterone.
• Functions: Female secondary sexual characteristics (e.g., breast development) aur menstrual cycle ko regulate karta hai.

Hormones ki precise quantity mein secretion bahut zaroori hai.

Yahan kuch important animal hormones aur unke functions ka quick summary hai:

| S.No. | Hormone | Endocrine Gland | Functions

Hormones ki secretion precise quantities mein honi chahiye. Isko regulate karne ke liye body mein feedback mechanisms hote hain.

• Definition: Feedback mechanism ek self-regulating system hai jo hormone ke secretion ko control karta hai, uske level ko maintain karta hai.

Types of Feedback:

1. Negative Feedback (Most Common):

• Agar hormone ka level body mein badh jaata hai, toh ye mechanism uske secretion ko kam kar deta hai.
• Agar hormone ka level body mein kam ho jaata hai, toh ye mechanism uske secretion ko badha deta hai.
• Example: Blood sugar regulation by Insulin.
• Jab blood sugar level high hota hai, pancreas zyada insulin release karta hai.
• Insulin blood sugar ko cells mein absorb karake kam karta hai.
• Jab blood sugar level normal ho jaata hai, pancreas insulin secretion kam kar deta hai.

1. Positive Feedback (Less Common):

• Hormone ka secretion aur badh jaata hai jab uska level already high ho.
• Example: Oxytocin secretion during childbirth.

Feedback mechanism body mein hormonal balance maintain karta hai.

Animals mein control aur coordination nervous system aur endocrine system dono ke through hota hai. Dono ke apne distinct features hain:

| Feature | Nervous Control | Hormonal Control | | :---------------- | :--------------------------------------------- | :------------------------------------------------ | | Medium | Electrical impulses (neurons) | Chemical messengers (hormones in blood) | | Speed | Very fast | Slow | | Specificity | Highly specific (target cells connected by nerves) | Less specific (reaches all cells, but acts on target cells only) | | Duration | Short-lived | Long-lasting | | Effect | Localized | Widespread | | Examples | Reflex actions, muscle movements | Growth, metabolism, reproduction, stress response | | Reset time | Quick reset (can generate impulses rapidly) | Slower reset (takes time for hormone to degrade) |

• Dono systems ek dusre ke saath coordinate karte hain body ke functions ko effectively control karne ke liye.
• Nervous system quick, localized responses ke liye best hai.
• Hormonal system widespread, long-term changes aur regulation ke liye best hai.