Human Endocrine System

The endocrine system is a network of ductless glands that secrete hormones directly into the blood.
These hormones regulate vital functions like growth, metabolism, mood, and reproduction.
In Bihar, disorders like goiter, diabetes, and stunted growth are linked to poor hormonal health and nutrition.

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Major Endocrine Glands and Their Hormones

1. Pituitary Gland

• Called the "Master Gland"
• Located at the base of the brain
• Controls other glands
• Secretes:
  • Growth hormone (GH) → body growth
  • TSH → stimulates thyroid
  • FSH/LH → reproductive regulation

📝 PYQ (BPSC): Master gland of human body? → Pituitary gland

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2. Thyroid Gland

• Located in the neck
• Secretes Thyroxine
• Controls metabolism, body temperature, and growth
• Needs iodine for hormone production
• Deficiency causes goiter, cretinism in children

📝 PYQ (BPSC): Iodine deficiency causes? → Goiter
📝 Expected MCQ: Thyroid gland secretes? → Thyroxine

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3. Parathyroid Glands

• 4 small glands behind the thyroid
• Secretes Parathormone
• Regulates calcium and phosphate balance

📝 Expected MCQ: Hormone regulating calcium level? → Parathormone

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4. Adrenal Glands

• Located above kidneys
• Outer part (cortex) → secretes cortisol, aldosterone
• Inner part (medulla) → secretes adrenaline (emergency hormone)
• Adrenaline prepares body for fight or flight

📝 PYQ (BPSC): Emergency hormone? → Adrenaline

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5. Pancreas (Both endocrine and exocrine)

• Secretes:
  • Insulin → lowers blood sugar
  • Glucagon → raises blood sugar
• Failure of insulin production causes diabetes mellitus

📝 PYQ: Which hormone controls blood sugar level? → Insulin
📝 Expected MCQ: Deficiency of insulin causes? → Diabetes

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6. Gonads

• Testes (in males) → Testosterone (male traits, sperm production)
• Ovaries (in females) → Estrogen and Progesterone (female traits, menstrual cycle, pregnancy)

📝 Expected MCQ: Female hormone responsible for menstruation? → Estrogen

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7. Thymus Gland

• Located behind the sternum
• Active in children
• Secretes Thymosin
• Helps develop T-cells for immunity

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8. Pineal Gland

• Small gland in the brain
• Secretes melatonin → regulates sleep-wake cycle

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Bihar-Specific Relevance

• Goiter prevalent in iodine-deficient rural diets
• Malnutrition leads to stunted growth (GH deficiency)
• Growing incidence of diabetes due to urban dietary changes
• Lack of awareness about hormone-related issues in women (PCOD, thyroid)
• Govt initiatives:
  • Universal Salt Iodization
  • Ayushman Bharat screening for diabetes & thyroid

📝 Expected MCQ: What is done to prevent goiter in Bihar? → Iodized salt distribution

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PYQs + Expected MCQs

📝 PYQ: Which gland controls all other glands? → Pituitary
📝 PYQ: Thyroxine regulates? → Metabolism
📝 Expected MCQ: Which hormone prepares body for emergency? → Adrenaline
📝 Expected MCQ: Which gland works both as endocrine and exocrine? → Pancreas
📝 Expected MCQ: Sleep-wake cycle is controlled by? → Melatonin

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Quick Revision Points

• Glands: Ductless → Secrete hormones into blood
• Pituitary = Master gland
• Thyroid → Thyroxine → Metabolism
• Adrenal → Adrenaline → Emergency
• Pancreas → Insulin → Blood sugar
• Testes/Ovaries → Reproductive hormones
• Bihar: Goiter, stunting, diabetes → linked to endocrine issues
• Programs: Iodine salt drive, Ayushman screenings

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Sources Used

• NCERT Class 10 – Control and Coordination
• Lucent GK – Biology Section
• Drishti Science Quick Book
• Ghatna Chakra BPSC PYQs
• EduTeria Bihar Health Capsule
• Ministry of Health & Family Welfare (Iodine, NCD Reports)