SSC Biology 2025 | SSC Biology Digestive System Or Hormones | SSC Biology By Bhawna Ma'am

Endocrine System Fundamentals
📌 The study of the Endocrine System is called Endocrinology.
👨‍🔬 The Father of Endocrinology is recognized as Thomas Addison.
🧪 The endocrine system is comprised of glands and hormones, which are secreted directly into the bloodstream.

Types of Glands
💧 Exocrine (बाह्य स्त्रावी) Glands: Secrete substances outside the body or into ducts; also known as Duct Glands.
🚫 Endocrine (अंतः स्त्रावी) Glands: Secrete hormones directly into the blood; also known as Ductless Glands.
🔄 Mixed Glands (मिश्रित ग्रंथि): Function as both exocrine and endocrine glands.

Exocrine Gland Examples & Functions
🥇 The Liver (यकृत) is the largest exocrine gland; it secretes bile juice (पित्तरस) which enters the small intestine via a duct.
💧 Lacrimal Glands (अश्रु ग्रंथि/Tear Glands) are the smallest exocrine glands and produce tears.
🥛 Mammary Glands (दूग्ध ग्रंथि) are responsible for milk secretion.
🔥 Sweat Glands (पसीना ग्रंथि/श्वेत ग्रंथि) secrete sweat, with the highest concentration found in the underarms and palms.
🧴 Oil Glands (तेलीय ग्रंथियां) secrete sebum, and excessive sebum consumption by bacteria leads to pimples (मुहांसे).

Endocrine Gland Examples & Hormone Functions
🧠 The Pituitary Gland (पीयूष ग्रंथि) is the Master Gland, controlling other glands, and is located just below the hypothalamus in the brain.
🤏 The Pineal Gland (पीनियल काय) secretes Melatonin, which controls the biological clock (waking and sleeping cycles).
👑 The Thyroid Gland (अवटु ग्रंथि) is the largest endocrine gland; it is butterfly-shaped and requires Iodine for its hormone, Thyroxine, to function.
* Thyroxine deficiency causes Goiter (गले का घेंघा), while excess causes Exophthalmic Gout (आंखों का घेंघा) or Graves' Disease (ग्रेव रोग).
* Calcitonin, secreted by the thyroid, balances calcium levels, preventing kidney stones (formed from Calcium Oxalate).
⚙️ Pancreas (अग्नाशय ग्रंथि) is the only mixed gland in the body and is leaf-shaped.
* Its Islets of Langerhans contain:
* Alpha Cells secreting Glucagon (increases blood sugar).
* Beta Cells secreting Insulin (decreases blood sugar).
* Gamma/Delta Cells secreting Somatostatin (inhibits growth).
* F Cells forming Pancreatic Juice (digestive enzymes).
* The Pancreas is also the only mixed gland.

Pituitary Hormones Details
* Anterior Pituitary (अग्र भाग) secretes ACTH, FSH, LH, TSH, and GH (Growth Hormone).
* GH (Growth Hormone) controls growth; excess causes Acromegaly (भीमकायता), deficiency causes Dwarfism (बोनापन).
* Posterior Pituitary (पश्च भाग) secretes ADH (Anti-diuretic Hormone, also called Vasopressin), which controls urine formation, and Oxytocin.
* Oxytocin is known as the Love Hormone; it initiates labor pain (प्रसव पीड़ा) by causing uterine wall contractions and stimulates milk production after delivery.

Adrenal & Gonadal Hormones
🐅 The Adrenal Glands (अधिवृक ग्रंथि) are located above the kidneys (two in number) and secrete Adrenaline.
🚨 Adrenaline is known as the Emergency Hormone or the "Fight or Flight" (लड़ो या उड़ो) Hormone (3F: Fight, Flight, Fear).
👨 Testes (वृषण) secrete Testosterone (Male Hormone), controlling secondary sexual characteristics and spermatogenesis.
👩 Ovaries (अंडाशय) secrete Estrogen, which brings about female secondary sexual characteristics.

Thymus Gland
🧒 The Thymus Gland (बाल्य ग्रंथि) is located between the lungs and shrinks with age.
🛡️ It secretes Thymosin, which is crucial for the maturation of White Blood Cells (WBCs).

Key Points & Insights
➡️ The study of the Endocrine System is Endocrinology, and its Father is Thomas Addison.
➡️ Exocrine glands use ducts to secrete (e.g., Liver secreting bile via a duct), while Endocrine glands secrete directly into the blood (Ductless Glands).
➡️ The Pancreas is the body's only mixed gland; its Beta cells produce Insulin to decrease blood sugar, and Alpha cells produce Glucagon to increase it.
➡️ Oxytocin is the "Love Hormone" responsible for uterine contractions during childbirth and milk secretion post-delivery.
➡️ Adrenaline is the "Fight or Flight" hormone, released during stress or fear.

📸 Video summarized with SummaryTube.com on Feb 20, 2026, 10:11 UTC