##Semester I

##Module I: Human and Medicine

##Lesson 2: 🧪 II. Dawn of Scientific Medicine

The period after 1500 A.D. marked a turning point in medical history, characterized by political, industrial, religious, and medical revolutions. Medicine evolved rapidly alongside changes in society, science, and human thinking.

⚔️ Political revolutions in France and America led people to claim civil rights.
🏭 The Industrial Revolution improved living standards in the West while also creating new health challenges.
🧠 Medicine advanced in parallel with growing civilization and scientific thought.

#🌱 1. Revival of Medicine (1453–1600 A.D.)

This era marked a shift from dogma and authority toward individual scientific inquiry and rational research.

#🧠 Paracelsus (1493–1541)

• Strongly criticized Galen and Avicenna

• Publicly burned their works

• Opposed superstition and promoted rational medical thinking

#🧪 Fracastorius (1483–1553) — Founder of Epidemiology

• Proposed the theory of contagion

• Suggested diseases spread by invisible particles

• Identified person-to-person transmission of syphilis

#🫀 Andreas Vesalius (1514–1564)

• Performed systematic human dissections

• Exposed errors in Galen’s anatomy

• Authored “Fabricá”, a classic anatomical text

• Known as “the first man of modern science”

#🩺 Ambroise Paré (1510–1590) — Father of Surgery

• Improved surgical techniques

• Emphasized practical and humane methods

• Later, John Hunter (1728–1793) introduced scientific principles into surgery

#🧍‍⚕️ Thomas Sydenham (1624–1689) — “English Hippocrates”

• Advocated clinical observation

• Developed differential diagnosis

• Considered an early epidemiologist

#💡 Key Discoveries (17th–18th Century)

• 1628 — William Harvey: Circulation of blood

• 1670 — Leeuwenhoek: Microscope

• 1796 — Edward Jenner: Smallpox vaccination

• 1682–1771 — Morgagni: Founder of pathologic anatomy

These discoveries laid the foundations of modern scientific medicine.

#🧼 2. The Great Sanitary Awakening (Mid-19th Century)

A major milestone in the evolution of public health.

🏭 Industrialization led to slums, overcrowding, poor sanitation, and high mortality.

🧍 Life expectancy in London (1842):

• Gentry: 44 years

• Working class: 22 years

#💥 1832 — Cholera Epidemic

• Triggered urgent public health reforms

⚖️ Edwin Chadwick (1800–1890)

• Investigated urban living conditions

• Published the Sanitary Report (1842)

• Exposed appalling health conditions

🧼 Led to:

• Public Health Act 1848

• Anti-filth movements

• Recognition of state responsibility for health

#🌍 3. Rise of Public Health (Mid–Late 19th Century)

#🧠 Johann Peter Frank (1745–1821)

• Proposed that the state is responsible for people’s health

• His vision realized through the Public Health Act 1848

#🚰 John Snow (1813–1858)

• Studied cholera outbreaks (1848–1854)

• Linked cholera to contaminated water, not miasma

• Founder of modern epidemiology

#💧 William Budd (1856)

• Demonstrated typhoid transmission through drinking water

#🧑‍⚕️ Sir John Simon (1816–1904)

• First Medical Officer of Health of London

• Developed a model public health system

🏛️ Public Health Act 1875

• Regulated sanitation, water supply, and environment

🌎 Movement spread to:

• USA (Lemuel Shattuck, 1850)

• Europe

📌 1880–1920 known as the “Disease Control Phase” of public health.

#🦠 4. Germ Theory of Disease (1860 onwards)

#🔬 Louis Pasteur (1822–1895)

• Demonstrated bacteria in air

• Disproved spontaneous generation (1860)

• Proposed germ theory of disease (1873)

#🧪 Robert Koch (1843–1910)

• Proved anthrax was caused by bacteria (1877)

• Established bacteriology as a science

#🧬 Key Discoveries

• Gonococcus — 1879

• Typhoid bacillus, Pneumococcus — 1880

• Tubercle bacillus — 1882

• Cholera vibrio — 1883

• Diphtheria bacillus — 1884

👉 This era marked the Golden Age of Bacteriology, making medicine truly scientific.

#🛡️ 5. Birth of Preventive Medicine (18th–19th Century)

#🌿 James Lind (1716–1794)

• Advocated fruits and vegetables to prevent scurvy (1753)

#💉 Edward Jenner (1749–1823)

• Introduced vaccination against smallpox (1796)

🩺 Marked the beginning of specific disease prevention.

#🧠 After Germ Theory

• 1883 — Anti-rabies treatment (Pasteur)

• 1892 — Cholera vaccine

• 1894 — Diphtheria antitoxin

• 1898 — Anti-typhoid vaccine

• 1827–1912 — Development of antiseptics & disinfectants

#🦟 Transmission Discoveries

• 1896 — Bruce: Sleeping sickness & tsetse fly

• 1898 — Ross: Malaria & Anopheles mosquito

• 1900 — Walter Reed: Yellow fever & Aedes mosquito

🧪 Laboratory methods enabled early diagnosis and disease control.
Initial focus was on infectious disease control, preceding modern levels of prevention.

#✅ Summary Table