Pathology

1. Pathology Concepts of Health and Disease

2. Health and Society • Prehistoric Times • Angry god or evil spirits caused illness • The gods needed to be pacified to obtain a cure • Evil spirits driven out • Communities helped to secure health of its members • Health practices were based on belief systems • Modern Western Thinking • Originating with the Greeks • No supernatural powers affecting health

3. Health and Society • Western Beliefs • Everything that can be known can be found through studying and observing science • Cortez conquering the Aztecs changed a culture’s belief in polytheism to monotheism • Diseases were thought to have been caused by emotional turmoil or grief (nervous condition) • Certain illnesses had a stigma attached • Leprosy, AIDS

5. Early Scholars • Hippocrates • 460-377BC • The foundation of clinical principles and ethics for modern medicine • Four Humors • Blood (red) from the heart = sanguine • Yellow bile from the liver = choleric • Black bile from the spleen = melancholic • Phlegm from the brain = phlegmatic

6. Aristotle • 384-322BC • Dissection of small animals • Heart was the most important organ • Center of the body • Seat of emotions

7. Galen • 129-199AD • Physician to the Emperor of Rome • Continued to do more dissections • Started experimentations on live animals • Severed a pig’s spinal cord to cause paralysis • The body carried 3 kinds of blood • Natural spirit from the liver • Vital spirit from the lungs • Animal spirit from the nerves • His work was considered infallible for 1400 years

8. Andreas Vesalius • Professor of Anatomy from Padua, Italy • 1514-1564 • Dissection of Humans (considered horrible!) • Made much more accurate drawings and diagrams

9. William Harvey • 1578-1657 • English physician and physiologist • Established blood circulates in a closed system impelled by a pump-like heart

10. Anton van Leeuwenhoek 1632-1723 Refined the microscope lens

11. Robert Hooke • Published Micrographia • Described the plant cells in cork • First to describe what a cell was

12. Antoine Lavoisier • 1743-1794 • Was actually a lawyer but devoted his life to scientific pursuits • He studied Chemistry • Came up with new ideas that allowed for the beginning of Biochemistry • He was beheaded during the French Revolution.

13. Edward Jenner • 1749-1823 • Conducted the first vaccination of cowpox on a jerseymaid • Saved a child’s life with smallpox

14. Joseph Lister 1827-1912 Concluded that microbes caused wound infections Used Carbolic acid on wounds to kill microbes Listerine

15. Florence Nightingale • 1820-1910 • Leading proponent of sanitation • Crimean War with Napoleon • Had 38 nurses with her to treat 2000 wounded and sick soldiers • She and her nurses cleaned up the hospital tents • Used hygiene on the soldiers and • Slashedthe death rate of soldiers from from 40% to 2%!!!!!!

16. Louis Pasteur • 1822-1895 • First real Bacteriologist • Studied fermentation processes • Learned how to prevent the souring of wine • “Pasteurization” • Dispelled the idea the “Miasma” or fumes was the cause of diseases

17. Robert Koch • 1843-1910 • Claimed microorganisms are the cause of illnesses • Identified the organism for tuberculosis • Discovered TB skin testing method

18. Wilhelm Rontgen • 1845-1923 • Discovered X rays

19. Paul Ehrlich • 1845-1915 • Bacteriologist • “magic bullets” could attack diseases and leave the rest of the body undamaged • He used arsenic compound (Salvarsan) as a weapon again syphilis

20. Sir Alexander Fleming • 1881-1955 • In 1928 he studied the relationship between bacteria and the mold Penicillium • Penicillium had the ability to kill Staphylocci • Not until 1940 were researchers able to use the microorganism as an antibiotic Penicillin

21. Sir Frederick Banting and Charles Best • 1921 • Discovered Insulin • Isolated insulin from the pancreas of a dog • 1922 • Successfully treated a little boy with diabetes

22. Jonas Salk • 1914-1995 • Vaccine for Poliomyelitis • Used inactivated virus vs the vaccine already in use with activated virus

23. DNA Molecule Watson and Crick DNA structure

24. Pathophysology • Pathology • From the Greek for Pathos meaning Disease • Deals with the study of the structural and functional changes in cells, tissues and organs of the body that cause or are caused by disease • Physiology • Function of the Body in the healthy state • Pathophysiology • Focuses on the mechanisms of the underlying disease and provides the background for preventive as well as therapeutic health care measures and practices

25. Disease Any deviation from or interruption of the normal structure or function of a part, organ, or system of the body that is manifested by a characteristic set of symptoms or signs

26. Etiology • The causes of disease = etiologic factors • Biological Agents • Bacteria, viruses • Physical Forces • Trauma, burns, radiation • Chemical Agents • Poisons, alcohol • Nutritional Excesses of Deficits • Most diseases are multifactorial in origins • Risk Factors • For example, heart disease or cancer

27. Pathogenesis The sequence of cellular and tissue events that takes place from the time of initial contact with an etiologic agent until the ultimate expression of a disease.

28. Morphology • Fundamental structure or form of cells or tissues • Histology

29. Clinical Manifestations • Signs v. Symptoms • Symptom • A subjective complaint that is noted by the person with a disorder • Sign • A manifestation that is noted by an observer

30. Diagnosis • The designation as the the nature or cause of a health problem • Requires history and physical examination • Differential Diagnosis • A systematic method used to identify unknowns. This method, essentially a process of elimination

31. Diagnosis • Normality • An important factor when interpreting diagnostic test results is the determination of whether they are normal or abnormal • Reliability • The extent to which an observation is repeatable • Validity • The extent to which a measurement tool measures what is intended to measure • Sensitivity • The proportion of people with a disease who are positive for that disease on a given test or observation • Specificity • The proportion of people without the disease who are negative on a given test or observation • 95% accurate v. 100%

32. Morbidity and Mortality • Mortality • Death statistics • Morbidity • The effects of an illness has on a person’s life • Concerned not only with the occurrence and incidence of the diseases but also the long-term impact of the disease

33. Risk Factors • Conditions suspected of contributing to the development of a disease • Studies to determine risk factors • Cross-sectional studies • Simultaneous collection of information for classification of exposure and outcome • Case-control studies • Compares persons known to have the outcome of interest and those known not to have the outcome of interest • Cohort studies • Group of persons who were born at approximately the same time or share some characteristics of interest • Longitudinal studies • A cohort is studies over a period of time

34. Framingham Study • Framingham Massachusetts • In 1948, the Framingham Heart Study embarked on an ambitious project in health research to identify the common factors that contribute to cardiovascular disease by following its development over a long period of time in a large group of participants. • 5000 people between 30 and 59 years of age • Followed for 20 years • Looking at coronary artery disease

35. Prognosis Probable outcome and prospect of recovery from a disease

36. Levels of Prevention • Primary • Keeping disease from occurring by removing risk factors • Secondary • Detect disease early when it is still asymptomatic • Pap smears • Tertiary • Clinical interventions that prevent further deterioration or reduces the complication of a disease once it is diagnosed