Chapter 1 Major Themes of Anatomy & Physiology • Form and Function • Origins of Biomedical Science • Scientific Method • Human Origins and Adaptations • Human Structure • Human Function • Language of Medicine Anatomy - The Study of Form • Observation of surface structure • Cadaver dissection is cutting & separation of organs to study their relationships • Comparative anatomy is the study of more than one species to analyze evolutionary trends • Physical examination – palpation, auscultation, percussion • Gross anatomy is what is visible with naked eye • Histology is examination of cells with microscope Early Anatomical Drawings Physiology - The Study of Function • Study of bodily functions by use of methods of experimental science • Comparative physiology involves the study of different species – Basis for the development of new drugs and medical procedures • Anatomy is what shapes there are, Physiology is what those shapes do Beginnings of Medicine • Physicians in Mesopotamia & Egypt 3000 years ago used herbal drugs, salts & physical therapy • Greek physician Hippocrates established a code of ethics & urged physicians to seek causes of disease • Aristotle called causes for disease physiologi & said that complex structures are built from simpler parts • Galen, physician to the Roman gladiators, saw science as a method of discovery – did animal dissections since use of cadavers banned – wrote book advising followers to trust their own observation Birth of Modern Medicine • Vesalius published accurate gross anatomy atlas (1543) • Leeuwenhoek invented microscope to look at fabrics (1632-1723) • Hooke (1665) and Zeiss (1860) developed & improved compound microscope (described plant cell walls in 1665) • Schleiden & Schwann thought that all organisms were composed of cells -- cell theory of 1839 • Clinical practice was in dismal state – bleeding to remove toxins, operate with dirty hands, no anesthesia for amputations Early Microscopes Living in a Revolution • Pioneers in 19th & 20th centuries – established scientific way of thinking – replaced superstition with natural laws – momentous discoveries • germ theory of disease • heredity & structure of DNA • Now at threshold of modern biomedical science – technology enhanced diagnostic ability & life-support strategies – genetic revolution --library of the molecular structure of every human gene is finished • Gene therapy being used to treat disease Scientific Method • Bacon (1561-1626) and Descartes (1596-1650) – were not scientists but did invent new habits of scientific thought • scientific method as habits of disciplined creativity, careful observations, logical thinking & analysis of observations • way of seeking trends & drawing generalizations • Convinced governments of England & France to form academies of science that still exist today • Scientific way of thinking based on assumptions & methods that are reliable, objective & testable Making observations until capable of drawing generalizations and making predictions – anatomy is a product of inductive method • Proof in science can not go past “proved beyond reasonable doubt” – reliable methods of observation – tested and confirmed repeatedly – not falsified by any credible observation • In science, all truth is tentative Inductive Method Hypothetico-Deductive Method • Physiological knowledge gained by this method • Ask a question and formulate a hypothesis -- an educated possible answer • Good hypothesis – consistent with what is already known – capable of being tested and falsified with certain evidence • If nothing could prove it wrong, it is not a scientific belief • Hypotheses are written as IfThen predictions – modified and rewritten after testing Experimental Design • Sufficient sample size to prevent chance event • Control group and treatment group receive the same treatment except for the variable being tested • Prevention of psychosomatic effects – use of placebo in control group • Experimenter bias – prevented with double-blind study • Statistical testing to be sure the difference between groups was not random, but was due to variable being tested Peer Review • Critical evaluation by other experts in the field – prior to funding – verification and repeatability of results • Ensures honesty, objectivity & quality in science Health Minister Manto Tshabalala-Msimang of South Africa, known for putting vegetable remedies ahead of anti-retrovirals, endorses Dr Matthias Rath's vitamin treatments. Dr. Rath and his cure for AIDS: Mega Doses of Vitamin C • A doctor who worked with Nobel Prize winner Linus Pauling • has taken the advocacy of vitamins into all-out war on the pharmaceutical companies • Buys ad space in the NY Times, and fills them with editorials masked as facts • Without getting confirmation of his studies is taking his cure to the people of Africa • Problems: Too much Vitamin C can lead to Diarrhea which can kill an AIDS patient. Facts, Laws and Theories • Scientific fact is information that can be independently verified by any trained person – iron deficiency leads to anemia • Law of nature is a description of the way matter and energy behave – resulting from inductive reasoning & repeated observations – written as verbal statements or mathematical formulae • Theory is a summary of conclusions drawn from observable facts – it provides explanations and predictions – sliding filament theory of muscle contraction Logic is the anatomy of thought -John Locke • Conditional arguments: the basis of hypothesis forming. Two parts • Part 1: If p then q – P = antecedent – Q = Consequent • Part 2 allows us to draw conclusions – If P happens then Q happens (Modus Ponens – If Q did not happen, P did not happen (Modus Tollens) There is a claim that lycopene, the reddish substance in tomatoes and peppers, is of value in protecting people from Alzheimer Disease. How would you, as a scientist, go about substantiating or refuting this suggestion?