Medical Education

1. Medical Education Memory competition?

2. Learning methods vs knowledge keeping listening = 5% reading = 10% audio-visual = 20% demonstration = 30% discussion = 50% hands-on = 75% teaching/using = 90%

3. Graduate Attributes and Capabilities Attitudes Knowledge Skills

4. Learning Philosophy I hear and I forget, I see and I remember, I do and I understand.

5. Dr. Charles Sidney Burwell(Dean of HMS from 1935 to 1949) • At an HMS graduation in the late 1940s, he said “…Half of what we have taught you is wrong. Unfortunately, we don’t know which half.” • Dr. Burwell was a cardiologist who specialized in circulation changes associated with heart disease. He is credited with bringing attention to obstructive sleep apnea syndrome. In 1944, while Dr. Burwell was Dean, women entered Harvard Medical School for the first time on an equal basis with men.

7. "It has been estimated that, from the beginning of civilization — 5,000 years ago or more — until 2003, humanity created a total of five exabytes (billion gigabytes) of information. From 2003 to 2010, we created this amount every two days. By 2013, we will be doing so every ten minutes, exceeding within hours all the information currently contained in all the books ever written. So it isn't that we need more knowledge; it is that we need to distinguish between what we know and what we don't know, through what Firestein calls “controlled neglect”. Researchers must selectively ignore vast quantities of facts and data that block creative solutions, and focus on a narrow range of possibilities. "To make discoveries, researchers need to look beyond the facts.” Ignorance includes an important discussion about scientific errors and their propagation in textbooks. I admit that I passed one on in my last book, The Believing Brain (Times Books, 2011): I repeated as gospel the 'fact' that the human brain contains about 100 billion neurons. Firestein reports that it is actually around 80 billion, and that the number of glial cells is an order of magnitude smaller than most textbooks state. The 'neural spike' recorded by neuroscientists as a fundamental unit of brain activity, Firestein reminds us, is an artefact of our measuring devices and ignores other forms of neural activity. Even the famous and widely printed 'tongue map', which shows sweet flavours sensed on the tip of the tongue, bitter on the back and salt and sour on the sides, is wrong — the result of a mistranslation of a German physiology paper. These and other errors arise as a result of our lack of scepticism towards the knowledge we have.”

8. Handheld device software • Archimedes: medical calculator • >150 equations • Unit exchange • Epocrates: drugs manual • >3300drugs • More than 45% medical doctors used • DynaMed: evidence based medicine database

9. Introduction to Human Physiology XIA Qiang, MD & PhD Department of Physiology Room 518, Block C, Research Building School of Medicine, Zijingang Campus Email: xiaqiang@zju.edu.cn Tel: 88206417 (Undergraduate school), 88208252 (Medical school)

10. Course Structure • Lectures: 80 academic hours • 5 a.h./week • 2 a.h. on Wed., 3 a.h. on Fri. • Practicals: 64 a.h. • 4 a.h./week • Begin from second week (3/3)

11. Evaluation Participation: 5% Practical reports: 15% Weekly assessments, mini-tests at lecture & midterm exam: 30% Final examination: 50%

12. Recommended textbook Widmaier EP, Raff H, Strang KT (2006 or later) Vander’s Human Physiology: The Mechanisms of Body Function, McGraw-Hill.

13. Course website • Course website: • http://m-learning.zju.edu.cn • Demo

14. Life Logic Study 生 理 学 Physiology: the study of the logic of life

15. Viral Physiology Bacterial Physiology …… Physiology Human Physiology Plant Physiology Animal Physiology

16. Human Physiology • Specificcharacteristics, functions and mechanisms of the human body that make it a living being What ? How ?

17. Body Components skin = barrier entry = respiratory & GI transport = CV & diffusion exit = renal & GI Differentiated Cells - specialized function Tissues - groups of cells with related function (muscle, nervous, connective, & epithelium) Organ- functional unit Organ system – several organs act together to perform specific function

18. ICF ISF plasma organs external environment internal environment Fluid Compartments

19. Body Fluid = 60% of Body Weight (BW) Plasma 5% of BW Extracellular Fluid 1/3, 20% of BW Interstitial Fluid 15% of BW 70 kg Male, 42 L Intracellular Fluid 2/3, 40% of BW Internal environment

20. Extracellular Fluid= Internal Environment

21. Homeostasis • Homeostasis(from the Greek words for “same” and “steady”): maintenance of static or constant conditions in the internal environment • Central theme of physiology Walter B. Cannon

22. Components of Homeostasis: • Concentration of O2 and CO2 • pH of the internal environment • Concentration of nutrients and waste products • Concentration of salt and other electrolytes • Volume and pressure of extracellular fluid

23. How is homeostasis achieved? ----Regulation Body's systems operate together to maintain homeostasis: Skin system Skeletal and muscular system Circulatory system Respiratory system Digestive system Urinary system Nervous system Endocrine system Lymphatic system Reproductive system

24. Homeostasis and Illness

25. Regulation of body functions • Nervous Regulation • Humoral Regulation • Autoregulation

26. Nervous regulation Reflex Knee jerk reflex

27. Reflex Arc • Receptor • Afferent (sensory) nerve • Reflex center (brain or spinal cord) • Efferent (motor) nerve • Effector

28. Hormone Endocrine cells Receptor Hormone Humoral regulation Traditional description of humoral regulation by hormone

29. Endocrine action:the hormone is distributed in blood and binds to distant target cells • Paracrine action:the hormone acts locally by diffusing from its source to target cells in the neighborhood • Autocrine action:the hormone acts on the same cell that produced it

30. Neuroendocrine (Neurosecretion) Vasopressin Oxytocin

32. Autoregulation Definition:Intrinsic (independent of any neural or humoral influences) ability of an organ to maintain a constant blood flow despite changes in perfusion pressure Mechanism: Stretch-activated constriction of vessels Significance: Maintenance of near-constant cerebral, renal and coronary blood flow

33. 80~180 mmHg

34. Control systems of the body CYBERNETICS or Control and Communicationin the Animal and the Machine (MIT Press 1948) Norbert Wiener (1894-1964) Originator of Cybernetics

35. Stimulus Response Control Center Effectors 1. Non-automatic Control System Open-loop system Seldom seen under physiological conditions Stress

37. Stimulus Response Control Center Effectors 2. Feedback Control System Closed-loop system Automatic control Negative feedback Positive feedback

38. Negative feedback:common A change in a condition leads to responses from the effectors which counteracts that change

39. Examples: Regulation of blood pressure, Regulation of body temperature, Regulation of hormone release…

40. Correction Gain= Error Gain of the negative feedback: The degree of effectiveness with which a control system maintains conditions

41. + Positive feedback:uncommon A change in a condition leads to responses from the effectors which amplifies that change

42. Examples: Child birth Micturition Blood coagulation Vicious circle under pathophysiological conditions…

43. Disturbance Monitor Stimulus Response Control Center Effectors 3. Feed-forward Control Often seen in nervous system Rapid Adaptive control Examples: some muscle contraction, conditioned reflex

45. Summary • Terms: • Internal environment • Homeostasis • Negative feedback • Positive feedback • Regulation of body functions

46. THANK YOU FOR YOUR ATTENTION!