Introduction to Human Physiology

1. Introduction to Human Physiology XIA Qiang, M.D. & Ph.D. Department of Physiology Room 518, Block C, Research Building School of Medicine, Zijingang Campus Email: xiaqiang@zju.edu.cn Tel: 88208252

2. Course Structure • Lectures: 80 academic hours • 5 a.h./week • 2 a.h. on Tue., 3 a.h. on Fri. • Practicals: 64 a.h. • 4 a.h./week

3. Evaluation Participation in practicals: 5% Practical reports: 15% Weekly assessments & midterm exam: 20% Final examination: 60%

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

5. Course website • University Course Center: • http://10.202.77.12/ • Course website: • http://10.202.77.12/JWCenterWeb/TemplateView?tempName=null&id=null&websiteId=26519&type=1&codeName=columnsun&courseWebsiteId=69995

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

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

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

9. Exercise Physiology

10. Aviation, high-altitude, and space physiology

11. Diving and Hyperbaric physiology

12. History of Physiology C. Galen (129-200) (Ancient Greco-Roman)

13. Leonardo da Vinci (1452-1519) (Italian)

14. Rise of modern physiology De Motu Cordis “On The Motion Of The Heart And Blood In Animals” (1628) (http://www.fordham.edu/halsall/mod/1628harvey-blood.html) W. Harvey (1578-1657) (English)

15. An Italian physiologist who used a microscope to discover the capillaries, crowning Harvey’s investigation M. Malpighi (1628-1694)

16. L. Galvani (1737-1798) (Italian)

17. A French physiologist known for his idea of theinternal environment (1813-1878)

18. A Russian physiologist known chiefly for his development of the concept of the conditioned reflex Awarded the Nobel Prize for Physiology or Medicine in 1904 Павлов (Ivan Pavlov) (1849-1936)

19. 中国生理学会 Chinese Association for Physiological Sciences (founded in 1926) 林可胜(Robert Kho Seng Lim)(1897-1969) “Father of Chinese Modern Physiology”

20. Levels of Physiological research

21. 1.3 340/380 0.6 5s 5s Measurement of [Ca2+]i 120 Cell length (m) 90 Measurement of cell shortening 1. Cellular and molecular Physiology

23. 2. Organ and System Physiology

24. 3. Integrative Physiology Acute experiment

25. Chronic experiment

26. 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

27. Plasma 5% of BW Extracellular Fluid 1/3, 20% of BW Interstitial Fluid 15% of BW Internal Environment External Environment

28. Extracellular Fluid= Internal Environment

29. Homeostasis Homeostasis(from the Greek words for “same” and “steady”): maintenance of static or constant conditions in the internal environment W. Cannon

30. 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

31. 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

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

33. Nervous regulation Reflex Knee jerk reflex

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

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

36. 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

37. Neuroendocrine (Neurosecretion) Vasopressin Oxytocin

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40. 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

41. 80~180 mmHg

42. 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

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

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

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

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

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

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

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

50. 3. Feed-forward Control Often seen in nervous system Rapid Adaptive control Examples: some muscle contraction, conditioned reflex