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Guoqing WANG M.D.& Ph.D.,Associate Professor Tutor of Master`s Degree E-mail:wangguoqing@suda.edu.cn Tel:0512-62096158; 13506212030 PC: 215123. What will we discuss in this chapter? (Outline). § Section 1. Study § Section 2 . Internal environment § Section 3 . Regulation
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Guoqing WANG M.D.& Ph.D.,Associate Professor Tutor of Master`s Degree E-mail:wangguoqing@suda.edu.cn Tel:0512-62096158; 13506212030 PC: 215123
What will we discuss in this chapter? (Outline) § Section 1. Study § Section 2 .Internal environment § Section 3 .Regulation § Section 4.Control system
What is bilingual teaching? It means the use of a second or foreign language in school for the teaching of content subjects. (罗敏华, 姚孟晖, 文质, 舒明星. 医学双语教学的初探. 中国现代医学杂志, 2003, 13(24): 156~157)
Mastering of a foreign language provides one key more to open the door of medical science! To young university students in training
Knowledge Filling In Your BrainLet You Be Intelligent May Be Like That, Which Will Be Useful ……
Physiology Department of Physiology, Medical School, Soochow University 2008 . 8
Curriculum Introduction in Brief Physiology is a science which aims at rule of the life activity and function of the constitutive parts of organism as studying object. It is also one of the medical compulsory basic subjects and what it tells learner is the component parts of the medical license examination. This subject consists of theoretical and experimental lessons and the former mainly talks about the function and regulation of cell, blood, circulation, respiration, digestion, sense organ, nervous system, endocrine system, reproduction, etc, while the latter is involved in primary physiological experiment in order to improve students` practical ability.
Chapter 1 Introduction
Human Being`s Need Self realized Need Considered Need Sociable Need Safe Need Physiological Need It may be like illustrated above……
Physiology: • definition:It is a study of the normalfunctions of organs and organ systems of the body, the mechanisms by which they are achieved and the regulation of their activities. (biological science) • object:living organisms (animal, plant, human being) • Relations with medicine : • animal experiments 、clinical studiesphysiology • illness studies physiology • clinical studies physiology pile base checkout、abundance
Physiology • Physiology is one of the important basic medical sciences and the foundation of medical practice. • To learn physiology is indispensable not only for the study of successive courses, but also for students' future professional career after graduation. • Physiology is a branch of the biology. • It is a science that studies the vital regularity in living organisms. • Why do we study Physiology? • Understand the physiologic principle underlie normal function in order to cure the impairments.
§ Section 1.Study • task • level • method
Task Human physiology • the functions • the mechanisms • the affecting factors and regulation PHYSIOLOGY = THE LOGIC OF LIFE
Level • cell and molecule • ——cell physiology or general physiology • organ and system • ——organ physiology • whole body • ——integrative physiology Evidenced by experimentation
Development of the physiology • In the eighteenth and nineteenth centuries, physiology made great progress at the level of organs and systems . • In the twentieth century, it gained knowledge rapidly at the cell and molecular levels. • Now, in the twenty-first century, the challenge for physiology is to integrate information at all levels towards a deeper understanding of mechanisms and function.
Different Level of Physiological Research Organization of the human body Organisms (Human body) Organ systems Organs Tissues Cells
Method • animal experiments • chronic experiments:chronic experiments may be performed on a conscious subject for a long period of time • in vivo :a manipulation performed on the whole body is called an experiment in vivo • acute experiments :experiment performed on animals under anesthesia or with transection of the brain is called acute experiment. • in vitro:studies on isolated tissues or organs involve experiments in vitro • human experiments • lab observation and research notice: ① difference between human and animal; ② difference between chronic experiments and acute experiments
§ Section 2.Internal environment** ☆body fluid=60% BW intracellular fluid: 40% (2/3) extracellular fluid : 20% (1/3) plasma: 5% interstitial fluid:15% ☆ internal environment all cells of the body are surrounded by extracellular fluid, extracellular fluid is called the internal environment of the body. ☆internal environment---- extracellular fluid cell ECF external environment internal environment ☆characteristic: dynamic equilibrium
Homeostasis ** • definition: • homeostasis is the maintenance of a constant state with special reference to the internal medium. • significance: • for maintenance of normal cell function. • How to maintain it? • The various physiologic arrangements which serve to restore the normal state, once it has been disturbed.
Homeostasis & control • successful compensation • homeostasis reestablished • failure to compensate • pathophysiology • illness • death
§ Section 3.Regulation * • definition: • the ability of an organism to maintain a stable internal conditions in a constantly changing environment • three types: • nervous regulation • humoral regulation • autoregulation
Nervous regulation • nervous regulation:many physiological activities are regulated by the nervous system • pathway——reflex:a reflex is the basic unit of nervous regulation • unconditioned reflex • conditioned reflex • reflex arc:the reflex arc is the pathway in a reflex • consisting of sense organ, afferent and efferent nerves, interneurons and effector • character: (1) distance: short (local); (2) speed: fast; (3) distribution: focused (accurate)
difference ? (conditioned reflex) (unconditioned reflex)
Humoral regulation • humoral regulation:chemical substances secreted by some tissues arrive at target organs through body fluids and regulate physiological activity of the target organ • hormone • endocrine • paracrine • neurosecretion • character: (1) distance: long( permanent); (2) speed: slow; (3) distribution: diffuse.
Nervous- humoral regulation • nervous- humoral regulation : • In many cases, the endocrine system is so closely related to the nervous system that it can be regarded as an extension of the efferent limb of the reflex arc . In this instance it is called nervous-humoral regulation. • difference between nervous and humoral regulation • two languages of communication are chemical and electrical. • nervous regulation: electrical • humoral regulation: chemical • characteristics of communication are distance, speed, distribution
Autoregulation • autoregulation: • In certain cases, a tissue or organ can respond directly to the environmental change, depending neither on nervous nor on humoral control. This form of regulation is called autoregulation. • character: • local; limited • example: • autoregulation of renal blood flow • autoregulation of cerebral blood flow
§ Section 4.Control system • non-automatic control system • feedbackcontrol system • feed-forward control
Non-automatic control system • non-automatic control system: • non-automatic control system is a flow of information along open loop system,hand out command from controller to effector ,it is unidirectional. controller effector • character: • It is few in normal physiological regulations.
FeedbackControl System • feedbackcontrol system: feedback is a flow of information along a closed loop, a constancy of physiological variable requires a feedback mechanism that feeds the output information back to the control system so as to modify the nature of control. automatic control 反馈
Stimulus Sensor Feedback Messages Afferent Nerve Feedforward Messages Central Controlling System Efferent Nerve Effector Controled System Reaction Feedback Controlling And Feedforward System
Negative feedback ** • negative feedback: a regulated variable is sensed, information is sent to a controller, and action is taken to oppose change from the desire value. • homeostasis is the maintenance of a constant state because of existence to the negative feedback. • set point resetting • example:regulation of blood pressure、regulation of breathing、regulation of body temperature • significance : maintenance of the homeostasis
Positive feedback • positive feedback: With positive feedback, a variable is sensed and action is taken to reinforce change of the variable, so it promotes a change in one direction. • example:childbirth、blood coagulation、 defecation reflex、 micturition reflex、bleedingetc. • importance : ① It can not maintain the homeostasisand destroy the homeostasis ② It is more in pathology (vicious circle) to keep the functional activity going on until its end.
Feed-forward control • feed-forward control:feed-forward control mechanisms often sense a disturbance and can therefore take corrective action that anticipates changes 。 • example: • regulation of cardiovascular activity before movement • shivering before diving into the cold water • function :the body can adapt the variable environment • ① sense disturbance and avoid disturbance; • ② take adaptive response
Summarization PLEASE TAKE DOWN
Summary 1COMPONENTS OF A HOMEOSTATIC SYSTEM Feedforward Controller Set Point Integration Center Effector Regulated Variable Sensor
Summary 2CHARACTERISTICS OF HOMEOSTASIS • Effectors may have opposing actions. • Negative feedback is the process that prevents change. • Positive feedback is the process that perpetuates change. • Feedforward control is outside stimuli that alter the normal feedback response.
Supplementary knowledge:The basic characteristics of life activity. • metabolism • The term "metabolism", meaning literally "change", is used to refer to all material and energy transformations that occur in the body • excitability • Excitation signifies an increase in activity • adaptability • When a maintained stimulus of constant strength is applied to a receptor, the frequency of the action potential in its sensory nerve decreases over time • reproduction • The process of reproduction includes fertilization, pregnancy and delivery.
Consideration after class 【本章节问题思考】 1. Please describe the patterns and characteristics of Human physiological regulation. 2. What are the basic characteristics of life?
Guide of Reference【本章节学习参考书单】 1. 姚泰主编. 生理学. 第五版. 北京: 人民卫生出版社, 2000. 2. 范少光, 汤浩, 潘伟丰主编. 人体生理学(二版). 北京: 北京医科大学出版社, 2000. 3. 贺石林, 李俊成, 秦晓群主编. 临床生理学. 北京: 科学出版社, 2001. 4. 王志均, 陈孟勤主编. 中国生理学史. 北京: 北京医科大学, 中国协和医科大学联合出版社, 1993. 5. 王庭槐. 禁不住的真理之光. 医学与哲学, 1981, 2: 28~30. 6. 王庭槐主编. 生理学. 全国高等学校医学规划教材, 北京: 高等教育出版社, 2005. 7. Berne RM, Levy MN, Koeppen BMI, Stanton BA. Physiology, 5th ed, St Louis: Mosby Electronic Production, 2004. 8. Guyton AC, Hall JE. TEXTBOOK OF MEDICAL PHYSIOLOGY, 10th ed, Philadelphia: W.B. Saunders Co, 2000. 9. Charles Seidel. BASIC CONCEPTS IN PHYSIOLOGY: a student’s survival guide (Great for Course Prep and USMLE), Houston: McGraw-Hill Co Inc, 2002. 10. Fox SI. Human physiology, 7th ed, New York: McGraw-Hill Co Inc, 2002.