生理学英文版课件.ppt

Introduction toPhysiologyXiaoqun Qin,PhD.,MD.outlinenWhat is physiology?nInternal environment and homeostasisnFunctional adjustment and control What is Physiology?Physio-bodyOlogy-mechanismIt is about the mechanism of lifePhysiology focus on normal functional activities and their control mechanism in lifeMain Method:behave observation,in vive anatomy,chronic experiment,isolated organ or tissue,cell biology,molecular biology,biophysics,simulation on computer Study scale:cellular and molecular level,organ system,integrationPrinciple thesis in physiology:nIdentity of function with structurenHomeostasis nEssential characters of life:metabolism excitability adaptation reproductionMetabolism:Exchange of matter or energy between the lives and environment,based on which the lives renew automatically.Excitability:The ability of life to response to the changes in environment(stimulus).Inhibition:activity weaken or decrease Excitation:activity strength or increase Three elements of a stimulus:intensity,duration,rateAdaptation:The character of life to adjust its inner functions according to the outer circumstance.Reproduction:Organisms or lives duplicate new lives which resemble themselves.Conceptual Organization of the Body and Organ SystemsnBlood,a crucial fluid by which the diverse organ systems communicate and exchange materials and energy.It is essential to the function of every other organ system.nCirculation system,including the heart and blood vessels,which push blood flowing in whole body.nRespiratory system,take the exchange of air between the body and the outer environment.nGastrointestinal tract,including esophagus,stomach,small and large intestines,liver,pancreas and gallbladder.Internal environmentInternal environment was firstly introduced by Claude Bernard at 1870s.It means the liquid environment in which cells live,that is,extracellular liquid.Fluid is about 60%of whole body weight,approximately two third as intracellular fluid and one third as extracellular fluid that include interstitial fluid and plasma.Homeostasis was initially termed as the state in which physical and chemical properties of internal environment keep relative steady.It is a basic condition for free and independent alive of whole body,and is essential for cells survive and activity.It is a dynamic steady state,all of function or regulation in cells or organs contribute to maintain homeostasis.(core theme)The conception has been now extended to the understanding of all physiological activities constancy.HomeostasisPositive feedbackcontroleffecteroutputfeedback message command(+)Mathematics model:dX/dt=kX (k 0)or X t+1=kXtSignificance:accelerate an functional activity reach to a needed level or a maximum the system can reach in a short time.Negative feedbackcontroleffecteroutputfeedback message command(-)Mathematics model:dX/dt=k(X0-X)(k 0)or X t+1=Xt+k(X0-Xt)(X0 is the set point)Significance:keep an functional activity toward to a stable level persistently.Feed forwardcontrollereffecteraffect message(+)commandoutput A sideway serve system that favors effecter response adequately to controlling message.Thank you for your attention.Comments or Questions?