生理學(xué)課件：生理緒論

1、Physiology （生理學(xué)）Introduction (緒論)Why must the medical students study human physiology?Human physiology is the main component in the study of medicine. For example: why can heart automatically beat? When a patient is in a hospital, their physiology has gone wrong. Medical science development is close

2、ly related to physiology. Physiology provides the theories to explain many diseases. Clinical practices test whether the physiological theories are correct or not and promote development of physiology.Methods of physiological research 生理學(xué)的研究方法促胰液素的發(fā)現(xiàn)（Bayliss & Starling， 1902）Physiology is an experim

3、ental scienceOtto Loewi (奧托 . 洛伊維 ) 1936 Nobel PrizeAcute experiment in vitro (急性離體實(shí)驗(yàn)) at organic levelAcute experiment in vitro at tissue/molecular levelChronic experiment in vivo人體實(shí)驗(yàn)Levels of physiological research生理學(xué)研究的不同水平(2) Cellular & molecular level （General Physiology， Cellular and Molecular

4、 Physiology） 細(xì)胞和分子水平The basic living unit of the body is the cell, and each organ is an aggregation of many different cells held together by intercellular supporting structures. Help to understand the function of the organ. Organic & systemic level （Organ Physiology） 器官和系統(tǒng)水平The goals are to explore

5、the effects of organs and systems for human body and how to perform their activities, and the affecting factors. (3) Integrative level （Integrative Physiology） 整體水平 The aims are to study interactions among organs and systems, and interaction between human body and environment.Translational Medicine第

6、二節(jié) 機(jī)體的內(nèi)環(huán)境和穩(wěn)態(tài)Internal environment and HemeostasisOrgan Systems are Integrative. All of the systems in an organism are interconnected. 體液的分隔和相互溝通The Bodys External Environment(外環(huán)境)Interior of body separated from external environment by a layer of epithelial tissue. Example: Lumen of respiratory system

7、The Bodys Internal Environment 內(nèi)環(huán)境Internal environment = fluid surrounding cells= Extracellular fluid Claude Bernard 1852年提出Homeostasis (穩(wěn)態(tài))Minority of mammalian cells are in direct contact with external environmentMajority of cells are sheltered by extracellular fluidWhen conditions outside the bod

8、y change, this is reflected in the composition of the ECF, this in turn affects the cellsHomeostasis - the ability to maintain a relatively stable internal environment in an ever-changing outside world. “Relatively stable” means that the internal environment of the body is in a dynamic state of equi

9、librium. Does not mean that composition, temperature, and other characteristics are absolutely unchangingHomeostasis is essential for survival and function of all cellsU.S.A Physiologist Walter Cannon combined “Homeo” with “stasis” to make up the term, Homeostasis. To keep cells under optimum condit

10、ions for function and survivalWhy do we need a stable, internal environment?Living cells can function only within a narrow range of such conditions as temperature, pH , ion concentrations, and nutrient availability, yet living organisms must survive in an environment where these and other conditions

11、 vary from hour to hour, day to day, and season to season. Organisms therefore require mechanisms for maintaining internal stability in spite of environmental change. So, there is a set point. The internal environment can be altered around the set point within a tolerable (narrow) range of values. T

12、his is what happens in your body. When the deviation is too great, the body has to detect it first, and then correct it. Homeostasis-the key concept to physiological control. A Central Organizing Principle of PhysiologyHomeostasis is the physiological process that maintains equilibrium in our physio

13、logical activity and allows us to function normally. One of the primary prerequisites for being a healthy individual is the ability to maintain homeostasis。 Deviations from the normal values are indicators of abnormal function Normal Values Neuroregulation（神經(jīng)調(diào)節(jié)） * Definition & the characteristics *

14、Reflex & reflex arc Humoral regulation（體液調(diào)節(jié)） * Definition & the characteristics * Hormone & its secretory forms Telecrine, paracrine, neurosecretion, etc. Autoregulation（自身調(diào)節(jié)） * Definition & the characteristics第三節(jié) 機(jī)體生理功能的調(diào)節(jié)Regulation of physiological functionControls and coordinates bodily activitie

15、s that require rapid responsesDetects and initiates reactions to changes in external environmentIt is completed under CNS by reflex that the regular response was made to internal or external stimuli under CNS.Reflex arc:Sensor, afferent neuron, reflex center, efferent neuron, and effector.Neuroregul

16、ation （神經(jīng)調(diào)節(jié)）有些內(nèi)分泌腺本身直接或間接地受到神經(jīng)系統(tǒng)的調(diào)節(jié)，在這種情況下，體液調(diào)節(jié)是神經(jīng)調(diào)節(jié)的一個(gè)傳出環(huán)節(jié)，是反射傳出道路的延伸。這種情況可稱為神經(jīng)-體液調(diào)節(jié)。神經(jīng)體液調(diào)節(jié)實(shí)例： 腎上腺髓質(zhì)受交感神經(jīng)節(jié)前纖維的支配，交感神經(jīng)興奮時(shí)，引起腎上腺髓質(zhì)釋放腎上腺素和去甲腎上腺素，從而使神經(jīng)與體液因素共同參與機(jī)體的調(diào)節(jié)活動(dòng)。 Neurohumoral regulation(神經(jīng)-體液調(diào)節(jié)) Many endocrine glands are not independent on nervous system, they are regulated directly or indirectl

17、y by nervous system, so the humoral regulation is believed as one loop of nervous system, i.e. Neurohumoral regulation . Arterial blood pressure contraction of the vascular smooth muscle constriction of the blood vessel the blood flow relatively constantThe regulation is not dependended on nervous s

18、ystem or homoral regulation. The cells or tissues themselves can response to stimulus.腎動(dòng)脈灌注壓在80-180mmHg范圍變動(dòng)時(shí)，腎血流量基本保持穩(wěn)定，從而保證腎泌尿活動(dòng)在一定范圍內(nèi)不受動(dòng)脈血壓改變的影響。Range of regulation BP: 80 180 mmHg血流阻力同微小動(dòng)脈管半徑的四次成反比，說明血管口徑只要稍有縮小,其阻力就大大增加。生理功能的調(diào)節(jié) 神經(jīng)調(diào)節(jié)（neuroregulation） 1概念:由神經(jīng)反射參與的調(diào)節(jié) 2基本方式：反射（reflex） 1）概念:在中樞神經(jīng)系統(tǒng)參與下

19、，機(jī)體對(duì)刺激發(fā)生的規(guī)律性反應(yīng) 2）結(jié)構(gòu)基礎(chǔ)（反射弧） 3）分類 3作用特點(diǎn) 體液調(diào)節(jié)（humoral regulation）1概念: 體液因子(激素,化學(xué)物質(zhì)) 體液途徑器官組織2作用方式 3作用特點(diǎn) 4神經(jīng)與體液調(diào)節(jié)比較 自身調(diào)節(jié)（autoregulation） 1概念：組織細(xì)胞不依賴于神經(jīng)或體液調(diào)節(jié)而產(chǎn)生的適應(yīng)性反應(yīng)。2舉例：腦血流量調(diào)節(jié); 腎血流量調(diào)節(jié)3特點(diǎn)：涉及范圍小;調(diào)節(jié)幅度小作 用機(jī)體調(diào)節(jié)的主要方式,起主導(dǎo)作用反應(yīng)速度迅速作用部位準(zhǔn)確作用范圍局限持續(xù)時(shí)間短暫 反應(yīng)速度緩慢 作用部位廣泛 作用范圍彌散 持續(xù)時(shí)間持久 Homeostasis is continually being d

20、isrupted byExternal stimuli heat, cold, lack of oxygen, pathogens, toxinsInternal stimuliBody temperatureBlood pressureConcentration of water, glucose, salts, oxygen, etc.Physical and psychological distressesDisruptions can be mild to severeIf homeostasis is not maintained, death may resultHomeostas

21、is is disrupted by ANY change in the environment! Biocybernetics （生物控制論）is the application of cybernetics to the biological science.Cybernetics has close connections to biology and medicineDefinition by Norbert Wiener: Cybernetics （控制論） is the science of communication and control in machines and liv

22、ing organisms.Control needs communication to obtain signalsControl is based on the transmission of information.How to keep Homeostasis ? Control systems of the body體內(nèi)的控制系統(tǒng)Control system in the body Feedback control system：Negative feedback system； Positive feedback system Feed-forward control system

23、生理功能的反饋控制系統(tǒng)和前饋控制系統(tǒng)示意圖Negative Feedback Control of RoomTemperatureNegative Feedback-promotes stability :Positive Feedback正反饋Figure 1.6In positive feedback systems, the output enhances or exaggerates the original stimulus正反饋沒有糾偏的效果，一般對(duì)穩(wěn)態(tài)的維持不發(fā)揮作用。病理情況下的正反饋心衰 心臟收縮力低下 射血無力 心室博出量減少 心室殘留血量增多 心室擴(kuò)大、耗氧量增多 心臟負(fù)擔(dān)加重、收縮力進(jìn)一步減弱 更嚴(yán)重的心衰負(fù)反饋與正反饋的比較比較項(xiàng)負(fù)反饋正反饋反饋信息方向與控制信息相反與控制信息相同對(duì)控制系統(tǒng)的作用制約、抑制、減弱其活動(dòng)再生、促進(jìn)、加強(qiáng)其活動(dòng)作用效果減小偏差信息減弱控制信息減小輸出變量增大偏差信息增強(qiáng)控制信息加大輸出變量輸出與輸入關(guān)系輸出制約輸入輸出強(qiáng)化輸入Feed-forward controllers require learning from experienceFeed-forw