Conspectus留英疾病浅论

1、1会计学Conspectus留英疾病浅论留英疾病浅论 Sub-health: It is a situation in which the person does not show specific symptoms and signs of disease, but lives a low-quality of life both physical1y and mentally causes homeostasis is disturbed disturbances of function, metabolism and structure pathological changes or a

2、bnormal life process symptoms and signs lEtiology is the study of the causes of diseases or pathologies. Biological agents: are the cause of infectious diseases. Biological agents are usually referred as microorganisms and parasites, such as bacteria, virus, fungi, rickettsia, spirochete, etc. Chemi

3、cal agents: corrosive chemicals: such as strong acids and alkalis ( HCl, H2SO4, NaOH, etc. ) other chemicals: binding of carbon monoxide to hemoglobin Physical agents: mechanical forces: trauma bone fracture extremes of temperature: T contact dermatitis or heat stroke; T frostelectrical injuries:ext

4、ensive tissue injury radiation: directly hitting the target molecules Different from chemical or biologic agents, most of the physical factors only participate in the initiation but not in the development of the disease. (nonspecific) Nutritional imbalance:nutrients excesses: high lipids and carbohy

5、drates diet obese disease heart disease(hypertension) diabetesnutrients deficiencies:The most common nutritional deficiency is the lack in certain constituents, such as vitamins, calcium, and trace elements. iron deficiency anemia: beriberi: lack of vitamin B Genetic factors: Genetic derangements ma

6、y fall into chromosomal disorders, including numerical and structural abnormalities, single or polygenic mutations. Downs syndrome hemophilia (blood coagulation factor VIII) Sickle cell anemia Sickle cell anemia: Sickle cell anemia results from a defect in the chain of the hemoglobin molecule. Conge

7、nital factors:Abnormal embryonic developmental error resulting from maternal infections, diet and drug-taking during pregnancy. lAlcohol: fetal alcohol syndrome ( FAS ) Immunological factors: The immune response is deficient or inappropriately strong or misdirected.immunodeficiency disease: AIDSalle

8、rgy or hypersensitivity : Sea foods, cows milk, egg Penicillin autoimmune disease: rheumatoid arthritis systemic lupus erythematosus(SLE)Psychological factors: Anxiety, strong or persistent psychological stimulation or stress may lead to mental illness and may be related to some diseases，such as hyp

9、ertension，peptic ulcer，coronary heart disease，and depression Precipitating Factors: Precipitating Factors:lBody condition: a high serum cholesterol level and hypertension: a person may be predisposed to myocardial infarctionlSocial condition: General Rules Fundamental Mechanisms Alteration of Cause

10、and Effect Correlation Between Systemic and Local Regulation Disruption of Homeostasis Process of Damage and Anti-damage The term of homeostasis denotes the process whereby the internal environment of an organism tends to remain balanced and stable，which is required for optimum functioningDisruption

11、 of homeostasis by harmful agents may cause diseases. Disruption of Homeostasis Damages are usually made when a variety of harmful insults attack the body. During this process, anti-damage responses are also induced in the body to restore the normal situation. The onset and development of a disease

12、depend on the strength of damage and anti-damage factors. It is to emphasize that there is no critical borderline between damage and anti-damage processes and overdo of anti-damage process will cause new injury to the body Process of Damage and Anti-damage The bone marrow produces more erythrocytes

13、to provide relatively sufficient oxygen to the tissue during the process of chronic hypoxia. However, the overproduction of red blood cell ( the consequence of chronic hypoxia ) now becomes the cause of polycythemia, in which the blood viscosity is high and thus thrombus may be formed in vessels Alt

14、eration of Cause and Effect Diseases are generally systemic whereas the local pathological alterations are recognized to be representatives of systemic diseases. Local alterations can affect the whole body through neural and humoral regulation, and the systemic functional status can in turn affect t

15、he development of local damages via the same regulating system. General rules for pathogenesis of diseases: Correlation Between Systemic and Local Regulation A severe furuncle ( folliculitis ) will not only cause inflammation, such as congestion and edema, at the site, but also lead to systemic reac

16、tions of fever and elevated leukocytes. Correlation Between Systemic and Local Regulation The same furuncle may represent a severe systemic metabolic disorder caused by diabetes mellitus, and at this situation, the furuncle could only be cured by proper control of diabetes Fundamental mechanisms for

17、 diseases: Cellular Mechanism Molecular Mechanism Neural Mechanism Humoral Mechanism Fundamental mechanisms for diseases: Neural Mechanism damage neural system directly(virus, type B encephalitis) through neural reflex We can explain one of the mechanisms of with neural mechanism. continuous nervous

18、 tension, anxiety, worry or pressure sympathetic N.(+) vasoconstriction BP ( hypertension) Humoral dysfunction generally indicates the alterations in number and in activities of some humoral factors. endocrine, paracrine, autocrine， intracrine Humoral Mechanism Fundamental mechanisms for diseases: h

19、ormones: thyroxin stimulating hormone(TSH), sex hormones chemical mediators: histamine, prostaglandins cytokines: interleukins, tumor necrosis factors(TNF), interferons Humoral Mechanism Fundamental mechanisms for diseases: During the development of diseases，the regulations in humoral and neural sys

20、tem are usually simultaneous. is a result of multifactorial effects. Some of the pathogens can destroy the cells with no selection, such as strong acid and alkali. Others attack cells selectively, such as hepatitis virus damages specifically the hepatocytes. The selective damage of the cells mainly

21、involves cell membranes ( receptors ) and different types of organelles，such as mitochondria Fundamental mechanisms for diseases: Cellular Mechanism When a pathogen induces an illness, it always involves alterations of different types of molecules, such as cytoskeleton proteins ( structural proteins

22、), enzymes, receptors, pumps, channels ( functional proteins ), and so on. These alterations may be caused by gene mutations or post translational modifications. The diseases caused by these macromolecules are generally termed Fundamental mechanisms for diseases: Molecular Mechanism This is the best

23、 outcome of a disease. In this case, the pathologically altered metabolism, structure and function are perfectly restored, and the symptoms and signs of the disease disappear entirely. The main symptoms disappear but some pathological changes are left behind, namely sequela. Sequela is generally bro

24、ught about by the compensatory response to maintain a relatively normal activity. after some heart disease cardiac ventricular hypertrophy because of long term pressure-overloadafter rheumatic fever heart valve damageafter burn formation of scar Traditionally, the cessation of heart beats was used a

25、s criterion of death of a body. The accepted definition of death is . Brain death is a state of prolonged irreversible and permanent disappearance of cerebral functions. Criteria of brain death: (1) Cessation of spontaneous respiration: The cessation of spontaneous respiration is considered as most

26、cardinal manifestation of brain death. (2) Irreversible coma: A state of unresponsive coma, represented by complete lack of cerebral response to any form of external excitations. (3) Absence of cephalic reflexes: It includes the absence of papillary reflex, corneal reflex, cough reflex and swallow reflex. Criteria of brain death: (4) Dilated pupils (5) Absence of any electric activity of the brain: Flat electroencephalograph ( EEG ) may appear even under strong stimulation. (6) Confirming test indicating absence of cerebral circulation Sub-health: It is a situation in which the person does