Introduction to Pathophysiology PDF

Introduction to Pathophysiology Dr. kefah Zaben kefah zaben  Introduction to Pathophysiology The word ‘Pathology’ is came from two Greek words --- Pathos meaning suffering, and ---- logos meaning study. Pathology is scientific study of structure and func...

Introduction to Pathophysiology Dr. kefah Zaben kefah zaben  Introduction to Pathophysiology The word ‘Pathology’ is came from two Greek words --- Pathos meaning suffering, and ---- logos meaning study. Pathology is scientific study of structure and function of the body in disease. kefah zaben  Introduction to Pathophysiology In other words, Pathology involves of the abnormalities that occur in normal anatomy (including histology) and physiology owing to disease. kefah zaben  Pathophysiology The term pathophysiology, may be defined as the physiology of altered (changed ) health. The term combines the words pathology and physiology. Pathology (from the Greek pathos, meaning “disease”) deals with the study of the structural and functional changes in cells, tissues, and organs of the body that cause or are caused by disease. Physiology deals with the functions of the human body. kefah zaben  Pathophysiology Pathophysiology deals not only with the cellular and organ changes that occur with disease, but with the effects that these changes have on total body function. Pathophysiology focuses on the mechanisms of the underlying disease and provides the background for preventive as well as therapeutic health care measures and practices. kefah zaben  Introduction to Pathophysiology ‘Pathophysiology’ encompassed by two words: --- Patho = suffering ; -- physiology= study of normal function. Pathophysiology includes study of disordered function or breakdown of homeostasis in diseases. Pathologists : a person who diagnostic of the disease. kefah zaben  Introduction to Pathophysiology Therefore, knowledge and understanding of pathology is essential for all would-be doctors, general medical practitioners and specialists since unless they know the causes, mechanisms, nature and type of disease, and understand the language spoken by the pathologist in the form of laboratory reports, they would not be able to establish appropriate treatment or suggest preventive measures to the patient. kefah zaben  Introduction to Pathophysiology For the student of any system of medicine, The discipline of pathology forms a vital bridge between initial learning phase of preclinical sciences and the final phase of clinical subject. kefah zaben  Health and disease Before there were humans on earth, there was disease, Since pathology is the study of disease, then what is disease? In simple language, disease is opposite of health i.e. what is not healthy is disease. kefah zaben  Health and disease Health defined as a condition when the individual is in a complete accord with the surroundings. while disease is loss of comfort to the body (i.e. dis-ease). However, it must be stood that in health there is a wide range of ‘normality’ e.g. in height, weight, blood and tissue chemical composition etc. kefah zaben  Disease Disease defined as an interruption, cessation, or disorder of a body system or organ structure that is characterized usually by a recognized etiologic agent or agents, an identifiable group of signs and symptoms, or consistent anatomic alterations. kefah zaben  Disease Disease can be defined as any deviation from the normal structure or function of any part, organ, or system of the body that is manifested by a characteristic set of symptoms or signs and whose etiology, pathology, and prognosis may be known or unknown. kefah zaben  Health and disease Disease also needs to be appreciated that at cellular level, the cells display wide range of activities within the broad area of health similar to what is seen in diseased cells. Therefore, health and disease are not absolute but are considered as relative states. kefah zaben  Health and disease A term commonly confused with disease is illness. disease suggests an thing with a cause. illness is the reaction of the individual to disease in the form of symptoms (complaints of the patient) and physical signs (elicited by the physician). kefah zaben  Disease vs. Illness. Disease usually causes illness, however one can have a disease without illness. For example, Cardiac disease has been called the silent killer because you can have it without knowing it. If you do not know you have it, there will be no effects of illness, but you might die of the disease. Also, one can have an illness without having a diagnosed disease. For example, Chronic pain, often occurs when a person has pain but there is no diagnosable structural damage. kefah zaben  Health and disease However disease and illness are not separate, The study of diseases is done in pathology while the learning and management of illnesses is done in wards and clinics. In addition to disease and illness, there are syndromes (meaning running together) characterized by combination of symptoms caused by altered physiologic processes. kefah zaben  Health and disease Disease: loss of homeostasis, or when physical or mental capacities cannot be fully utilized (interruption, cessation or disorder in the function of an organ or system). Disease is referred as abnormal manifestation of deregulated homeostasis caused by harmful agents. kefah zaben  Health and disease The development of a disease is definitely a pathologic process with a characteristic set of signs and symptoms involved in the whole body or any of its parts. Health is a complete state of physical, mental, and social well being and not merely the absence of diseases or infirmity (WHO, 1978). kefah zaben  Terminology in Pathology It is important for a beginner in pathology to be familiar with the language used in pathology: Patient is the person affected by disease. Lesions are the characteristic changes in tissues and cells produced by disease in an individual. Pathologic changes or morphology consist of examination of diseased tissues. Pathologic changes can be recognized with the naked eye (gross or macroscopic changes) or studied by microscopic examination of tissues. kefah zaben  Terminology in Pathology Causal factors responsible for the lesions are included in etiology of disease (i.e. ‘why’ of disease). Mechanism by which the lesions are produced is termed pathogenesis of disease (i.e. ‘how’ of disease). Functional implications of the lesion felt by the patient are symptoms. and those discovered by the clinician are the physical signs. kefah zaben  Terminology in Pathology Clinical significance of the morphologic and functional changes together with results of other investigations help to arrive at an answer to what is wrong (diagnosis), what is going to happen (prognosis), what can be done about it (treatment), and finally what should be done to avoid complications and spread (prevention) (i.e. ‘what’ of disease). kefah zaben  Terminology in Pathology Pathology : focus on physical changes in diseased organs and tissues Pathology emphasizes the structural changes Pathophysiology : abnormal functioning of diseased organs and how it applies to medical treatment and patient care Pathophysiology : focuses on the functional and metabolic alterations and the mechanisms Also named: Physiopathology ,Physiology of Disease , Physiology of Disordered Function kefah zaben  Why is Pathophysiology Important? Pathophysiology play a role as a bridge between different basic sciences, not only between the basic science and diseases. Pathophysiology ; Enabling the students, physicians and other medical practitioner to understand why and how diseases develop and various clinical manifestations appear, and what are the fundamental kefah zaben mechanisms.  Terminology in Pathology Etiology : is study the causative agents including microorganisms, environmental, social factors and personal habits as contributing factors that causes disease. When the etiology is unknown, the disease is called idiopathic. kefah zaben  Etiological factors Extrinsic Factors Biological agents Chemical agents Physical agents Nutritional imbalance kefah zaben  Etiological factors Intrinsic Factors Genetic factors Congenital factors Immunological factors Psychological factors kefah zaben  Categories of etiology Genetic disease: genes are responsible for a structural or functional defect Congenital disease: genetic information is intact, but the intrauterine environment interferes with normal development Acquired disease: disease is caused by factors encountered after birth (biological agents, physical forces, and chemical agents) kefah zaben  Etiological factors Predisposing factors Genetic constitution Physiological diathesis (Stress) Psychological characteristics kefah zaben  Etiological factors Precipitating Factors Natural conditions Physical condition Social condition kefah zaben  Terminology in Pathology Clinical manifestations: indications that the person is sick Symptoms: unobservable effects of a disease reported by the patient Signs: observable or measurable traits Syndrome: a characteristic combination of signs and symptoms associated with a specific disease. kefah zaben  Terminology in Pathology Pathogenesis: sequence of events in the of development of a disease Disruption of homeostasis Process of damage and anti-damage Reversal role of cause and result Correlation between systemic and local regulations kefah zaben  Terminology in Pathology Sequelae : lesions or impairments resulting from a disease Acute conditions : rapid onset, develop quickly, usually of short duration Chronic conditions : longer duration onset may be sudden or insidious (proceeding in a gradual) kefah zaben  Terminology in Pathology Distribution of lesions may be: Local – confined to one area of the body Systemic – widely distributed throughout the body Within an organ damage can be: Focal if there are only one or more distinct sites of damage Diffuse if the damage is uniformly distributed kefah zaben  Terminology in Pathology Diagnosis : identification of the specific disease Therapy : the treatment of the disease to either effect a cure or reduce the patient’s signs and symptoms Prognosis : prediction of a disease’s outcome kefah zaben