Pathophysiology_correct.ppt

Basic Concepts of Disease Processes Introduction to Pathophysiology Learning objectives  The student will be able to describe current issues arising from pathophysiology, such as ethical dilemmas,  The student will be able to describe normal structure and function of cells.  The student will unde...

Basic Concepts of Disease Processes Introduction to Pathophysiology Learning objectives  The student will be able to describe current issues arising from pathophysiology, such as ethical dilemmas,  The student will be able to describe normal structure and function of cells.  The student will understand how cells adapt to changes in their environment.  Explore aspects of cell injury and cell death that are important in many pathophysiological conditions.  the student will learn how the structure of DNA enables it to transmit genetic information.  Student will be able to explain the types of genetic disorders and learn how they are inherited. PATHOPHYSIOLOGY It builds on what you learned in Anatomy and Physiology It focuses on the functional physiologic changes that happens to the body’s organs and tissues as the disease progresses. Compares cause and effect of disease (how does disease affect body function) HOMEOSTASIS This is a state of balance among all body systems is crucial for the body's survival and proper functioning. Example: Body temperature control in humans is one of the most familiar examples of homeostasis. Normal body temperature hovers around 37 °C (98.6 °F), but several factors can affect this value. E.g.: Disease process QUESTIONS ASKED IN PATHOPHYSIOLOGY 1. What is the cause of disease? 2. What are the mechanisms responsible for disease onset, progression and recovery? 3. What are the mechanisms responsible for the development of signs and symptoms of disease EXAMPLE OF PATHOPHYSIOLOGY 1. Asthma is a condition caused by bronchial inflammation, causing temporary airway narrowing and increased sensitivity 2. Chronic inflammation causes damage to the lung tissue, excessive mucous production, and intermittent airway obstruction. 3. Patients may experience chest pain, cough, dyspnea, wheezing, rapid breathing, mucus expulsion, tachycardia, pulsus paradoxus, and hypoxia. EXAMPLE OF PATHOPHYSIOLOGY Student Activity: Determine Pathophysiology for the following disease using the algorithm provided Hypertension Breast Cancer Diabetes Hypothyroidism Hepatitis B WHAT IS HEALTH AND DISEASE Health Physical, mental, and social well-being Disease Deviation from the normal state of homeostasis HEALTH INDICATORS Health indicators are quantifiable characteristics used by researchers to describe population health, guide healthcare policy, and predict disease burdens, enabling prediction of health status, individual risk, and prognosis. Examples of health indicators include Activity levels Students should give other examples PATHOPHYSIOLOGY AND CLINICAL TRIALS Pathophysiology and clinical trials are related in that researchers should justify why a treatment should be tested again if it has already been tested in a representative population and failed to show efficacy. This prevents redundant research which can be harmful and wasteful. Phases of Drug Trials Phase I:  Drug is tested on a small group of people to determine best dose, timing, treatment delivery method, and side effects. Phase II:  The drug is tested in larger groups to assess effectiveness and safety.  Some trials are case series or randomized controlled trials. Phase III:  It’s tested on a larger group (1,000–3,000) to confirm effectiveness, monitor side effects, and compare with standard treatments. Phase IV:  Post marketing surveillance trials post-license, aiming to understand side effects, long-term risks, benefits, and effectiveness when used widely. LANGUAGE OF PATHOPHYSIOLOGY LANGUAGE OF PATHOPHYSIOLOGY Gross level Examination  Gross examination, also known as gross pathology, is a macroscopic diagnostic tool used in pathology, able to accurately diagnose up to 90% of specimens.  Compares normal tissue vs diseased tissue Microscopic level Examination  Also known as histology.  It is the microscopic examination of living tissue at a cellular level, studying its structure, form, and function under a microscope, also known as microscopic anatomy and histochemistry. GROSS EXAMINATION LANGUAGE OF PATHOPHYSIOLOGY Biopsy  A biopsy is a surgical procedure that involves removing a tissue sample and examining it under a microscope. It is the gold standard in diagnosing cancer Autopsy  Examination of the body and organs after death to determine cause of death. Done by a medical examiner LANGUAGE OF PATHOPHYSIOLOGY (CONT’D) Diagnosis Identification of a specific disease. Etiology Causative factors in a particular disease Predisposing factors Tendencies that promote disease development Pathogenesis Development of the disease LANGUAGE OF PATHOPHYSIOLOGY (CONT’D) Acute disease Develops quickly, marked signs, short term Chronic disease Often milder, develops gradually, persist for long time Subclinical state Pathologic changes occur, no obvious manifestations Latent state No symptoms or clinical signs are evident MEDICAL HISTORY Current and prior illnesses Allergies, Hospitalizations and treatment Specific difficulties Any type of therapy or drugs Prescription Non-prescription Herbal items including food supplements Why is obtaining health history important? LANGUAGE OF PATHOPHYSIOLOGY (CONT’D) Prodromal period Early development of a disease Signs are non-specific or absent Manifestations Signs and symptoms of disease Syndrome Collection of sign and symptoms Often affecting more than one organ Language of Pathophysiology (Cont’d) Sequelae Unwanted outcomes of primary condition Convalescence Period of recovery Prognosis Probability for recovery or for other outcomes Rehabilitation Maximizing function of diseased tissues Language of Pathophysiology (Cont’d) Remissions Manifestations of the disease subside or are absent Precipitating factor Condition that triggers an acute episode Complications New secondary or additional problems Therapy Treatment measures to promote recovery or slow the progress of a disease Language of Pathophysiology (Cont’d) Epidemiology Science of identifying the causative factors and tracking the pattern or occurrence of disease Morbidity Indicates the number of people with a disease within a group Mortality Indicate the number of deaths resulting from a particular disease within a group LANGUAGE OF PATHOPHYSIOLOGY Occurrence of disease Tracked by incidence and prevalence. Incidence Number of new cases in each population within a specified time. Prevalence Number of new and old or existing cases in a specific population and within a specified time. THE OCCURRENCE OF DISEASE Language of Pathophysiology (Cont’d) Epidemics Occur when a higher-than-expected number of cases of an infectious disease occur with a given area Pandemics Involves a higher number of cases in many regions of the globe Can you give examples of each? CELLULAR CHANGES THAT HAPPEN IN PATHOPHYSIOLOGY CELLULAR ADAPTATIONS Atrophy Decrease in the size of cells, results in reduced tissue mass Hypertrophy Increase in cell size, results in enlarged tissue mass Hyperplasia Increased number of cells, resulting in an enlarged tissue mass CELLULAR ADAPTATIONS Metaplasia Mature cell type is replaced by a different mature cell type Dysplasia Cells vary in size and shape within a tissue Anaplasia Undifferentiated cells with variable nuclear and cell structures Neoplasm “New growth” – commonly called tumor ABNORMAL CELL GROWTH PATTERNS CELL DAMAGE Ischemia Deficit of oxygen in the cells Hypoxia Reduced oxygen in tissues Give examples of disease that may result in this type of cell damage CELL DAMAGE (CONT’D) Physical damage Excessive heat or cold Radiation exposure Mechanical damage Pressure or tearing of tissue Chemical toxins Exogenous: from environment Endogenous: from inside the body CELL DAMAGE (CONT’D) Microorganisms i.e., bacteria and viruses Abnormal metabolites Genetic disorders Inborn errors of metabolism Altered metabolism Nutritional deficits Imbalance of fluids or electrolytes TISSUE NECROSIS Infarction An area of dead cells because of oxygen deprivation Gangrene An area of necrotic tissue that has been invaded by bacteria DRY GANGRENE OF THE TOE TYPES OF TISSUE NECROSIS Liquefaction necrosis Dead cells liquefy due to release of cell enzymes Coagulative necrosis Cell proteins are altered or denatured – coagulation Fat necrosis Fatty tissue is broken down into fatty acids Caseous necrosis Form of coagulation necrosis Thick, yellowish “cheesy” substance forms TISSUE NECROSIS COAGULATIVE NECROSIS OF THE KIDNEY LIQUEFACTION NECROSIS IN THE BRAIN FAT NECROSIS IN THE MESENTERY