CHI335 Introduction to Health and Disease PDF

CHI335 Diagnosis I  INTRODUCTION TO T H E H U M A N B O DY A N D D I S EA S E  LEARNING OUTCOMES 1. define anatomy and physiology and explain their interconnectivity 2. Classify the organisation of the body from the chemical level to the organism 3. Identify anatomical terminology for the st...

CHI335 Diagnosis I  INTRODUCTION TO T H E H U M A N B O DY A N D D I S EA S E  LEARNING OUTCOMES 1. define anatomy and physiology and explain their interconnectivity 2. Classify the organisation of the body from the chemical level to the organism 3. Identify anatomical terminology for the study of anatomy and physiology 4. Describe the four types of cellular adaptations and suggest situations when each may occur 5. Identify the major agents of cell injury and explore outcomes 6. Differentiate between the characteristics of reversible and irreversible cell injury 7. Describe the process of cell injury resulting from an ischaemic or hypoxic agent 8. Compare and contrast necrosis and apoptosis 9. Compare and contrast acute and chronic inflammation 10. Explore concepts of health and disease 11. Define the terms pathophysiology, aetiology, pathogenesis, and epidemiology 12. Distinguish between the incidence and the prevalence of a disease STUDY OF THE HUMAN BODY Anatomy Study of body structure Normal position of body structures Physiology Study of the function of body’s organs Anatomy of the body allows it to physiologically function! ANATOMICAL TERMS USED TO DESCRIBE BODY PARTS ORGANISATION OF THE HUMAN BODY Organism (human) Systems Organs Tissues Cells Organelles Molecule Atom ORGANISATION OF THE HUMAN BODY Insert Figure 1-1 CELLS & TISSUES A cell is the basic structural and functional unit of life The human body is composed of trillions of cells Over 250 variations Each type of a cell has a specific function The study of cells is called cytology When cells act together to perform a specific function, the next level of organization is classified as a tissue Four basic types of tissues in the body are epithelial, connective, muscle, and nervous tissue The study of tissues is called histology TYPES OF TISSUES BODY ORGANS AND SYSTEMS Organ Structure formed by organisation of two or more different tissues that work together to carry out specific functions System Organs join to carry out vital functions via a system (next slide) BODY ORGANS AND SYSTEMS For example, the respiratory system consists of the following organs: Nose Nasal cavity Pharynx Larynx Bronchi Lungs SYSTEMS OF THE BODY Insert Figure 1-2 part 1 SYSTEMS OF THE BODY Insert Figure 1-2 part 2 STUDY OF THE HUMAN BODY Homeostasis State of normalcy Relative consistency of the body’s internal environment Disease Changes in the steady state internal environment; Symptoms of a pathological state occurs CELL STIMULATION & INJURY B O DY ’ S R ES P O N S E & O U TCO M E ADAPTATIONS Atrophy A decrease in the size of the cell because of reduced demands Disuse when a person is bedridden for an extended period Hypertrophy An increase in the size of the cell because of increased demands Increase in (work)load on the heart causes cardiac hypertrophy ADAPTATIONS Hyperplasia Increase in number of cells, hypertrophy could also occur Enlargement of the uterus during pregnancy Metaplasia Cells change from one cell type to another Persistent irritation from cigarette smoke changes epithelium ADAPTATIONS Dysplasia Variation in the size and shape of cells within a tissue Breakdown in the organisation and arrangement of the tissue In some tissues, may be precancerous Epithelial cell dysplasia in the cervix of the uterus is considered a potential sign of carcinoma in situ ADAPTATIONS AGENTS OF CELL INJURY Chemical agents Air & environmental pollutants Carbon monoxide, sulphur dioxide, heavy metals, cyanide Agricultural and domestic pesticides, cleaning agents Carbon tetrachloride Drugs used for clinical or recreational purposes MPTP selectively destroys the dopaminergic neurones of the nigrostriatal motor pathway – leading to Parkinson’s disease Free radicals Interactions resulting in reactions with oxygen molecules, forming free radicals – known as highly reactive oxygen species, next slide… CHEMICAL AGENTS AGENTS OF CELL INJURY Physical agents Abrupt or extreme changes in temperature High Temp. → Denaturation of proteins Coagulation within cell Low Temp. → Ice crystal formation Disrupt integrity of membrane Changes in permeability → cell death Mechanics force → Rupture cell membrane → Cell death Electromagnetic radiation → Induce gene mutations → Triggers cancer Radiation → Ionise oxygen molecules → Form free radicals AGENTS OF CELL INJURY Infectious agents Bacteria Viruses Parasites AGENTS OF CELL INJURY Nutritional agents Nutrient deficiency (e.g. Macronutrient, Vitamins and minerals) Inadequate intake Disrupted absorption Distribution or cellular uptake issues Nutrient excess from Higher intake and poor cellular uptake (e.g. in DM) AGENTS OF CELL INJURY Hypoxaemic and hypoxic (Ischaemic) agents Compromised perfusion → hypoxia or ischaemia (PVD, CVA, MI) Compromised oxygen carrying capacity → hypoxaemia (anaemia) Compromised cellular respiration → hypoxaemia (CO poisoning) O2 →  ATP → change to anaerobic metabolism → Further  ATP →  Lactic acid → Failure of the membrane pumps → Altered Na+, K+, and Ca2+ movement into and out of cell →  Na+ inside cell →  Cellular swelling → Disrupted organelle function and membrane damage → Ca2+ ions released into cytoplasm →  Mitochondrial function →  Intracellular toxicity → Further cell injury ISCHAEMIC INJURY OUTCOMES OF (ACUTE) INJURIES Reversible damage Regeneration A type of healing in which new growth completely restores portions of damaged tissue to their normal state Repair The restoration of tissue architecture and function after an injury Replacement of the damaged tissue with connective tissue cells, fibres and blood vessels, called granulation tissue Granulation tissue will be replaced with functional cells OUTCOMES OF (ACUTE) INJURIES Irreversible damage Fibrosis Severely damaged or non-regenerable tissues are repaired by the laying down of connective tissue, a process commonly referred to as scarring Excessive scar formations in the skin is called keloids OUTCOMES OF (ACUTE) INJURIES Irreversible damage Necrosis Unplanned cell death Destructive changes in a cell’s structure NECROTIC PROCESSES TYPES OF NECROSIS Coagulative Liquefactive Caseous Fat Not Examinable Gangrene Associated with ischaemia APOPTOSIS Programmed cell death – cell ‘suicide’ Integral part of the normal process of tissue maintenance: Cell is no longer required Cell has become redundant as a result of tissue maturation APOPTOSIS NECROSIS VS APOPTOSIS Necrosis Apoptosis 1. Pathological cell death 1. Cell suicide/programmed 2. Numerous cells in tissue 2. One or a few cells in tissue affected affected 3. Cells swell, organelles 3. Cells shrink, organelles disrupted (including nucleus) remain normal, nucleus and and loss of membrane organelles broken down into integrity membrane-bound fragments 4. Induces inflammation 4. No inflammation INFLAMMATION DEFINITION Acute inflammation is a healthy response that serves to protect the body from something damaging and helps in repair Chronic inflammation is the response to a chronic injury or stimulation, and is linked to the tissue damage INFLAMMATION CAUSE Acute inflammation Infections (bacterial, viral, fungal, parasitic) Microbial toxins Tissue necrosis (ischaemia, trauma, physical or chemical injury) Foreign bodies (splinters, dirt, sutures) Immune reactions (i.e. hypersensitivity reactions such as allergy) Chronic inflammation Prolonged exposure to a toxic agent (smoking, silicosis) Persistent injury, infection, or immune reaction (Ulcer, tuberculosis, autoimmune disease (e.g. RA, SLE, AS) INFLAMMATION CLINICAL MANIFESTATION Acute inflammation Lasts a few days Redness (rubor) Heat (calor) Pain (dolor) Swelling (tumor) Loss of function Chronic inflammation Lasts weeks, months, or even years Pain (dolor) Swelling/abnormal tissue formation (tumour) Loss of function CONCEPTS OF DISEASE I N T R O D U C T I O N TO PAT H O P H Y S I O LO GY DISEASE Changes in the steady state internal environment Often used broadly to include Injuries Illnesses Disorders Syndromes DETERMINANTS OF HEALTH AND ILLNESS PATHOPHYSIOLOGY The study of the mechanisms by which disease and illness alter the functioning of the body Related sciences Anatomy Physiology Biology (Bio)Chemistry Microbiology Pathology PATHOPHYSIOLOGY CONCEPT MAP AETIOLOGY The study of the cause or causes of a disease May include diet, environment, genetic factors, occupation, health and age Types Pathogen: disease-causing microorganism Nosocomial: caused by an infection received in a healthcare environment (e.g. hospital) Multifactorial: having more than one cause Iatrogenic: caused by medical treatment Idiopathic: no known cause PATHOGENESIS Origination and development of an illness or disease Encompasses From point at which disease process begins To point when disease presents itself Risk factors (modifiable vs. non-modifiable) Goal of study is to prevent disease or facilitate early diagnosis and intervention CLINICAL MANIFESTATIONS Presenting characteristics of a disease Asymptomatic Signs vs. Symptoms Local vs. Systemic Acute vs. Subacute vs. Chronic Remission vs. Exacerbation (relapse) CLINICAL MANIFESTATIONS Signs Objective findings Evident to someone besides the patient and can be detected through the senses Symptoms Subjective findings Obvious only to the patient DIAGNOSIS AND TREATMENT Diagnosis A label for a disease/pathology Based on diagnostic criteria A combination of a medical history, physical examination, and diagnostic tests/investigations Steps before making a diagnosis Differential diagnosis: list of possible diagnoses ranked in order of probability/priority based on the current information available Tentative/probable diagnosis: a temporary diagnosis Definitive/working diagnosis: a diagnosis of which the physician is almost certain DIAGNOSIS AND TREATMENT Prognosis Likely/expected outcome of a disease Prediction of how one will proceed through the disease process Ranges from excellent with no complications to death Remission, exacerbation, and complications Morbidity vs. mortality Treatment Allopathic approach & Conventional medicine Remedies and medications Complementary and alternative medicine (CAM) Herbal medicines, chiropractic, aromatherapy,… POPULATION HEALTH I N T RO D U C T I O N NOMENCLATURE Epidemiology Incidence vs. prevalence Classification of global disease (find their definitions) Endemic Epidemic Pandemic World Health Organization (WHO) EPIDEMIOLOGY Incidence The number of new cases of a disease/condition diagnosed Within a particular period Usually over a calendar year Prevalence The total number of cases of a disease/condition New and previously diagnosed At a particular time PREVENTION Levels of prevention Primary prevention Prevention of a disease from occurring Secondary prevention Early detection of disease by screening Tertiary prevention Rehabilitation of a patient to prevent complications or progression of disease EVIDENCE-BASED PRACTICE A way of caring for others that is cognisant of the most current research and knowledge in the health professions Characteristics Goes beyond one piece of research Encompasses totality of what is known through research and knowledge and practice of experts Requires conscientious respect for human health variations SELF-DIRECTED STUDY TOPICS Cytoplasm components & their function Cell Transports Types and their characteristics Cell Cycle & their regulation Mitosis & Meiosis Tissue types and their characteristics: Epithelium, Connective, Muscle & Neural (nervous)  REFERENCES 1. Principles of Pathophysiology by Shane Bullock, 2nd Edition 2. Human Diseases by Marianne Neighbors, 5th edition 3. Anatomy, Physiology, and Disease for the Health Professions by Kathryn Booth, 3rd edition 4. Applied Pathophysiology: A Conceptual Approach to the Mechanisms of Disease by Braun & Anderson, 3rd edition