Introduction to Pathophysiology for BScN

introduction to the pathophysiology for nursing studentds

1. UNIT I: INTRODUCTION TO PATHOPHYSIOLOGY Asma Rafaqat

2. Objectives Define Health, Pathology & Pathophysiology Differentiate among Pathophysiology and other biomedical sciences Discuss the Basic concepts of disease and its development. Briefly discuss each of the five components of the disease process: Prevalence Aetiology Pathogenesis Clinical manifestation Outcomes

3. Health & Pathology Health: The World Health Organization (WHO) in 1948 defined health as a “state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity.” Pathology has been derived from the Greek word “pathos” meaning “disease ”. Pathology 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.

4. Pathophysiology The term pathophysiology , may be defined as the physiology of altered health. The term combines the words pathology and physiology . Physiology deals with the functions of the human body. Thus, “ Pathophysiology deals with the cellular and organ changes that occur with disease and with the effects that these changes have on total body function”.

5. Old Concepts of Disease In prehistoric times, people believed that angry gods or evil spirits caused ill health and disease . To cure the sick , the gods had to be pacified or the evil spirits driven from the body . In time, this task became the job of the healers , or tribal priests .

6. They tried to pacify the gods or drive out the evil spirits using magic charms, spells, and incantations. There also is evidence of surgical treatment. They cut a hole in the skull of the sick person. It is believed that this was done to release spirits responsible for illness. Prehistoric healers probably also discovered that many plants can be used as drugs.

7. Old Concepts of Disease Conti….. Even though science and technology have advanced the understanding and treatment of disease, misconceptions and fantasies about disease still arise. In previous centuries, diseases such as leprosy, plague, and tuberculosis were fodder for taboos and mythologies; today, it is cancer and AIDS . Hippocrates (460–377 BC) believed that disease occurred when the four humors —blood from the heart, yellow bile from the liver, black bile from the spleen, and phlegm from the brain—became out of balance . Hippocrates is identified with an approach to health that dictated plenty of healthy exercise , rest in illness, and a moderate, sober diet.

8. Disease Disease has been defined as “any deviation from or interruption of the normal structure or function of a part, organ, or system of the body that is manifested by a characteristic set of symptoms or signs ”. E.g. if the heart fails to pump blood to the cells and tissues or the gallbladder develop stones.

9. Disease Development Host Environment Agent The Epidemiologic Triad of A Disease. Gordis: Epidemiology, 4th ed . 2008

10. Disease Development Disease develops by an interaction of the An infectious or other type of agent , Human host , and The environment that promotes the exposure. Agent is an element or substance, animate or inanimate the presence or absence of which may initiate or perpetuate a disease process. For such an interaction to take place, the host must be susceptible . Any organism capable of supporting the nutritional and physical growth requirements of another is called a host.

11. Factors That May Be Associated with Increased Risk of Human Disease Host Characteristics Types of Agents and Examples Environmental Factors Age Biologic Bacteria, Viruses Temperature Sex Humidity Race Chemical Poison, Alcohol, Smoke Altitude Religion Crowding Customs Physical Trauma, Radiation, Fire Housing Occupation Neighbourhood Genetic Profile Nutritional Lack, Excess Water Marital Status Milk Family Background Food Previous Disease Radiation Immune Status Air Pollution

12. Prevalence Prevalence is the number of people in a population who have a particular disease at a given point in time or period . It is determined by dividing the existing number of cases by the population at risk for development of the disorder during the same period .

13. Aetiology The causes of disease are known as etiologic factors . Among the recognized etiologic agents are biologic agents (e.g., bacteria , viruses ), physical forces (e.g., trauma, burns, radiation ), chemical agents (e.g., poisons, alcohol), and nutritional excesses or deficits . The multiple factors that predispose to a particular disease often are referred to as risk factors .

14. Pathogenesis Pathogenesis is the sequence of cellular and tissue events that take place from the time of initial contact with an etiologic agent until the ultimate expression of a disease .

15. Clinical Manifestation Disease can be manifest in a number of ways . Signs and symptoms are terms used to describe the structural and functional changes that accompany a disease. A symptom is a subjective complaint that is noted by the person with a disorder. S ign is a manifestation that is noted by an observer . Pain, difficulty in breathing , and dizziness are symptoms of a disease . An elevated temperature , a swollen extremity, and changes in pupil size are objective signs that can be observed by someone other than the person with the disease

16. Outcome Outcome is the result of disease process. It may include Recovery Disability or D eath

17. References 1 Gordis , L. (2008). Epidemiology (4th ed.). Philadelphia: Saunders Elsevier . 2 Carol . P. M. (2000) Pathophysiology concepts of altered health states. Philidelphia : J. B. Lippincot .