Transcript Diseases
Diseases Chapter 17.1 INTRODUCTION TO DISEASES Disease • 2 Types – Communicable Disease – a disease that can be passed to a person from another person, animal, or object. – Non-Communicable Disease – a disease that is not transmitted by pathogens. Causes of Communicable Diseases • Pathogens – tiny organisms that cause communicable diseases. • Infections – a condition that occurs when pathogens enter the body, multiply, and damage cells. • Bacteria – tiny one-celled organisms that live nearly everywhere. • Virus – the smallest disease-causing organism. Other types of Pathogens • Fungi – primitive life-forms that feed on organic materials. • Protozoa – Single-celled organisms that re usually harmless but that can cause certain diseases. • Rickettsias – disease-causing organisms that resemble bacteria but multiply like viruses. How are Pathogens Spread? • Direct contact with the infected person. • Indirect contact with an infected person. • Contact with a vector. – A vector is an organism, such as an insect, that transmits a pathogen. Chapter 17.2 THE BODY’S DEFENSES AGAINST INFECTION In Immune System • Considered the main line of defense • Nonspecific response – This is a general response such as inflammation or increased blood flow to the specific area. • Specific response – This is specific more specialized response. – This would be antibodies that help you resist specific disease such as smallpox. The Lymphatic System • A secondary circulatory system that helps the body fight pathogens and maintain its fluid balance. • Produces lymphocytes – B-Cells – T-Cells Immunity • 2 Types – Natural Immunity is present at birth. • Are present on your skin and in mucous membranes. – Acquired Immunity develops over a person’s lifetime. • Sometimes acquired through a vaccine. • A Vaccine is a preparation of dead or weakened pathogens that is injected into the body to cause the immune system to produce antibodies. Typical Vaccinations Chapter 17.3 NON-COMMUNICABLE DISEASES What are Non-Communicable Diseases • Diseases that are not transmitted by pathogens. • Chronic Diseases – Diseases that are present either continuously or off and on over a long time. • Degenerative Diseases – Diseases that cause further breakdown in the body cells, tissues, and organs as they progress. Common Non-Communicable Diseases • • • • • • • • Allergies Alzheimer’s disease Arthritis Asthma Cancer Cardiovascular disease Cerebral palsy Cystic fibrosis