Diseases

INTRODUCTION TO DISEASES Chapter 17.1

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.

THE BODY’S DEFENSES AGAINST INFECTION Chapter 17.2

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

NON-COMMUNICABLE DISEASES Chapter 17.3

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