Diseases and Disease Related Organisms Diane Young, Instructor From The Human Body in Health and Disease Text

Disease What is it? Abnormal state in which part or all of the body is not properly adjusted or is not capable of carrying on all of its required functions.

Causes of Disease Direct Causes: Disease-producing organisms Malnutrition Physical agents Chemicals Birth defects Degenerative processes Neoplasms

Causes Cont’d Predisposing Causes Age Sex Heredity Living conditions and habits Occupations Physical exposure Preexisting illness Psychogenic influences

Study of Disease Pathophysiology- the study of the physiologic basis of disease Includes studying both the pathologic and physiological aspects and the need to understand the fundamentals of each in treating any body disorder.

Terminology Etiology – the study of the cause or origin of a disease

Terminology Cont’d Diseases are on the basis of severity and duration: Acute – relatively severe but usually last a sort time Chronic – often less severe but likely to be continuous or recurring for long periods of time. Subacute – intermediate between acute and chronic, not as severe as acute nor as long lasting as chronic disorders.

Terminology Cont’d Idiopathic – means “self-originating” or “without known cause” Communicable – one that can be transmitted from one person to another Epidemic- Occurrence of a disease among many people in a given region at the same time Endemic – a disease that is found to a lesser extent but continuously in a particular region.

Terminology Cont’d Diagnosis – Identification of an illness Symptoms – evidence of disease as noted by the patient Signs – objective manifestations the doctor or other health care professionals can observe. Syndrome – a characteristic group of symptoms and signs accompanying a given disease Prognosis – a prediction of the probable outcome of a disease based on the condition of the patient and the physician’s knowledge about the disease.

Terminology Cont’d Therapy – course of treatment for a particular disease Prevention – methods used to stop a disease from occuring

Modes of Infection Microorganisms – microscopic organism Microbe & germ – other terms for microorganism Parasite – any organism that lives on or within another (host). Parasitology – study of parasites Pathogen – any disease causing organism Infection – adverse effects caused by invading pathogens Local infection – restricted to a relatively small area Systemic infection – affects the whole body

Modes of Transmission Other humans Direct contact Indirect contact Insects Deposit infectious material on food, skin or clothing bites Animals Feces Bites Deposit infectious material on food, skin or clothing

Microbiology The study of microorganisms Specializations Bacteriology Mycology Virology Protozoology

Bacteria Rod-shaped cells (bacilli) - Tetanus, diphtheria, tuberculosis, typhoid fever Spherical cells (cocci) – strep, staph, diplococci (gonorrhea, meningitis) Curved rods – (vibrio, spirillum, spirochetes) – syphilis (spirochete). Rickettsias and chlamydias – typhus and Rocky Mountain spotted fever

Fungi A large group of simple plantlike organisms Yeasts – single-celled form of fungi Molds-fuzzy, filamentous form of fungi Examples are: mushrooms, puffballs, bread molds, and the yeasts used in baking and brewing.

Fungi cont’d Disease – mycotic (fungal) Athletes foot, ringworm Candida – thrush, vaginitis Pnuemonia can be caused by inhalation of fungal spores contained in dust particles

Viruses Small microorganism that can reproduce only within a living cell No universal classification for viruses Examples: Measles, polio-myelitis, hepatitis, chickenpox, common cold, AIDS. THESE DO NOT RESPOND TO ANTIBIOTICS

Protozoa Animal-like organisms Amebas Ciliates Flagellates Sporozoa

Parasitic Worms Roundworms Intestinal roundworms Pinworms Hookworms Others Trichina – found in pork – causes trichinosis Filariasis – transmitted by insect bites – found in tropical and subtropical lands

Parasitic Worms Cont’d Flatworms Spread by infected, improperly cooked meats (beef, pork, fish) Can invade the blood, lungs, liver and intestine

Microbial Control Sewage and garbage disposal Purification of water supply Prevention of food contamination Milk pasteurization Aseptic Methods Sterilization Disinfection (bactericide and germicide) Antisepsis

Drugs Chemotherapy – treatment of disease by the administration of a chemical agent Antibiotics – chemical substance produced by living cells Can kill or arrest the growth of pathogenic microorganisms by upsetting vital chemical processes within them. Resistant strains of pathogens – certain strep, staph and bacilli