Objectives Define the vocabulary wordsDefine the vocabulary words Define CDC and explain its functionDefine CDC and explain its function Define the patterns of diseaseDefine the patterns of disease List and describe the basic mechanisms of disease and risk factors associated with diseaseList and describe the basic mechanisms of disease and risk factors associated with disease List and describe the five categories of pathogenic organisms and explain how they cause disease (Be able to identify each example on handout)List and describe the five categories of pathogenic organisms and explain how they cause disease (Be able to identify each example on handout)

Know Common Aseptic Methods in Table 5-6 on page 116Know Common Aseptic Methods in Table 5-6 on page 116 Distinguish between the terms benign and malignant as they apply to tumors (Know Table 5-7 on page 118)Distinguish between the terms benign and malignant as they apply to tumors (Know Table 5-7 on page 118) Describe the pathogenesis of cancerDescribe the pathogenesis of cancer Outline the events of the inflammatory response and explain its role in diseaseOutline the events of the inflammatory response and explain its role in disease

Vocabulary Words Health – physical, mental, and social well-being; not merely absence of diseaseHealth – physical, mental, and social well-being; not merely absence of disease Disease – abnormality in body function that threatens healthDisease – abnormality in body function that threatens health Etiology – the study of factors that cause diseaseEtiology – the study of factors that cause disease

More vocabulary words Idiopathic – refers to a disease with an unknown causeIdiopathic – refers to a disease with an unknown cause Signs – objective abnormalities that can be seen or measured by someone other than the patientSigns – objective abnormalities that can be seen or measured by someone other than the patient Symptoms – subjective abnormalities felt only by the patientSymptoms – subjective abnormalities felt only by the patient Syndrome – a collection of different signs and symptomsSyndrome – a collection of different signs and symptoms

Vocabulary (cont’d) Acute – signs and symptoms appear suddenly, persist for a short time, then disappearAcute – signs and symptoms appear suddenly, persist for a short time, then disappear Chronic – develops slowly and lasts for a long timeChronic – develops slowly and lasts for a long time Communicable – can be transferred from one person to anotherCommunicable – can be transferred from one person to another Pathogenesis – the pattern of a disease’s developmentPathogenesis – the pattern of a disease’s development

Incubation – latent or “hidden” stage, no signs of disease are visibleIncubation – latent or “hidden” stage, no signs of disease are visible Convalescence – recoveryConvalescence – recovery Remission – reversal of a chronic disease; when permanent the person is considered “cured”Remission – reversal of a chronic disease; when permanent the person is considered “cured”

CDC Centers for Disease Control and PreventionCenters for Disease Control and Prevention Branch of U.S. Public Health ServiceBranch of U.S. Public Health Service Headquarters in AtlantaHeadquarters in Atlanta Morbidity – disease rates in specific populationsMorbidity – disease rates in specific populations Mortality – number of deaths caused by specific diseasesMortality – number of deaths caused by specific diseases

Patterns of Disease Epidemiology – study of occurrence, distribution, and transmission of diseases in human populationsEpidemiology – study of occurrence, distribution, and transmission of diseases in human populations Endemic – native to a local regionEndemic – native to a local region Epidemic – disease affects many people at the same timeEpidemic – disease affects many people at the same time Pandemic – widespread, perhaps global, epidemicPandemic – widespread, perhaps global, epidemic

Pathophysiology the study of underlying physiological aspects of disease

Mechanisms of Disease Genetic mechanismsGenetic mechanisms Pathogenic organismsPathogenic organisms MalnutritionMalnutrition Tumors and cancerTumors and cancer Physical and chemical agentsPhysical and chemical agents AutoimmunityAutoimmunity InflammationInflammation Degeneration (when tissues break apart)Degeneration (when tissues break apart)

Risk Factors Genetic factorsGenetic factors AgeAge LifestyleLifestyle Stress – psychogenic (mind-caused), ulcers, headaches, hypertensionStress – psychogenic (mind-caused), ulcers, headaches, hypertension Environmental factorsEnvironmental factors Preexisting conditions- example: blisters from a burn break open…..bacterial infectionPreexisting conditions- example: blisters from a burn break open…..bacterial infection

Pathogenic Organisms Viruses invade cells and insert their own genetic code into the host cell’s genetic code causing the cell to produce viral DNA or RNA and protein coatsViruses invade cells and insert their own genetic code into the host cell’s genetic code causing the cell to produce viral DNA or RNA and protein coats Classified by shape, nucleic acid type, and method of reproductionClassified by shape, nucleic acid type, and method of reproduction Know Table 5-1 on page 109Know Table 5-1 on page 109

Viruses

Bacteria secrete toxic substances that damage human tissues, become parasites inside human cells, or may form colonies that disrupt normal human functionBacteria secrete toxic substances that damage human tissues, become parasites inside human cells, or may form colonies that disrupt normal human function Spores - nonreproducing forms of bacteria that resist unfavorable environmental conditionsSpores - nonreproducing forms of bacteria that resist unfavorable environmental conditions

Classifying Bacteria Function: aerobic (require oxygen) vs. anaerobic (no O 2 )Function: aerobic (require oxygen) vs. anaerobic (no O 2 ) Staining properties (composition of cell wall):Staining properties (composition of cell wall): Gram-positive – stained purple by Gram’s staining technique Gram-positive – stained purple by Gram’s staining technique Gram-negative – no staining Gram-negative – no staining Shape and sizeShape and size

Fungi (Fun-jye) Fungi that are pathogenic parasitize tissue on or near the skin or mucous membranes; mycotic infections (often resist treatment)Fungi that are pathogenic parasitize tissue on or near the skin or mucous membranes; mycotic infections (often resist treatment) Protozoa are one-celled organisms that can infest human fluids and cause disease by parasitizing cells or directly destroying themProtozoa are one-celled organisms that can infest human fluids and cause disease by parasitizing cells or directly destroying them

Pathogenic Fungi A Scanning electron micrograph of yeast cells B Infectious mold that forms “fungus balls”

Major Groups of Protozoa Amoebas – pseudopodiaAmoebas – pseudopodia FlagellatesFlagellates CiliatesCiliates Sporozoa (coccidia) – enter cells during one phase of a two part life cycle; borne by vectors (transmitters) during the other phaseSporozoa (coccidia) – enter cells during one phase of a two part life cycle; borne by vectors (transmitters) during the other phase

Pathogenic animals are sometimes called metazoa. Large, multicellular organisms cause disease by parasitizing humans or causing direct injuryPathogenic animals are sometimes called metazoa. Large, multicellular organisms cause disease by parasitizing humans or causing direct injury

Prevention and Control Person-to-person contactPerson-to-person contact Environmental contactEnvironmental contact Opportunistic invasionOpportunistic invasion Transmission by a vectorTransmission by a vector VaccinationVaccination Chemicals – antibiotics (natural compounds derived from living organisms) and synthetic compoundsChemicals – antibiotics (natural compounds derived from living organisms) and synthetic compounds

Tumors and Cancer Neoplasms (tumors) – abnormal growths of cellsNeoplasms (tumors) – abnormal growths of cells Benign – remain localizedBenign – remain localized Malignant – spread, forming secondary tumorsMalignant – spread, forming secondary tumors Metastasis – cells leave a primary tumor and start a secondary tumor at a new locationMetastasis – cells leave a primary tumor and start a secondary tumor at a new location

Classification of Tumors Benign, epithelial tumors:Benign, epithelial tumors: Papilloma – finger-like projectionPapilloma – finger-like projection (wart) (wart) Adenoma – glandular tumorAdenoma – glandular tumor Nevus – small. Pigmented tumorNevus – small. Pigmented tumor (mole) (mole)

Benign, Connective Tissue Tumors:Benign, Connective Tissue Tumors: Lipoma – adipose (fat) tumorLipoma – adipose (fat) tumor Osteoma – bone tumorOsteoma – bone tumor Chondroma – cartilage tumorChondroma – cartilage tumor

Carcinomas Malignant epithelial tissues:Malignant epithelial tissues: Melanoma – involves melanocytes (pigment-producing cells of the skin)Melanoma – involves melanocytes (pigment-producing cells of the skin) Adenocarcinoma – glandular cancerAdenocarcinoma – glandular cancer

Sarcomas Connective tissue cancerConnective tissue cancer Lymphoma – lymphatic cancerLymphoma – lymphatic cancer Osteosarcoma – bone cancerOsteosarcoma – bone cancer Myeloma – bone marrow tumorMyeloma – bone marrow tumor Fibrosarcoma – cancer of fibrous connective tissueFibrosarcoma – cancer of fibrous connective tissue

Causes of Cancer Hyperplasia – growth of too many cellsHyperplasia – growth of too many cells Anaplasia – development of undifferentiated cellsAnaplasia – development of undifferentiated cells GeneticsGenetics CarcinogensCarcinogens AgeAge Injury (radiation)Injury (radiation) VirusesViruses

Pathogenesis of Cancer Early detectionEarly detection Methods of detection:Methods of detection: Self-examination Self-examination Diagnostic imaging Diagnostic imaging (Know pages ) (Know pages ) Grading – assess likely patternGrading – assess likely pattern Cachexia (Ka-Kek-see-ah) – syndrome: appetite loss, weight loss, general weaknessCachexia (Ka-Kek-see-ah) – syndrome: appetite loss, weight loss, general weakness

Causes of death: secondary infections, organ failure, hemorrhage, undeterminedCauses of death: secondary infections, organ failure, hemorrhage, undetermined Treatments: chemotherapy, surgery, radiotherapy, laser therapy, immunotherapy, new strategies (vaccines)Treatments: chemotherapy, surgery, radiotherapy, laser therapy, immunotherapy, new strategies (vaccines)

Inflammation Response reduces injury to tissues, homeostasisResponse reduces injury to tissues, homeostasis Signs- redness, swelling, heat, painSigns- redness, swelling, heat, pain Inflammation mediators released from tissues– histamine, prostaglandins, kininsInflammation mediators released from tissues– histamine, prostaglandins, kinins

Inflammation Mediators Some cause blood vessels to dilate (widen), increasing blood volume (redness,heat); white blood cells travel quickly to siteSome cause blood vessels to dilate (widen), increasing blood volume (redness,heat); white blood cells travel quickly to site

Some increase blood vessel permeability (swelling (edema) and pain); white blood cells move easily out of vessels, irritant is diluted, and exudate (fluid in inflamed tissue)accumulatesSome increase blood vessel permeability (swelling (edema) and pain); white blood cells move easily out of vessels, irritant is diluted, and exudate (fluid in inflamed tissue)accumulates

Some attract white blood cells to the site - chemotaxisSome attract white blood cells to the site - chemotaxis PhagocytosisPhagocytosis Pus – exudate becomes thick with white blood cells, dead tissue and bacterial cellsPus – exudate becomes thick with white blood cells, dead tissue and bacterial cells

Inflammatory Diseases Local or systemic (body-wide)Local or systemic (body-wide) Fever – destroys pathogens and enhances immunityFever – destroys pathogens and enhances immunity Chronic inflammation – damages tissuesChronic inflammation – damages tissues Arthritis, asthma, eczema, chronic bronchitisArthritis, asthma, eczema, chronic bronchitis