enst Exam 2 review - lecture 6

define toxicology

study of adverse effect of chemicals on living organism

who is paracelsus ?

• father of toxicology

what did paracelsus believe ?

• microcosm ( small thing- ex:human )must be in harmony with macrocosm ( bigger thing- ex: nature)

define disease

definite pathological process having chastistc set of signs and symptoms which are detrimental to the well being of the individual ( something that is not good for us and has a characteristic set of symptoms in which we can evulate them and identify the origin)

define environment

sum of all surrounding conditions or influences that can affect an organism ( everything that is not inherited)

what are enviromental disease agents

things that brings us disease

what are the three types of environmental disease agents

• chemical agents : exposure to natural or man made toxic substances ( not infectious or contagious)

• physical agents : environmental conditions that permit intense or repeated exposure to situations that negatively impact health

• biological agents : pathogen ( bacteria, virus, microorganism) that can cause disease or infection or pest/ parasites that spread pathogens not always infectious/contagious ( ex: allergens, poisonous animals and plants, man made biological agents)

what Is an infectious disease

when a microbial agent ( pathogens) invades the body and initiates a disease response

define infectiousness

ease of transmission to other host

define infectivity

ability to enter, survive and multiply in a new host

what are non-infectious diseases

disease that result from environmental, physical, social, or chemical factors and cannot be transmitted from host to host

what are acute diseases

diseases that have rapid development, is usually self limiting and of relatively short duration

what is chronic disease

disease that have slow development and tends to last for extended period of time

define endemic

disease that exists in a certain area at a constant rate ( ex: chicken pox)

define epidemic

increase rate of the disease In an area over a short period of time

pandemic

epidemic that spreads over many areas

what are the two types of epidemic outbreaks

1) common source: transmission to many individuals from a common contaminated source or location (ex: tainted food or water, contaminant hot spot)

2) host to host: transmission of microbes from one host to another ( ex: respiratory diseases, sexually transmitted diseases, and vector transmitted diseases)

define reservoir

source of infectious disease agents which can be living organisms or inanimate objects

• provide conditions where orgs may survive and multiply

• provide conditions necessary for transmission

define carrier

individual organisms ( or person) that may or may not exhibit symptoms, but harbors and transmits the disease organism

define zoonosis

animals disease that can be transmitted to humans and vice-versa

define pathogens

infectious biological agent that cause disease or illness to a host

• needs proper environment to survive

• can reproduce, spread and Cause infection/disease

• ex: bacteria, protozoa, viruses, fungi and prions

traits of bacteria

• unicellular

what are the different ways disease can be transmitted

• airborne( coughing, sneezing)

• waterborne ( drinking/ swimming in contaminated water)

• zoonosis

• vector transmitted ( animal “carriers: that transmit pathogen to humans

• fomite ( inanimate objects like handrails, carts, desk, toys)

• soil ( contact to hands, bare feet, consumption)

• nosocomial ( within health care settingb

what are the routes of entry for disease

• inhalation

• ingestion

• absorption ( skin contact with an infected item)

• injection ( a break in the skin allowing agent to enter the body

how does the body fight off disease

the immune system- which is a collection of tissues and mechanisms that protect an organism from disease by identifying and destroying pathogens and other foreign bodies

• does so by detecting antigens ( proteins that trigger an immune response - can be orgs such as bacteria and fungi or biolgical toxins like snake venom and foreign bodies)