Midterm 3 Flashcards
Symptoms definition
changes in body function that are felt by a patient as a result of disease
Signs definition
changes in a body that can be measured or observes as a result of disease
Syndrome definition
a specific group of signs and symptoms that accompany a disease
Epidemiology
the study of distribution, frequency and spread of diseases and other related problems within human & populations, aiming at prevention and control of the diseases
Sporadic
infrequent and scattered cases of a disease in a community (occurs only occasionally)
Endemic
disease constantly present in a population
epidemic
an outbreak of a disease in a community. i.e when number of cases exceeds that expected
Pandemic
an epidemic occurring over a wide geographic area, more than one nation over the world.
Disease is a result of what three forces
agent of infection
host
environment
Incidence
number of new cases of a disease in a given area during a given period of time ( new cases divided by individuals at risk)
Prevalence
number of total cases of a disease in a given area during a given period of time, regardless of when it first appeared (total number affected divided by total number of individuals)
Acute disease
symptoms develop rapidly but the disease lasts only a short time
Chronic disease
symptoms develop slowly (long lasting)
Subacute disease
intermediate between acute and chronic
Subclinical disease
no noticeable signs or symptoms (inapparent infections)
Latent disease
causative agent is inactive for a time but then activates and produces symptoms
Local infection
pathogens are limited to a small area of the body
Systemic (generalized) infection
an infection throughout the body; often in the blood
Sepsis
toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins from a focus of infection
Primary Infection
acute infection that causes the initial illness
Secondary infection
opportunistic infection after a primary (predisposing) infection
Incubation Period
interval between initial infection and first signs and symptoms
Prodromal period
short period after incubation; early, mild symptoms
Period of illness
disease is most severe
period of decline
signs and symptoms subside
Period of convalescence
body returns to its prediseased state
Why are Carriers the most dangerous reservoir for infection/
The carriers don’t know they are infected
The carrier moves freely in the population
Chronic carriers may have the infection over a long period of time
Normal Microbiota _______ colonize the host and do not cause disease under normal conditions
permanently
Transient Microbiota may be present for …
days, weeks or months
Distribution and composition of normal microbiota are determined by many factors (4):
nutrients
physical and chemical factors
host defenses
mechanical factors
microbial antagonism is …
a competition between microbes
Normal Microbiota protect the host by: (3)
competing for nutrients
producing substances harmful to invading microbes
affecting pH and available oxygen
Steps of infection
1) Entry of the parasite into the hose
2) Establishment and multiplication of the parasite
Innate (natural) immunity
acts immediately as the first line of defence
non-specific
present from birth
has no memory
5 signs of inflammation include
redness, swelling, hotness, pain and loss of function
Steps of the Inflammatory response
- Vasodilation
- An increase in capillary permeability
- Influx of phagocytes
- Repair
Adaptive (acquired) immunity
third line of defence
are not born with it; but aquired
has memory
self recogntition
diversity
Antigen (Ag)
a substance that causes the body to produce specific antibodies or sensitized T cells
Antibody (Ab)
Proteins made in response to an Ag; can combine with that Ag
Immunoglobulins
serum antibodies
General characteristics of viruses
very small, contain DNA or RNA, no ribosomes, no ATP-generating mechanisms
How can viruses be observed
under an electron microscope
How could you grow a virus in the lab?
Intact animal, embryonated eggs, tissue cultures
