CPA #4 Questions Flashcards
who discovered the existence of protozoa and bacteria?
Antoni van Leeuwenhoek
when were bacteria and protozoa discovered?
protozoa 1674; bacteria 1676
define spontaneous generation
supposed production of living organisms from non-living matter
who coined the idea of spontaneous generation? when?
Aristotle 350 b.c.
who dealt the mortal blow to spontaneous generation?
Louis Pasteur
what was Pasteur’s experiment?
boiled infusions long enough to kill everything; bent neck of flask into “s” shape; allowed air into flask, contained everything needed for life, but did not allow microbes to enter; flask remained sterile 18 months later
how can an exposed Petri dish or exposed test tube alter results of experiment?
dust and microbes in the air can get into tube/ dish and contaminate the experiment
what is the scientific method?
use of observations of controlled experiments to answer questions; observations lead to proposing questions; proposed questions lead to hypothetical answers; combination of question and answer lead to designing an experiment to prove hypothetical answer; based on true results, initial hypothetical question is accepted, rejected, or modified.
what is germ theory of disease? who discovered it? when?
idea that microorganisms are responsible for disease; discovered by Pasteur in 1857
what is the purpose of Koch’s postulates?
they are designed to prove that a specific agent causes a specific disease
list Kochs postulates (4)
- the suspected agent present in every case of the disease.
- that agent must be isolated and grown in pure culture
- the cultured agent must cause the disease when inoculated into healthy susceptible experimental host
- the same specimen should be found in the diseased experimental host
what is the agent in Koch’s postulates?
refers to any fungus, protozoan, bacterium, virus, or other pathogen
explain Semmelweis hypothesis of cadaver particles
hypothesis that medical students carried cadaver particles from autopsy studies into delivery room; particles from cadavers caused puerperal fever (caused by Streptococcus) in women giving birth.
how did Semmelweis hypothesis lead to reduction of nosocomial infections
enforcing hand washing with chlorinated lime water led to the mortality rate dropping in the following year by 17%
how did immunization begin with an unethical experiment
Edward Jenner (1796) inoculated a boy with our from a cowpox lesion in order to protect from contracting smallpox; Jenner had infected not with smallpox pus to prove his theory; experiments on human subjects that intentionally exposed them to deadly pathogens are illegal
Prokaryote
cell walls (most)
reproduce asexually
both heterotrophic and autotrophic
can cause disease in humans
bacteriology
staphylococcus epidermis
bacteria
Prokaryote
cell walls (most)
reproduce asexually
both heterotrophic and autotrophic
can perform photosynthesis
cannot cause disease in humans
archaeology
halo bacterium salinerium
archaea
eukaryote
have cell walls
reproduce asexually and sexually
heterotrophic
cannot perform photosynthesis
can cause disease in humans
mycology
mold, yeast
candida albicans
fungi
eukaryote
have cell walls
reproduce asexually and sexually
autotrophic
can perform photosynthesis
cannot cause disease in humans (secrete toxins)
phycology
seaweed, kelp
algae
eukaryote
no cell wall
reproduce both sexually and asexually
heterotroph
cannot perform photosynthesis
can cause disease in humans
helminthology
tapeworms
helminths
eukaryotes
no cell walls
reproduce sexually and asexually
heterotroph
cannot perform photosynthesis
can cause disease in humans
protozoology
guardia intestinalis
protozoans
acellular
no cell walls
can cause disease in humans
virology
norovirus
virus
protein
can cause disease in humans
mad cow disease
VCJD: varient crutzfield Jacobs disease
prions
eukaryote
exoskeleton
sexual reproduction
heterotroph
can cause disease in humans
entomology
sarcoptes scabiei
arthropods
what are the key components of the female reproductive tract?
2 ovaries, 2 uterine tubes, uterus, mucous membrane lined vagina, external genetalia (clitoris, labia, vaginal opening)
how do microbes enter female reproductive tract?
via mucous membrane lined vagina, typically during sex
how are pathogens usually prevented from growing in the reproductive tract?
normal microbiome, lactobacilli keeps pH at 4.5, inhibiting pathogen growth
what are the key components of the urinary tract?
2 kidneys, 2 ureters, urinary bladder, urethra
what part of urinary system is not usually axenic?
urethra; normally supports growth of some microbiota and is a portal of entry
what parts of urinary system are axenic?
kidneys, ureters, bladder
is the vagina axenic or not?
no
how does the estrogen level effect infection?
higher estrogen levels = higher acidity = inhibits growth of opportunistic pathogens; lactobacilli feed on glycogen and produce lactic acid
how does microbial antagonism affect urogenital infection?
the normal microbiome outcompetes pathogens by decreasing urogenital infection risk
what are the key components of the male reproductive system?
2 testes, scrotum, system of ducts, accessory glands, and the penis
how does circumcision play role in microbial infection?
circumcising the foreskin reduces the area that microbes can invade, which reduces risk of infection; urinary or sexually transmitted microbes can invade the urethra, skin of penis, and/or foreskin.
