Basic Immunology Flashcards
how can infectious diseases be spread?
- by droplet nuclei
- direct contact
- contaminated food and water
- disease vectors; organism that acts as a carrier of an infectious disease between organisms of a different species
what are non-infectious diseases?
- not caused by pathogens
- cannot be spread
- inherited from malnutrition, lifestyle changes and environment factors
what is a host?
an organism infected by a pathogen
structure of a bacterium?
- prokaryotes; no nucleus and membrane-bound organelles
- single circular DNA plasmids
- peptidoglycan cell wall
- one or more flagella
similarities between eukaryotes and prokaryotes?
- presence of cell surface membrane
- presence of ribosomes
- presence of cytoplasm
- DNA only as genetic material
differences between eukaryotes and prokaryotes?
- eukaryotes are larger than prokaryotes
- cell wall composition
- membrane-bound organelles
- location of genetic material
- site of cellular respiration
- site of photosynthesis
what is pneumococcal disease caused by?
Streptococcus pneumoniae
how is S. pneumoniae transmitted?
- respiratory droplets
- contaminated surfaces and objects
what are some signs and symptoms of S. pneumoniae?
- pain fever and swelling of infected sites
- leads to pneumonia
- chest pain
- cough
- difficulty breathing
- fever
how to treat and prevent S. pneumoniae?
- take antibiotics
- wash hands
- wear a mask
- get a pneumococcal vaccination
- avoid touching eyes, nose and mouth
what are viruses?
obligate intracellular parasites that can reproduce only in a host cell
why are viruses unable to reproduce outside a host cell?
- no essential cellular components
- no essential metabolic enzymes
- cannot carry out metabolism and synthesize proteins
living characteristics of viruses?
- able to acquire and use energy
- reproduce at a fast rate in host cells
- evolve and adapt to environment through time
non-living characteristics of viruses?
- no organelles and cellular components
- cannot carry out metabolism
- cannot synthesize proteins
- cannot grow, move, feed and excrete
characteristics of a virus?
- very small
- host specific
- genetic material (DNA or RNA) enclosed within protein coat capsid
- some viruses contain membranous envelope
how is influenza transmitted?
- droplet infection
- contact with contaminated surfaces
signs and symptoms of influenza?
- incubation period of a day
- high fever
- sore throat
- no excessive mucus
how to treat and prevent influenza?
- take vaccinations
- antiviral drugs that block virions release from infected cells
(pretty much the same actions as with Streptococcus pneumoniae)
properties of lymphocytes and their functions?
- few or no granules
- round nucleus
- little cytoplasm
1. mature into plasma B cells that secrete antibodies
2. mature into memory B cells that differentiate into plasma B cells for subsequent infections
properties of neutrophils and their functions?
- large, pale granules containing hydrolytic enzymes
- multi-lobed nucleus
- short-lived
1. engulfs and destroys foreign bodies through phagocytosis
2. circulates the blood
properties of macrophages and their functions?
- few or no granules
- kidney bean-shaped nucleus
- long lifespan
1. engulfs and destroys foreign bodies through phagocytosis
2. moves freely in organs and tissues
what is a vaccine?
an agent that resembles a pathogen by stimulating lymphocytes to quickly produce antibodies when a pathogen invades
what is the mode of action of vaccines?
- agent that resembles a pathogen enters the body
- antigen binds to the receptor of a lymphocyte complementary to its shape
- lymphocyte differentiates to plasma B and memory B cells
- plasma B cells secrete large amounts of antibodies into the bloodstream
- antibodies bind to antigens on pathogen to kill or mark for phagocytosis
- memory B cells remain in the body to divide rapidly into plasma B cells for subsequent infections to provide immunity
mode of action of antibiotics?
- inhibits the synthesis of bacterial cell wall
- inhibits function of cell surface membrane
- inhibits ribosome function
- inhibits enzyme activity in cytoplasm
- inhibits DNA replication
mode of action for bacteria to become antibiotic-resistant?
- exposed to mutagenic agents
- changes to genetic material
- produce proteins that resist antibiotics
- resistant bacteria survive
- bacteria multiplies and passes down antibiotic-resistant genes to the next generation
