basic immunology Flashcards
contrast a sign and a symptom
sign: can be observed or measured e.g. coughing/rashes/fever
symptom: can be described or felt by patient e.g. nausea/fatigue
define infectious diseases
- transmissible diseases that can spread from one person to another
- caused by pathogens
define non-infectious diseases
- cannot spread from one person to another
- not caused by pathogens
describe 4 ways infection disease spreads
- droplet nuclei: when someone coughs/sneezes, numerous tiny respiratory droplets containing respiratory tract secretions may hold pathogens, that someone else may breathe in and get infected
- direct contact: sexually transmitted infections are transmitted when a person exchanges body fluids during sexual intercourse with an infected person. diseases like hepatitis B and syphilis can be transmitted from mother to baby through breastfeeding. infectious disease can be spread when blood from infected person comes into contact with mucus membranes/bloodstream of uninfected person
- contaminated food/water: when food/water is not properly stored, they can be contaminated with pathogens
- disease vectors
define disease vector
any organism that acts as a carrier of an infectious disease between organisms of different species
state at least 2 preventive measures for droplet nuclei/contaminated food
- droplet nuclei: wearing of cotton masks/N95 masks/surgical masks
- contaminated food: practsie hygenic food preparation and storage/having good personal hygiene/maintain clean water supply/ensure proper sewage treatment
define host
organism infected by pathogen
describe the structure of a bacterium
- prokaryotes: unicellular organism without a nucleus and membrane-bound organelles
- has single circular DNA as its genetic material
- has peptidoglycan cell wall, small circular DNA molecules called plasmids, and one or more flagella
state the shape of the following bacteria forms:
1. bacillus
2. coccus
3. spirillum
- bacillus: straight, rod-shaped
- coccus: spherical
- spirillum: spiral
state at least 3 of 4 similarities between prokaryotes and eukaryotes
- both are bound by cell surface membrane
- both have cytoplasm
- both have DNA as its ONLY genetic material
- both have ribosomes that synthesise proteins
state at least 4 of 8 differences between prokaryotes and eukaryotes
what is pneumococcal disease caused by
pneumococcus bacterium, Streptococcus pneumoniae
must underline the name of bacterium when writing
describe how pneumococcal disease is transmitted
- by respiratory droplets/droplet nuclei and from contaminated objects/surfaces
- when a person inhales droplet nuclei containing Streptococcus pneumoniae and the droplet nuclei traverse the mouth/nasal passages and reach alveoli in the lungs
state signs and symptoms of pneumococcal disease
- mild infections: pain, fever, swelling of affected body part (sinus, middle ear)
- also lead to life-threatening complications: pneumonia which causes chest pain, cough, breathing difficulties, fever (which can be accompanied by nausea and headache)
pneuomonia is not ONLY caused by this bacterium (also by fungi/viruses)
state at least 3 ways to diagnose pneumococcal disease
any 3:
* blood test
* urine test
* phlegm test
* chest x-ray
* spinal tap
state at least 3 ways to prevent/treat pneumococcal disease
any 3:
* take antibiotics as prescribed
* pneumococcal vaccination
* avoid coming in close contact with people who have the disease
* if sick, cover mouth/nose with tissue when coughing/sneezing, and wear a surgical mask
* wash hands with soap and water / rub with disinfectant when you think you touched a contaminated surface
* avoid touching eyes, nose, mouth
define virus
obligate intracellular parasites that can only reproduce within host cell. they cannot multiply outside a living host cell because they do not have any cellular components or metabolic enzymes essential to carry out metabolism and synthesise proteins
describe two states viruses can exist in
- extracellular: metabolically intert
- intracellular: utilise host cell metabolism to reproduce