defence against disease Flashcards
what is a pathogen?
organisms that cause infectious diseases.
when a pathogen enters the body, what attacks them?
phagocyte and lymphocyte
what are the foreign chemical groups in pathogens?
antigens
what attach themselves to only that particular antigen?
an antibody
why might a second infection be milder than a first?
because when the antigen is detected by white blood cells, memory cells are produced as well as antibodies. this means they can live many years in the body, produce antibodies very quickly if the pathogen reinvades the body.
what does a phagocyte do?
engulfs the pathogen.
what does the lymphocyte do?
produce antibodies that destroy the pathogens.
what are different ways and the examples of disease travelling?
- in food, eg. salmonella
- in water, eg. cholera
- bodily fluids, eg. hiv
- by animals, eg. malaria and dysentery
- by contact, eg. athlete’s foot
- in the air, eg. flu
what is an antibiotic?
a drug to kill pathogens
why are antibiotics being prescribed less?
because pathogens have developed a resistance to diseases such as MRSA due to over-prescription.
what is an antiseptic?
a weapon against resistant bacteria that kills pathogens outside the body.
what is immunity?
white blood cells make antibodies against pathogens, and if encountered again they can make then quicker so the pathogen can be killed faster.
what is a vaccine?
a vaccine contains harmless versions of the pathogen which stimulate immunity.
what drug is addictive in smoking?
nicotine
what are the consequences of smoking in blood pressure?
- increases the heart rate directly
- carbon monoxide reduces oxygen-carrying capacity of the blood combining with haemoglobin. this causes the heart rate to increase to compensate.
