Fighting Disease Flashcards
what features on the human body is a part of the defence system
skin, hairs, mucus, trachea, bronchi, cilla and the stomach
how does the skin prevent diseases
acts as a barrier to pathogens. it also secretes antimicrobial substances which kill pathogens.
how do the hairs and mucus prevent diseases
hair and mucus in your nose trap particles that could contain pathogens.
how do the trachea and bronchi prevent diseases
secrete mucus to trap pathogens
how does the cillis prevent diseases
cilia are hairlike structures, which waft the mucus up to the back of the throat where is can be swallowed.
how does the stomach prevent disease
stomach produces hydrochloric acid, which kills pathogens that make it the far from the mouth
if pathogens make it into your body what helps to destroy them
your immune system
what is the most important part of you immune system
white blood cells
what do white blood cells do
they travel around your body and crawl into every part of you, constantly patrolling for microbes. when they come across an invading they have three lines of attack
what are the three stages that the white blood cell process go through
1) consuming a foreign cell
2) producing antibodies
3) producing antitoxins
what happens in the first stage of the white blood cell process
white blood cells can engulf foreign cells and digest them. this is called PHAGOCYTOSIS
what happens in the second stage of the white blood cell process
1) every invading pathogen has unique molecules (called antigens) on its surface
2) when some types of white blood cell come across a foreign antigen, found and destroyed by other white blood cells.
3) the antibodies produced are specific to that type of antigen - they wont lock on to any others
4) antibodies are then produced rapidly and carried around the body to find all similar bacteria or viruses
5) if the person is infected with the same pathogen again the white blood cells will rapidly produce the antibodies to kill it - the person is naturally immune to that pathogen and wont get ill.
what is the third and final stage of the white blood cell process
these counteract toxins produced by the invading bacteria.
what are the two types of white blood cells
phagocytes and lymphocytes
what do phagocytes produce
phagocytosis, which are particles with foreign antigens, which are engulfed and destroyed
