How The Human Body Prevents And Stops Pathogen Invasions Flashcards
How do the lungs defend us from pathogens
Mucus and cilia
Mucus traps organisms.
Cilia sweep away trapped organisms.
How do hair follicles and glands in the skin defend us from pathogens
Produce antiseptic oils
How do clots defend us from pathogens
Form scabs, preventing entry of pathogens.
How do tears defend us from pathogens
They contain antiseptic fluid.
Wash away irritating substances and microbes.
How does the stomach defend us from pathogens
Hydrochloric acid in the stomach kills organisms.
How does the dead outer layer of the skin defend us from pathogens
Forms a barrier to pathogens.
Sweat and oil kill many bacteria.
What are the main stages of what happens to phagocytes during phagocytosis
The phagocyte identifies a pathogen , moves towards it and attaches itself to it.
The receptors of the phagocyte and the proteins of the pathogen bind together.
Cytoplasm surrounds and engulfs pathogen.
Pathogen is killed and digested by the enzymes in the phagocyte.
The pathogen is then broken down into proteins and other molecules.
Indigestible residue is removed.
What are the 2 ways our body can defend itself from infections
Physical barriers and non specific defences to prevent infection.
The action of the lymphocytes (white blood cells)
What are the 7 non specific defences
Tears, skin, large intestines, saliva, respiratory tract, stomach, bladder.
How does the bladder prevent infection
Ursine washes microbes from urethra
How do the large intestines prevent infection
Normal bacterial inhabitants keep invaders in check.
How do phagocytes prevent infection
Phagocytes are the type of white blood cell responsible for ‘mopping up’ infected cells and pathogens that have entered the body. These cells go around ingesting and then digesting microbes. They work like Pac-Man. This process is phagocytosis.
