B6.3 Monitoring & Maintaining Health 2 Flashcards
How do scabs form?
- Skin cut and starts to bleed (blood leaks out of body)
- Platelets change blood protein fibrinogen to fibrin, forming a network of fibres in the cut
- Red blood cells are trapped in fibres forming a blood clot
- Clot hardens to form a scab, keeping skin clean + time to heal
(In time scab falls off)
How does the skin prevent microorganisms from entering body?
Physical barrier
- dry, dead outer cells are difficult for microorganisms to penetrate
- sweat glands produce oils that help kill microorganisms
How does acid in stomach prevent microorganisms from entering body?
It kills pathogens present in contaminated food or drink
How does the cilia and mucus in airways prevent microorganisms from entering body?
- sticky mucus traps microorganisms
- cilia moves mucus up throat to be swallowed
How do nasal hairs prevent microorganisms from entering body?
Keep out dust and larger microorganisms
How do tears prevent microorganisms from entering body?
Contain lysozymes (enzymes that destroy bacteria)
What is the immune system’s main form of defence?
White blood cells
What are the two types of white blood cells?
Phagocytes- cells that engulf/ingest microorganisms and then make enzymes that digest the microorganism
Lymphocytes- make antitoxins or antibodies
Antibodies
Proteins that bind to antigens on the surface of microorganisms
—> once bound pathogen can be ingested by a phagocyte cell and destroyed
Non-specific defence
Defences that prevent entry of all microorganisms
Are antibodies specific or non-specific defences + why?
Specific
Each antibody binds to only one type of antigen and therefore only one type of microorganism
(Each time a new type of microorganism enters the body, a different lymphocyte makes a new body to fight it)
What happens after a disease has been successfully removed from the body?
- white blood cells are able to make the same antibodies if an infection occurs again
- the body now has immunity to the disease (antibodies destroy pathogen before they can cause illness again)
What are hybridomas?
A fusion of myelomas (cancer cells) and lymphocytes
What are monoclonal antibodies made from?
Made in a laboratory using hybridomas
Produced by a single clone of cells
What do monoclonal antibodies do?
Designed to target a specific toe of cell
—> (like antibodies produced by white blood cells) bind to antigens of target cell = kills cell or prevents it from operating effectively
How are hybridomas made?
Genetically modified mice are injected with the required antigen
—> bodies produce immune response, producing antibodies to the specific antigen
—> antibody-producing lymphocyte cells are collected which cannot survive outside of the body and are therefore fused with myeloma cells from the bone marrow which reproduce indefinitely
—> fused cells = hybridomas
How are monoclonal antibodies produced from hybridomas?
Hybridomas reproduce to form clones
—> each clone produces required antibody which is harvested
—> the proteins = monoclonal antibodies