Disease Defences 6.3 Flashcards
What is the essential idea?
The human body has structures and processes that resist the continuous threat of invasion by pathogens
What are the primary defences against a disease?
mucus and skin
How are cuts in the skin sealed?
by blood clotting
From where are clotting factors released?
from platelets
What is the cascade?
the rapid conversion of fibrinogen -> fibrin by thrombin
What is non-specific immunity?
Ingestion of pathogens by phagocytic white blood cells
What is specific immunity?
Production of antibodies by lymphocytes in response to particular pathogens
What do antibiotics block?
processes that occur in prokaryotic cells but not in eukaryotic cells
Why can’t viruses be treated with antibiotics?
because they don’t have a metabolism
What did genes of bacteria evolve to?
resistant genes to antibiotics
What is Chemotaxis?
movement in response to chemicals
Chemotaxis attracts phagocytes as a response to:
- proteins produced by the pathogen
- phospholipids released by damaged cells
What are the steps to attack a pathogen?
- phagocyte attaches the pathogen’s cell surface proteins and then engulfs it
- a phagosome forms (the vesicle that contains the pathogen)
- lysosomes deposit digestive enzymes into the phagosome
- the enzymes break down the pathogen and waste products are expelled through exocytosis