Cell Recognition And The Immune System (Includes Phagocytosis) Flashcards
What are the two defence systems
-Nonspecific
-specific
What is nonspecific defence system
Generic defences that are immediate and respond in the same way to each pathogen
What are the two nonspecific defences
-physical and chemical barrier
-phagocytosis
What is a specific defence system
Slower defences that are specific to each pathogen
What are the two specific defences
-cell mediated response
-humoral response
How does cell recognition occur
-specific molecules on the surface of cells enables them to be identified
-the molecules are usually proteins and part of the phospholipid bilayer
-the allow the body to recognise its own cells (self) and foreign cells (non-self)
Where are the surface proteins in cell recognition found
-pathogens
-abnormal cells (cancerous cells)
-cells from another organism of the same species (organ transplant)
-toxins
Name some physical barriers
-skin
-scabs
-tears
-eyelashes
-stomach acid
-nasal hair
-cilia
-goblet cells
What do phagocytes do
-detect and attracted to chemicals or debris
-contain lysosome which contain lysozymes that hydrolyse pathogens
-nonspecific and destroy any nonself antigen cells
What is step one of phagocytosis
Pathogen releases chemicals (chemoattractants) that attract phagocyte
What is step 2 of phagocytosis
Phagocyte have cell service receptors which recognise pathogen antigen is as foreign. Phagocyte changes shape and engulfs the pathogen placing them into vesicles called phagosomes.
What is step 3 of phagocytosis
Fact is, I’m in lysosomes fuse to form a phagolysosome. Lysosome then release lysozymes which digest/hydrolyse the pathogen
What is step 4 of phagocytosis
It’s the pathogen has been hydrolyse to phagocyte presents antigen is from the pathogen on its cell surface membrane and becomes an antigen presenting cell
