5.2- PHAGOCYTOSIS Flashcards
What must a pathogen do to infect a body?
must first gain entry
What is the role of the first line of defence?
form physical or chemical barrier to entry
What is the next line of defence if the first line of defence fails?
white blood cells
What are the two types of white blood cells?
phagocytes
lymphocytes
What do phagocytes do?
ingest + destroy pathogen by process called phagocytosis before it can cause harm
What response are lymphocytes involved in?
immune response
What is the second line of defence?
phagocytosis
What type of particles can be engulfed by cells in vesicles formed the cell-surface membrane?
large particles i.e. some types of bacteria
What are the types of white blood cells in the blood that carry out phagocytosis?
phagocytes
What do phagocytes provide?
important defence against pathogens that manage to enter body
What do some of the phagocytes travel in?
the blood
Where can some of the phagocytes move out of and move into?
move out of blood vessels into other tissues
What do the phagocytes move towards? (#1 phagocytosis)
chemical products of pathogens or dead, damaged + abnormal cells act as attractants
What do phagocytes have several of and what do they do? (#2 phagocytosis)
several receptors on their cell-surface membrane that recognise, and attach to chemicals on surface of pathogen
What do phagocytes do after the receptors have attached to the chemicals on the surface of the pathogen? (#3 phagocytosis)
engulf pathogen to form vesicle
What is the vesicle with the pathogen in phagocytosis called?
phagosome
What happens after the phagosome is formed? (#4 phagocytosis)
lysosomes move towards the vesicle and fuse with it
What enzyme is present within lysosomes?
lysozymes
What do the lysozymes do bacteria? (#5 phagocytosis)
destroy ingested bacteria by hydrolysis of their cell walls
What is the process of lysozymes destroying the ingested bacteria by hydrolysis of their cell walls the same as?
digestion of food in intestines, namely hydrolysis of larger, insoluble molecules into smaller, soluble ones
What happens to the soluble products from the breakdown of the pathogen? (#6 phagocytosis)
absorbed into cytoplasm of phagocyte
