Chapter 37: Human Defence System Flashcards
What is a pathogen?
a disease causing organism
What is immunity?
the ability to resist disease
What are the two defence systems called?
general defence system
specific defence system
What does the general defence system do?
acts against all pathogens
What is the first line of defence in the general defence system?
consists of skin, mucous membranes, secretion of skin
What are the 3 possible 2nd line of defence in the general defence system?
white blood cells
defence proteins
inflammation
explain how white blood cells act as a line of defence.
attracted to chemicals of invading micro organisms
surround and ingest pathogens
What is a phagocyte?
a cell that ingests another cell
What is a macrophage?
a large phagocyte
What is phagocytosis?
when a cell surrounds and ingests another cell
Explain how defence proteins work.
activated by infection
prevent multiplication and limit spread of viruses
Explain how inflammation works.
infection causes blood capilleries to diallate
this brings more white blood cells to an area
those cells then fight infection
What does the specific defence system do?
system attacks particular invaders
How does the specific defence system work?
produces antibodies or white blood cells that engulf a particular pathogen
What are monocytes?
white blood cells that become macrophages
they engulf invaders
How do monocytes work?
they engulf invaders
once engulfed part of the invader remains on the surface of the macrophage
What is an antigen?
a foreign molecule on the surface of a monocyte that stimulates the production of antibodies
What are lymphocytes?
white blood cell that produces antibodies as a result of antigens