Cells- Defence Mechanisms Flashcards
What is meant by a defence mechanism?
The human body has a range of defences to protect itself from pathogens. Some are general and immediate defences like the skin forming a barrier to the entry of pathogens and phagocytosis. Others are more specific, less rapid but longer-lasting.
What two defences mechanisms involve a lymphocyte?
Cell-mediated responses involving t lymphcytes.
Hu,oral responses involving B lymphocytes.
What is meant by recognition of own cells?
To defend the body from invasion of foreign material, lymphocytes must be able to distinguish the body’s own cells and molecules (self) from those that are foreign (non-self). If they could not do this, the lymphocytes would destroy the organisms own tissues.
How can a self, non-self cell be identified?
It has molecules on its surface that identify it. While these molecules can be of a variety of types, it is the proteins that are most important. This is because proteins have enormous variety and a highly specific tertiary structure. It is this varied of specific 3-D structure that distinguishes one cell from another.
