Defence Mechanisms Flashcards Preview

Biology-5-Cell Recognition and The Immune System > Defence Mechanisms > Flashcards

Flashcards in Defence Mechanisms Deck (11):

How does a body protect itself from pathogens

Skin - forming a barrier to the entry of pathogens and phagocytosis

- cell mediated responses involving t lymphocytes

-humoral responses involving B lymphocytes


Each type of cell, self or non self, had specific molecules on its surface why are proteins most important

They have enormous variety and a highly specific tertiary structure

This variety of 3D structure that distinguishes one cell from another


What do proteins on the surface usually identify


Non self material


Abnormal body cells


Why does a donor tissue for transplant need to be very similar

To minimise effect of tissue rejection, best matches are usually relatives

Immunosuppressant drugs are often administered to reduce the level of the immune response that still occurs


What are the 2 defence mechanisms explain them and give an example

Non specific- response is immediate and the same for all pathogens e.g. physical barrier(skin) and phagocytosis

Specific - response is slower and specific to the pathogen. E.g. cell mediated response ( t lymphocytes) and humoral response ( b lymphocytes)


What happens to lymphocytes that have receptors that exactly fit those of the body’s own cells

They either die or are suppressed


Where are lymphocytes produced

In the bone marrow


After a pathogen gains entry to the body it is often a number of days before the body’s immune system begins to control it. Suggest a possible reason why this is so.

The lymphocytes they will finally control the pathogen need to build up their numbers and this takes time


Suggest why it would be inaccurate that say that the body takes days to respond to the pathogen

The body responds immediately by recognising the pathogen, the delay is in building up numbers of lymphocytes and therefore controlling the pathogen


Pathogen definition

Microorganism that causes disease


Antigen definition

A glycoprotein that triggers an immune response by lymphocytes