3.6 Flashcards
How is the specific immune response brought about?
by lymphocytes that come from stem cells in the bone marrow
What are lymphocytes?
white blood cells involved in the specific immune response. They aid the immune system by identifying specific antigens on pathogens.
What is the specific immune response?
the response that occurs from immune cells recognising particular antigens on the pathogen surface.
the specific immune response involves T and B lymphocytes and antibodies.
What are antigens?
molecules that lie on the surface of pathogens that can be detected by the immune system.
recognised by the body as non-self or foreign
Where are B lymphocytes created from?
the remaining lymphocytes that mature in the bone marrow
What is the role of B lymphocytes?
B lymphocytes produce antibodies in response to detecting specific antigens on the surface of a pathogen, leading to the destruction of the pathogen.
How do antibodies aid in the immune response?
Many antibodies can stick to the pathogen, rendering it inactive.
How does an allergic reaction happen?
B lymphocytes can trigger the immune response to a substance that is not harmful to the body, such as nuts or pollen
Where are T lymphocytes created?
in the thymus
What is the role of T lymphocytes?
T lymphocytes recognise specific antigens on the cell membranes of pathogens and kill these pathogens by initiating apoptosis.
What is apoptosis?
programmed cell death
How do T lymphocytes aid in the immune response?
T lymphocytes kill pathogens by inducing apoptosis. T lymphocytes can also stimulate other immune cells to aid in the immune response by releasing cytokines.
What happens when T lymphocytes don’t recognise the body’s own cells?
When T lymphocytes don’t recognise the body’s own cells, they can respond to self-antigens. This leads to autoimmune disease, where the immune system attacks the body’s own cells.
Describe the importance of cell memory in the immune system
Some B and T lymphocytes survive long-term and act as memory cells. When exposed to an antigen for the second time, these cells are familiar with the required response and rapidly divide and give rise to new and specific clone lymphocytes, made to rackle this specific antigen.
What is HIV?
(human immunodeficiency virus)
a blood-borne virus that attacks the immune system by attacking and destroying T lymphocytes
How does HIV lead to AIDS?
(acquired immunodeficiency syndrome)
the disease caused by HIV, where T lymphocytes have been significantly depleted, making the body very susceptible to infectious diseases.
What is an antigen described as?
non-self or foreign
How does B lymphocytes multiply to form antibodies for immediate use?
A B lymphocyte specific to a foreign antigen responds to the presence of the antigen by multiplying to form a clone of activated B cells.
How does B lymphocytes multiply to form antibodies for future use?
A B lymphocyte specific to a foreign antigen responds to the presence of the antigen by multiplying to form a clone of memory B cells capable of making antibodies.
How is pathogen destroyed?
the formation of an antigen-antibody complex inactivates the pathogen and makes it susceptible to phagocytosis
What is an antibody?
a y-shaped protein molecule.
each of its arms bears a receptor binding site specfic to a particular antigen on a pathogen
How does an allergic reaction happen?
it over-reacts by B lymphocytes responding to harmless substances such as pollen, dust, feather or penicilin
such hypersensitivity in the form of over exaggerated immmune response is alled an allergic reaction
