Biology B2 - Lymphocytes ( white blood cells ) - structure and function Flashcards
what is the structure of a white blood cell ?
- have flexible cell membranes , the flexible cell membranes can form extensions to help engulf foreign pathogens.
- They have many lysomes enzymes in the cytoplasm which is useful for breaking up and digesting foreign pathogens.
- some white blood cells have a lobed nucleus
what is the function of white blood cells ?
Protection
The white blood cells will help fight any bacteria or viruses that enter in the body and when fighting with infections they would produce more white blood cells.
what do Phagocytes do ?
They Engulf and eat pathogens in a process called phacotoysis.
what do Lymphocytes do ?
They produce antibodies or anti- toxins to fight against pathogens.
what are B Lymphocytes
B cells are a type of white blood cell that makes infection - fighting proteins called antibodies . Antibodies help to fight pathogens.
why are B cells an important part of our immune system ?
B cells are our body’s defence against harmful pathogens such as viruses , bacteria and parasites that enter your body and make you sick.
what do B lymphocytes do in an Allergic reaction ?
B cell produces antibodies in response to the allergen . This response is designed to dismiss the allergen from the body.
what is the role of T lymphocytes ?
It is to destroy harmful body cells that have been infected by the pathogen and by sending signals that help control your immune system response to threats.
what do T cells also help ?
They also help to protect the body from infections and may help to fight cancer.
Important fact about T cells
some T cells become memory cells . Memory cells remember the virus or infection so that if the pathogen returns your immune system recognizes that specific pathogen and quickly prepares a defence.
What is transplant rejection ?
Transplant rejection is a condition that occurs when the recipients immune system attacks the organ or tissue.
when does transplant rejection happen ?
It happens when the immune system identifies the transplanted organs as foreign and not supposed to be there.
How are T Lymphocytes involved in transplant rejection ?
T Lymphocytes can directly attack the transplanted tissue. When the T lymphocytes recognize the foreign antigens on the transplanted cells , They become activated. Activated T cells can grow rapidly and can kill the foreign cells or recruit other immune cells to help them attack.
How are B lymphocytes involved in transplant rejection ?
B Lymphocytes produce antibodies against the foreign antigens . The antibodies bind to the antigens on the transplanted cells, marking them from destruction. This process can lead to inflammation and damage to the transplanted tissue.
what are 2 important facts about Memory cells ?
- Lymphocytes are produced in response to the specific antigens on a pathogen. After the pathogen is removed some of the lymphocytes contain to remain in the immune system. These are called Memory cells
- If the same pathogen enters the immune system for a second time , the response is much more rapid, This is because the existing memory cells are able to multiply rapidly , producing clones of the specific lymphocyte required to attack and destroy the pathogen before the individual exhibits symptoms.
