U.3 K.A-6 Specific Cellular Defences Against Pathogens Flashcards
Is the third line of defence described as non-specific or specific?
Specific
Which group of cells in the immune system bring about a specific immune response?
- T lymphocytes
- B lymphocytes
All lymphocytes originate in the bone marrow. If they pass to the thymus to complete development, what do they become?
T lymphocytes
If lymphocytes complete all their development in the bone marrow, what type of lymphocyte do they become?
B lymphocytes
What name is given to any foreign molecule that is able to elicit a specific immune response from a lymphocyte?
Antigen
Give some examples of antigens.
- Viruses
- Bacteria
- Cancer cells
- Molecules on the surface of transplanted cells
There are a number of different lymphocytes. What is found on the surface of every lymphocyte that makes each lymphocyte different?
A different antigen receptor
What is each antigen receptor on the surface of each lymphocyte specific to?
One type of antigen
Whenever an antigen attaches to the specific antigen receptors on a lymphocyte, the lymphocyte is activated and responds by dividing repeatedly to form identical lymphocytes. What is this called?
A clonal population
Whenever an antigen enters the body, the B lymphocytes respond by producing what?
Antibodies
What shape is an antibody?
Y-shaped
What is found at the end of each arm of the Y-shaped antibody?
A receptor specific to a particular antigen
When a B lymphocyte becomes activated by the presence of an antigen, it responds by making a clone of B lymphocytes which all make antibody. What other cells are made to produce antibodies of the same type again in the future?
Memory B cells
What name is given to the combination formed when the antibody binds to the foreign antigen?
Antigen-antibody complex
The antigen-antibody complex renders a pathogen inactive. What cells come along and destroy the pathogen(disease causing foreign molecule) by phagocytosis?
Phagocytes
What happens when B lymphocytes respond to a harmless substance such as pollen, dust or feathers?
An allergic reaction occurs
In hayfever, which is an allergic reaction, B lymphocytes produce antibodies which then attach to which cells in the connective tissue?
The mast cells
During an allergic reaction, mast cells over produce which substance which causes, nasal congestion and constricted airways?
Histamine
During anaphylactic shock, so much histamine is released that the blood vessels undergo so much vasodilation. What happens to the blood pressure that can cause death?
The blood pressure drops suddenly
Whenever a phagocyte captures a pathogen, it normally presents some of the pathogen’s antigen on the phagocyte surface. What name is given to the phagocyte in this state?
Antigen-presenting cell
What recognises and binds with these antigens on the surface of an antigen-presenting cell?
A T lymphocyte that has the specific antigen receptor that recognises that particular antigen
When an antigen-presenting cell becomes attached to a T lymphocyte, what two things happen?
- A clonal population of T lymphocytes are made
- Memory T cells are made
The T lymphocytes try and destroy the infected body cells by which process of programmed cell death?
Apoptosis
Apoptosis by T lymphocytes destroy the majority of the infected cell. Which process follows apoptosis to remove any remaining parts?
Phagocytosis
What name is given to cells that the body recognises as part of that person and unique to them?
Self cells
Normally T lymphocytes do not attack ‘self cells’ and only attack ‘non-self cells’. If they attack self cells, what is this called?
Autoimmunity
What autoimmune disease is characterised by the T lymphocytes attacking the insulin-producing cells in the pancreas?
Type 1 diabetes
Name another autoimmune disease where the joints become inflamed.
Rheumatoid arthritis
What name is given to the first time a body produces antibodies to a disease?
Primary response
If a person survives an earlier exposure to a certain pathogen and then becomes exposed again later, what response kicks in?
Secondary response
In which three ways, is the secondary immune response better than the primary response in preventing a disease second time around?
- Antibody production is more rapid
- Produced at a higher level
- Lasts for a longer time
Which cells ensure that the secondary immune response is made possible?
Memory cells
Which lymphocytes are attacked by HIV(Human Immunodeficiency Virus)?
T lymphocytes
What disease follows HIV where the person is susceptible to opportunistic infections such as pneumonia and rare forms of cancer because their immune system is so weak?
AIDS (Acquired Immune Deficiency Syndrome)
