U.3 K.A-6 Specific Cellular Defences Against Pathogens

Question 1

Is the third line of defence described as non-specific or specific?

Answer 1

Specific

Question 2

Which group of cells in the immune system bring about a specific immune response?

Answer 2

• T lymphocytes

- B lymphocytes

Question 3

All lymphocytes originate in the bone marrow. If they pass to the thymus to complete development, what do they become?

Answer 3

T lymphocytes

Question 4

If lymphocytes complete all their development in the bone marrow, what type of lymphocyte do they become?

Answer 4

B lymphocytes

Question 5

What name is given to any foreign molecule that is able to elicit a specific immune response from a lymphocyte?

Answer 5

Antigen

Question 6

Give some examples of antigens.

Answer 6

• Viruses
• Bacteria
• Cancer cells
• Molecules on the surface of transplanted cells

Question 7

There are a number of different lymphocytes. What is found on the surface of every lymphocyte that makes each lymphocyte different?

Answer 7

A different antigen receptor

Question 8

What is each antigen receptor on the surface of each lymphocyte specific to?

Answer 8

One type of antigen

Question 9

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?

Answer 9

A clonal population

Question 10

Whenever an antigen enters the body, the B lymphocytes respond by producing what?

Answer 10

Antibodies

Question 11

What shape is an antibody?

Answer 11

Y-shaped

Question 12

What is found at the end of each arm of the Y-shaped antibody?

Answer 12

A receptor specific to a particular antigen

Question 13

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?

Answer 13

Memory B cells

Question 14

What name is given to the combination formed when the antibody binds to the foreign antigen?

Answer 14

Antigen-antibody complex

Question 15

The antigen-antibody complex renders a pathogen inactive. What cells come along and destroy the pathogen(disease causing foreign molecule) by phagocytosis?

Answer 15

Phagocytes

Question 16

What happens when B lymphocytes respond to a harmless substance such as pollen, dust or feathers?

Answer 16

An allergic reaction occurs

Question 17

In hayfever, which is an allergic reaction, B lymphocytes produce antibodies which then attach to which cells in the connective tissue?

Answer 17

The mast cells

Question 18

During an allergic reaction, mast cells over produce which substance which causes, nasal congestion and constricted airways?

Answer 18

Histamine

Question 19

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?

Answer 19

The blood pressure drops suddenly

Question 20

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?

Answer 20

Antigen-presenting cell

Question 21

What recognises and binds with these antigens on the surface of an antigen-presenting cell?

Answer 21

A T lymphocyte that has the specific antigen receptor that recognises that particular antigen

Question 22

When an antigen-presenting cell becomes attached to a T lymphocyte, what two things happen?

Answer 22

• A clonal population of T lymphocytes are made

- Memory T cells are made

Question 23

The T lymphocytes try and destroy the infected body cells by which process of programmed cell death?

Answer 23

Apoptosis

Question 24

Apoptosis by T lymphocytes destroy the majority of the infected cell. Which process follows apoptosis to remove any remaining parts?

Answer 24

Phagocytosis

Question 25

What name is given to cells that the body recognises as part of that person and unique to them?

Answer 25

Self cells

Question 26

Normally T lymphocytes do not attack 'self cells' and only attack 'non-self cells'. If they attack self cells, what is this called?

Answer 26

Autoimmunity

Question 27

What autoimmune disease is characterised by the T lymphocytes attacking the insulin-producing cells in the pancreas?

Answer 27

Type 1 diabetes

Question 28

Name another autoimmune disease where the joints become inflamed.

Answer 28

Rheumatoid arthritis

Question 29

What name is given to the first time a body produces antibodies to a disease?

Answer 29

Primary response

Question 30

If a person survives an earlier exposure to a certain pathogen and then becomes exposed again later, what response kicks in?

Answer 30

Secondary response

Question 31

In which three ways, is the secondary immune response better than the primary response in preventing a disease second time around?

Answer 31

- Antibody production is more rapid - Produced at a higher level - Lasts for a longer time

Question 32

Which cells ensure that the secondary immune response is made possible?

Answer 32

Memory cells

Question 33

Which lymphocytes are attacked by HIV(Human Immunodeficiency Virus)?

Answer 33

T lymphocytes

Question 34

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?

Answer 34

AIDS (Acquired Immune Deficiency Syndrome)