basics

Question 1

<p>Describe the development of immune cells?</p>

Answer 1

<p>a pluripotent stem cell develops into:</p>

<ul><li>premyeloid progenitor → neutrophils</li><li>Lymphocyte progenitors → T cells (thymus) or B cells (bone marrow)</li><li>Premonocyte progenitor → macrophage</li></ul>

<p>T cell can develop into: Helper cell (Th1 and Th2), Cytotoxic cell or memory cell</p>

<p>B cells produce antibodies and become plasma cell</p>

Question 2

<p>what kind of stem cell do immune cells begin as?</p>

Answer 2

<p>haematopoietic stem cell</p>

<p>(common progenitor cell)</p>

Question 3

<p>list the myeloid lineage</p>

Answer 3

<p>megakaryocyte</p>

<p>erythrocyte</p>

<p>mast cell</p>

<p>myeloblast - basophil, neutrophil, eosinophil, monocyte</p>

Question 4

<p>where do myeloid lineage mature</p>

Answer 4

<p>bone marrow</p>

Question 5

<p>where do lymphoid lineage mature</p>

Answer 5

<p>t cells - thymus</p>

<p>b cells - bone marrow</p>

Question 6

<p>how do innate and adaptive immunity differ</p>

Answer 6

<p>speed of response time</p>

<p>cellular components</p>

<p>function</p>

Question 7

<p>how are cells distinguished as healthy or harmful</p>

Answer 7

<p>through recognition of antigens</p>

Question 8

<p>describe the antigen presentation of t lymphocytes</p>

Answer 8

<p>any nucleated host cell can present intracellular antigens via their MHC I molecule to CD8+ cytotoxic T lymphocytes</p>

<p>professional antigen presenting cells can present extracellular antigens via their MHC II to CD4+ helper T lymphocytes</p>

Question 9

<p>what does a haematopoietic stem cell divide into</p>

Answer 9

<p>myeloid and lymphoid progenitor cells</p>

Question 10

<p>list the lymphoid lineage</p>

Answer 10

<p>natural killer cells</p>

<p>t lymphocytes</p>

<p>b lymphocytes</p>

Question 11

<p>where do t and b cells further differentiate</p>

Answer 11

<p>secondary lymphoid organs</p>

Question 12

<p>what are the divisions of the immune system</p>

Answer 12

<p>innate immunity</p>

<p>adaptive immunity</p>

Question 13

<p>describe the innate response</p>

Answer 13

<p>first line of defence</p>

<p>fast non specific response</p>

Question 14

<p>describe the adaptive response</p>

Answer 14

<p>second line of defence</p>

<p>slow specific response</p>

<ul><li>cell mediated (t lymphocytes)</li><li>humoral (b lymphocytes)</li></ul>

Question 15

<p>what do all nucleated cells display</p>

Answer 15

<p>self markers via a cell membrane protein called the major histocompatibility complex I (MHC I)</p>

Question 16

<p>in humans what is the MHC also referred to as</p>

Answer 16

<p>human leukocyte antigen</p>

Question 17

<p>what are the two types of MHC</p>

Answer 17

<p>MHC I - cell surface of all nucleated cells in body, present self markers or intracellular pathogens</p>

<p></p>

<p>MHC II - on professional antigen presenting cells, present extracellular pathogens</p>

Question 18

<p>examples of professional antigen presenting cells</p>

Answer 18

<p>dendritic cells</p>

<p>macrophages</p>

<p>b lymphocytes</p>

Question 19

<p>define immunological tolerance</p>

Answer 19

<p>immune system learns to become tolerant or unresponsive to a particular antigen</p>

<p>central or peripheral tolerance</p>

Question 20

<p>central tolerance</p>

Answer 20

<p>developed within the primary lymphoid organs (bone marrow and thymus) where immature immune cells are taught to be able to discriminate between host and non host</p>

<p>prevents the release of self reactive t and b lymphocytes into circulation</p>

Question 21

<p>peripheral tolerance</p>

Answer 21

<p>developed within secondary lymphoid organs</p>

<p>mature immune cells released into circulation</p>

<p>if they act inappropriately, they are made useless, destroyed or suppressed by regulatory t lymphocytes</p>

Question 22

how does the innate immune system recognise invading pathogens

Answer 22

pattern recognition receptors (PRRs) located on cell surface membrane

Question 23

examples of PRRs

Answer 23

toll like receptors (TLR)
- most commonly found on monocytes, macrophages and dendritic cells

C-type lectin receptors (CLR)

Question 24

examples of molecular motifs recognised by PRRs

Answer 24

pathogen associated molecular pattern (PAMP)
- lipopolysaccharide (LPS)

damage associated molecular pattern (DAMP)
- dna, histones, ATP