Defence Cells

Question 1

What are the 2 categories of defence cell origin?

Answer 1

Myeloid origin & Lymphoid origin

Question 2

What do myeloid and lymphoid mean?

Answer 2

Myeloid - bone marrow originates

lymphoid - lymphatic system (& thymus)

Question 3

Name the myeloid cells

Answer 3

• Neutrophils
• mast cells
• macrophages (monocyte)
• eosinophils & basophils

Question 4

Name the lymphoid cells

Answer 4

• T cells

- B cells

Question 5

monocyte/macrophage function?

Answer 5

• circulate blood, precursor MONOCYTE
• migrate to tissue, differentiate to MACROPHAGE
• early responders
• PHAGOCYTOSE and PRESENT ANTIGENS

Question 6

Mast cells function?

Answer 6

• granulocytes
• early responders
• migrate from blood, differentiate in tissue
• pathogen protection (particular parasitic worms)
• plays role in allergy

Question 7

Neutrophils function?

Answer 7

• Phagocytic granulocytes (granules - contain degradative enzymes + antimicrobial properties)
• Most abundant/important for innate responses
• ## circulate in blood, move to tissue when needed

Question 8

Basophils & Eosinophils function?

Answer 8

• Granulocyte (granules - contain degradative enzymes + antimicrobial properties)
• contributes to allergy
• major role in defence against parasites, can ingest larger threats
• less abundant than neutrophils

Question 9

What are Dendritic cells and their function?

Answer 9

• Antigen presenting cells
• Move from tissues to lymph nodes passing on info
• Activate T and B cells by presenting antigens

DCs link innate & adaptive immunity together, communicates with both types of immunity cells

Question 10

What are Natural Killer (NK) cells?

Answer 10

• Large cells with granules
• recognise and destroy ABNORMAL cells
• control infections until adaptive immunity comes to place

Question 11

How many groups of T cells?

Answer 11

3 Groups

• T Helper Cells (CD4+)
• Cytotoxic T Cells (CD8+)
• Regulatory T Cells (Tregs)

Question 12

What is a naive T-cell?

Answer 12

A T-cell that has undergone positive/negative selection (central tolerance) at the thymus

Question 13

Function of T-helper cells (CD4+)?

Answer 13

Help and support other immune cells

Question 14

Function of Cytotoxic T cells (CD8+)?

Answer 14

Destroy our own infected cells

Question 15

Function of Regulatory T cells (Tregs)?

Answer 15

suppress/regulate other cells in immune system

Question 16

What are T cells?

Answer 16

• Derived from bone marrow, mature in thymus
• Circulate in blood and the lymph (greater No. @ lymphoid organs)
• Recognise peptides produced by APCs through T cell receptors (TCRs)
• Has diversity in TCR, (TCR repertoire)

Question 17

How many groups of T cells?

Answer 17

3 Groups

• T Helper Cells (CD4+)
• Cytotoxic T Cells (CD8+)
• Regulatory T Cells (Tregs)

Question 18

What is a naive T-cell?

Answer 18

An un-matured T-cell

Question 19

Function of T-helper cells (CD4+)?

Answer 19

Help and support other immune cells

Question 20

Function of Cytotoxic T cells (CD8+)?

Answer 20

Destroy our own infected cells

Question 21

Function of Regulatory T cells (Tregs)?

Answer 21

suppress/regulate other cells in immune system

Question 22

What are T cells?

Answer 22

• Derived from bone marrow, mature in thymus
• Circulate in blood and the lymph (greater No. @ lymphoid organs)
• Recognise peptides produced by APCs through T cell receptors (TCRs)
• Has diversity in TCR, (TCR repertoire)

Question 23

How do memory T-Cells come about?

Answer 23

Naive T-cells differentiate into effector cells once exposed to a presented antigen. Most effector cells are short lived, small % survive and become memory T cells

Question 24

What are B Cells?

Answer 24

• Communicate with T cells
• B cells produce antibodies
• Memory B cells allow for a quicker antibody response to further infection