White blood cells

Question 1

What white blood cells are granulocytes?

Answer 1

• Neutrophils
• Eosinophils
• Basophils
• Mast cells

Question 2

What white blood cells are agranulocytes?

Answer 2

• Lymphocytes
• Mononcytes
• Dendritic cells
• Macrophages

Question 3

What are myeloid cells?

Answer 3

Cells that contribute to the innate immune response

Question 4

What are lymphoid cells?

Answer 4

Cells that contribute to the adaptive immune response (except NK cells)

Question 5

What white blood cells are antigen presenting cells?

Answer 5

• Monocyte
• Dendritic cells
• Macrophages
• Lymphocytes

Question 6

Describe the structure and function of neutrophils

Answer 6

• Polymorphonuclear- irregular, multi-lobed nucleus (normally segmented into 3-5 lobes)
• Granulocyte- prominent cytoplasmic granules
• Phagocyte, so undergoes phagocytosis to kill microorganisms
• Main mediators of innate immunity

Question 7

Describe the structure and function of eosinophils?

Answer 7

• Bilobed nucleus (nucleus has 2 lobes)
• Stain pink with eosin
• Polymorphonuclear
• Larger cells fight parasites
• Key cell in allergy responses

Question 8

Describe the structure and function of basophils

Answer 8

• Nonphagocytes
• Granulocytes
• Polymorphonuclear cells (nucleus bilobed/segmented)
• Stain blue/purple with hematoxylin
• Aid in fighting parasites and response to allergies
• Granules contain histamine, heparin
• Involved in inflammatory response
• Least numerous leukocyte

Question 9

Describe the structure and function of mast cells

Answer 9

• Non phagocytes
• Granulocytes
• Involved in inflammatory response

Question 10

Describe the structure and function of monocytes

Answer 10

• Phagocytes
• Antigen-presenting cells
• Release cytokines to recruit other cells
• Only circulate in blood
• Differentiate into macrophages/ dendritic cells

Question 11

Describe the structure and function of dendritic cells

Answer 11

• Phagocytes
• Antigen- presenting cells
• Release cytokines to recruit other cells
• Circulate in lymph, blood tissue
• Consume large proteins in interstitial fluid
• Break blood borne pathogens into small amino acid chains -> move to lymph node -> present antigens to T cells

Question 12

Describe the structure and function of macrophages

Answer 12

• Phagocytes
• Antigen-presenting cells
• Release cytokines to recruit other cells
• Stay in connective tissue, lymphoid organs
• Not in blood

Question 13

What white blood cells are phagocytic?

Answer 13

• Neutrophils
• Eosinophils
• Monocytes
• Macrophages
• Dendritic cells

Question 14

What white blood cells are myeloid cells?

Answer 14

• Neutrophils
• Eosinophils
• Basophils
• Mast cells
• Monocytes
• Dendritic cells

Question 15

What white blood cells are lymphoid cells?

Answer 15

• NK cells - complete development in bone marrow and these cells contribute to the innate response
• B cells - complete development in bone marrow
• T cells - completes development in thymus

Question 16

Describe the structure and function of NK cells

Answer 16

• Large
• Contain granules
• Primarily target infected, cancer cells
• Kill target cells with cytotoxic granules (punch holes in target cell membranes by binding to phospholipids -> enter cell, trigger apoptosis

Question 17

Describe the function of B cells

Answer 17

• Bind to specific antigens (antigen presentation not needed)
• Capable of phagocytosis, antigen presentation; load antigens on major histocompatibility complex (MHC) II, display to T cells; T-cell activation -> B cells mature into plasma cells; secrete antibodies/ immunoglobulins (B cell receptors in secreted form, mark pathogens for destruction -> ‘humoral immunity’

Question 18

Describe the function of T cells

Answer 18

• Responsible for cell-mediated immunity; bind to specific antigens (antigen presentation needed)
• Naive T cells primed by antigen presenting cells (usually dendritic cells); generally categorised into CD4+ (T helper) , CD8+ ( T cytotoxic) T cells
• T helper cells secrete cytokines to coordinate immune responses, only see antigens on MHC II
• T cytotoxic cells kill target cells, cells with antigens on MHC I