Module 2: Normal Leukocytes (Monocytes/macrophages)

Question 1

where do monocytes develop

Answer 1

bone marrow

Question 2

stages of monocyte development (3)

Answer 2

monoblast
promonocyte
monocyte

Question 3

monocytosis

Answer 3

increased monocyte count

Question 4

monoblast characteristics

Answer 4

nucleus round, oval, slightly folded, fine thread-like red-purple chromatin, up to 5 nucleoli
Cytoplasm basophilic with grey coloration, no granules

Question 5

promonocyte characteristics

Answer 5

nucleus folded, convoluted with red-purple chromatin, 0-5 nucleoli
cytoplasm is abundant, blue-grey, often has pseudopods and vacuoles

Question 6

monocyte characteristics

Answer 6

nucleus indented, lacy chromatin

Cytoplasm abundant with very fine granules (frosted appearance) pseudopods and vacuoles common

Question 7

normal rel%

Answer 7

2-9% in adults

higher in newborns and young infants

Question 8

how long do monocytes circulate before moving to tissue

Answer 8

36hrs

Question 9

monocyte

Answer 9

immature cell in blood circulation

Question 10

macrophage

Answer 10

mature cell in tissue
Produce more lysozyme, increase in size
May be fixed or motile

Question 11

Mononuclear phagocyte system (MPS)

Answer 11

another term for reticuloendothelial system (RE cells)

common name: macrophages

Question 12

functions of macrophages (4)

Answer 12

phagocytic response to foreign antigens
immune recognition
iron metabolism
preservation of a youthful and healthy population of blood cells

Question 13

Phagocytic response to foreign antigens

Answer 13

responds chemotactivally to inflammation, phagocytose and kill ingested microorganisms
Neutrophils provide first wave, then macrophages phagocytose dead neutrophils and body tissue

Question 14

activation by cytokines from CD4 T cells (often INF-y)

Answer 14

activated macrophage gets bigger, stickier, aggressive
form folds in membrane to catch more antigens
secretes monokines (IL-1)

Question 15

If any antigens survive lysozyme fusion

Answer 15

the organism is isolated and impounded inside Langhans giant cell granulomas
Formed by fusing together of many macrophages
“walls off” the harmful substance
often occurs in TB

Question 16

How is activation of macrophages suppressed

Answer 16

secretion of prostaglandin E2 (PGE 2) from T4 cells and from macrophages themselves

Question 17

Immune recognition

Answer 17

macrophages act as antigen presenting cells (APC) where they bind, engulf, digest, make antigen immunogenic and then present the processed antigen in association with HLA-D antigens on its membrane surface to T4 (CD4) and B lymphs for recognition

Question 18

IL-1

Answer 18

Interleukin 1
best known monokine
essential in activation of CD4T cells by foreign antigens
stimulates hepatocytes to secrete acute phase proteins
stimulates GM-CSF production by other macrophages
Acts as endogenous pyrogen in inflammatory response

Question 19

Secretory effector cells (functions of mono/macro secretions)

Answer 19

removal of old blood cells
stimulation of self-defense against tumor cells
modulation of immune function
regulation of hematopoiesis
stimulation of inflammatory reactions
removal of infection organisms by phagocytosis

Question 20

Iron metabolism/ preserving healthy blood

Answer 20

removal of dead, defective, aged blood/tissue cells, denatured plasma proteins, lipids, activated coagulation factors and antigen-antibody complexes
SPLEEN AND LIVER SINUSOIDS
phagocytose and digest cells, retaining useful components