Lecture 4 1/23/24

Question 1

Why are neutrophils and monocytes similar?

Answer 1

they derive from the same bipotential precursor cell

Question 2

Which cells make up the mitotic pool in the bone marrow?

Answer 2

-myeloblasts
-promyelocytes
-myelocytes

Question 3

What happens to the majority of myelocytes produced in healthy animals?

Answer 3

they undergo programmed cell death and do not mature

Question 4

Which cells make up the maturation pool?

Answer 4

-metamyelocytes
-band neutrophils
-segmenter neutrophils

Question 5

What are the differences between the circulating neutrophil pool and the marginated neutrophil pool?

Answer 5

-marginated neutrophil pool remains adhered to the blood vessel walls
-only circulating neutrophil pool neutrophils are collected in a blood sample

Question 6

Why are there more marginated neutrophils in capillaries and post-capillary venules?

Answer 6

these vessels have lower blood flow rate, allowing more neutrophils to adhere to the vessel walls

Question 7

How do the number of neutrophils in the MNP compare to the number of neutrophils in the CNP in different species?

Answer 7

-MNP = CNP in canine, equine, bovine
-MNP 3x greater than CNP in feline

Question 8

What is physiologic/shift neutrophila?

Answer 8

the release of MNP neutrophils into circulation during stress, which can appear as inflammation on bloodwork

Question 9

What is stress neutrophila?

Answer 9

decreased attachment of neutrophils to vessel walls and release of neutrophils from storage pool in response to increased cortisol levels

Question 10

How long do neutrophil precursors remain in the proliferation pool?

Answer 10

2-3 days

Question 11

How long do neutrophil precursors remain in the maturation pool?

Answer 11

2-3 days

Question 12

How does WBC count compare to RBC count?

Answer 12

WBCs is a much lower proportion of blood than RBCs

Question 13

Which WBCs are most common in the blood, in order?

Answer 13

-neutrophils
-lymphocytes
-monocytes

Question 14

What are the effects of systemic recruitment on neutrophils?

Answer 14

increased:
-proliferation
-differentiation
-function
-bone marrow release
-margination/emigration

Question 15

What are the methods for increasing neutrophil production?

Answer 15

-increased stem cell recruitment
-increased effective granulopoiesis (less programmed cell death, more cells mature)
-shortened maturation time

Question 16

What are the characteristics of neutrophil release from the bone marrow?

Answer 16

-orderly and age-related
-neutrophils in the stored pool are released before new neutrophils are produced

Question 17

What are the characteristics of left shift?

Answer 17

-seen during increased demand for neutrophils
-bands neutrophils and other, younger forms of neutrophils are prematurely released

Question 18

What are the steps of leukocyte adhesion?

Answer 18

-margination
-rolling
-integrin activation by chemokines
-stable adhesion
-migration through epithelium

Question 19

Which cells produce the chemokines that activate integrin?

Answer 19

macrophages

Question 20

What are the functions of neutrophils?

Answer 20

-phagocytosis/killing bacteria
-kill/inactivate other pathogens
-inflammatory mediators
-tissue damage

Question 21

Which “weapons” are used by neutrophils to kill bacteria/pathogens?

Answer 21

-myeloperoxidase
-lysozyme
-bactericidal/permeability-increasing protein
-collagenases
-gelatinases
-lactoferrin

Question 22

Which neutrophil “weapons” fall into the azurophil granules category?

Answer 22

-myeloperoxidase
-lysozyme
-bactericidal/permeability-increasing protein

Question 23

What are the characteristics of eosinophil production/kinetics?

Answer 23

-mature similarly to neutrophils
-have both storage and marginated pools
-30 min. circulating half-life
-emigrate into sub-epithelial sites

Question 24

What are the functions of eosinophils?

Answer 24

-parasite elimination
-hypersensitivity/allergic reaction suppression
-infiltration of certain tumors

Question 25

What are the characteristics of basophil production/kinetics?

Answer 25

-mature similarly to neutrophils and eosinophils
-production stimulated by IL-3
-storage pool exists
-6 hr circulating half-life
-activated by IL-3 or IgE binding

Question 26

What are the functions of basophils?

Answer 26

-elimination of parasites
-promote allergic/hypersensitivity reactions

Question 27

Which leukocyte is the largest?

Answer 27

monocytes

Question 28

What are the characteristics of monocyte production/kinetics?

Answer 28

-derived from bipotential stem cell
-no maturation or storage pools
-marginated and circulating pools exist
-survive in tissue for weeks-years

Question 29

What are the functions of monocytes?

Answer 29

-phagocytize/kill organisms
-phagocytize/digest foreign material
-antigen presentation
-synthesis of CSFs and cytokines
-elimination of viral-infected and tumor cells

Question 30

Which leukocyte is the smallest?

Answer 30

lymphocytes

Question 31

What are the characteristics of lymphocyte production/kinetics?

Answer 31

-originate from common lymphoid precursor in bone marrow
-differentiate and mature in primary lymphoid tissues
-colonize in secondary lymphoid tissues
-long lived
-marginated pool exist
-majority are T cells

Question 32

What is unique to WBCs?

Answer 32

ability to recirculate

Question 33

What are the functions of lymphocytes?

Answer 33

-antibody production (B and plasma cells)
-immuno-regulation (B and T cells)
-kill virus-infected and tumor cells (T and NK cells)