Exam 1 – Dr. Thomason: Leukocytes Flashcards
What are the 2 broad categories of leukocytes?
Polymorphonuclear
Mononuclear
What are the polymorphonuclear leukocytes?
Neutrophils
Eosinophils
Basophils
What are the mononuclear leukocytes?
Monocytes
Lymphocytes
What are leukocytes involved with?
Immunity
What do granulocytes and monocytes do?
Protect against invading organisms and allergies
What do lymphocytes do?
Regulation of the immune system
Where are leukocytes formed?
Bone marrow
Where do most lymphocytes continue to mature and replicate?
Lymphoid tissue (lymph node and spleen)
What are monocytes and neutrophils derived from?
Common progenitor cell (CFU-GM)
What do T and B lymphocytes have a significant role in?
Regulation of immunity
What is the most numerous and most important cell?
Neutrophils
What do neutrophils do?
Phagocytize microorganisms
Eliminate microorganisms via intracellular vesicles
What do neutrophils contain?
Antimicrobial substances in granules
What 2 bone marrow compartments do neutrophils develop in?
Proliferation or mitotic compartment (20%)
Maturation and storage compartment (80%)
What does the release of immature neutrophils lead to?
Left shift
How many days does it take to increase the number of neutrophils?
3-5
How is production regulated?
During microbial invasion and tissue injury, activated leukocytes release growth factors
What specifically are released by leukocytes?
Colony-stimulating factors
What are examples of colony-stimulating factors?
CSF-granulocyte
CSF-granulocyte/macrophage
Increase cellular proliferation, differentiation
Enhance cell function
What do cytokines and interleukins do?
Stimulate marrow release Promote margination and endothelium adhesion Stimulate emigration of neutrophils Induce chemotaxis Enhance phagocytosis
How long do neutrophils survive in the blood? Tissues?
8-10 hours
24-48 hours
Where does neutrophil’s work usually occur?
In tissue, but it can work in circulation
What happens in leukocyte migration?
Neutrophils leave the circulation and enter tissues through a process of diapedesis
What causes neutrophils to move to inflamed tissues?
They are attracted by chemokines and cytokines
What does the primary mechanism of neutrophils involve?
Phagocytosis
What does phagocytosis depend on?
Smooth surfaces
Normal/healthy cells have protective proteins
Antibodies
What does from an oxidative burst?
Oxidizing agents
Superoxide
Hydrogen peroxide
Hypochlorite
What causes tissues to change?
Substances released from tissues and infectious agents
What does vasodilation allow for?
More cells to come to the area to help with inflammation
What do monocytes become in the tissue?
Macrophages
How long do monocytes circulate? Where happens after?
24 hours
Recruited to sites of inflammation
What are the lines of defense?
First line (tissue macrophages) Second line (neutrophil infiltration) Third line (monocyte infiltration)
What is the third line of defense like?
Fewer monocytes
Smaller pools of monocytes
Slower infiltration
Longer to start phagocytosis
What percentage of blood leukocytes are eosinophils?
Less than 2%
What are basophils important in?
Hypersensitivity reactions and allergic reactions
