part 3;

What type of white blood cells are responsible for general (nonspecific) defenses?

Myeloid

Lymphoid stem cells develop into?

Trained immune responders like lymphocytes

Myeloid cells give rise to?

Neutrophils, eosinophils, basophils, monocytes

What is the main role of white blood cells?

Defend the body against pathogens

White blood cells contain?

Nuclei and organelles

Which white blood cell is the first to arrive at the site of infection?

Neutrophil

Which WBC increases during parasitic infections and allergic reactions?

Eosinophils

Basophils release?

Heparin and histamine

Monocytes become?

Macrophages

What type of WBC produces antibodies?

B cells

What structure do lymphocytes have?

Large nucleus with little cytoplasm

Which WBC has a segmented nucleus and acts as a phagocyte?

Neutrophil

What is the function of eosinophils during allergic reactions?

Release enzymes to reduce inflammation

Diapedesis refers to?

WBC movement into tissues

The movement of WBCs toward chemicals released at infection sites is called?

Chemotaxis

Which WBCs are considered phagocytes?

Neutrophils, eosinophils, and monocytes

What WBC count condition involves too few WBCs?

Leukopenia

A dangerously high WBC count, often seen in leukemia, is called?

Leukocytosis

Which WBCs are affected by vaccines?

Lymphocytes

What type of WBC has granules that stain deep blue and is rare in circulation?

Basophil

Platelets are fragments of?

Megakaryocytes

What is the normal platelet count per microliter?

150,000–500,000

Low platelet count is called?

Thrombocytopenia

What is the average lifespan of a platelet in circulation?

9–12 days

What do platelets initiate?

Clotting

What is the first step in blood clotting (hemostasis)?

Vascular spasm

During the vascular phase, what occurs?

Vessel constriction

What triggers platelet attachment in the platelet phase?

Sticky endothelium and collagen

The function of a platelet plug is to?

Close small breaks in vessel walls

The coagulation phase begins?

After 30 seconds or more

What forms the fibrin mesh during coagulation?

Fibrinogen

What is the purpose of the fibrin mesh?

Seal the vessel by trapping cells

What nutrient is essential for producing clotting factors?

Vitamin K

What ion is required for clotting?

Calcium

The liver produces?

Most clotting proteins

Clot retraction is when?

Platelets pull vessel edges together

What dissolves the clot after healing?

Plasmin

Which substance activates plasminogen?

Thrombin and tPA

What enzyme breaks down fibrin strands?

Plasmin

What is fibrinolysis?

Breakdown of the clot