what is the role of a neutrophil?
phagocytosis and killing of microorganisms
what is the role of a eosinophil?
killing of anti-body coated parasites through release of granule contents
what is the role of a basophil?
controlling immune responses to parasites
what is a monocyte?
a circulating precursor cell to macrophage
what is a megakaryocyte?
is source of platelet formation and wound repair
what are erythrocytes for?
oxygen transport
describe the components of blood
- plasma/specialized ECM (55%)
- WBCs/buffy coat (1%)
- RBCs (45%)
what is the major protein in plasma and what does it do?
albumin
- maintains osmotic pressure
what does fibrinogen do?
- contributes to coagulation
- is cleaved to form fibrin (fibers in blood clots)
where does hematopoiesis occur?
in the bone marrow
where does hematopoiesis occur before birth?
- mostly yolk sac
- then in liver and spleen
what cells are ONLY found in the bone marrow?
- hematopoietic stem cells
- Megakaryocytes
name all 5 leukocytes (aka WBCs)
- agranulocytes: lymphocytes & monocytes
- granulocytes: neutrophils, eosinophils, & basophils
where are leukocytes found in a hematocrit tube?
in the buffy coat
what do eosinophils do?
- removes antigen
- have antibody complexes from blood
- have anti-parasitic properties
what do eosinophilic granules contain?
- proteases
- RNase
- phosphatase
- lipase
what do basophilic granules contain and what do they associate with?
- eosinophilic chemotactic factor
- histamine
- heparin
- peroxidase
- Associated with hypersensitivity responses
What do neutrophils do?
- involved with bacterial phagocytosis (ingestion/digestion)
what do neutrophilic granules contain?
- phosphatase = removes phosphate groups
- collagenase = destruction of collagen during wound healing
- lysozyme = antibacterial
- non-enzymatic anti-bacterial basic proteins
what is a band cell?
- slightly immature neutrophil with a U-shaped nucleus
what is maturation of pre-neutrophils inhibited by?
the presence of mature neutrophils
what are the formed elements in blood?
- erythrocytes (RBCs)
- thrombocytes (platelets)
what are some characteristics of erythrocytes?
- biconcave discs (large surface:volume ratio)
- facilitates gas exchange
- filled with hemoglobin-iron containing protein that binds O2 and CO2 reversibly
what are some characteristics of thrombocytes?
- disc shaped structures with intercellular organelles
- fragments of megakaryocytes
- store glycogen to maintain function
