hemo 7

Flashcards covering leukopoiesis, granulocyte maturation, morphologic features, CD markers, myeloid vs lymphoid lineages, CBC calculations, and lymphatic/immunity concepts from the lecture notes.

What is leukopoiesis and the primary purpose of white blood cells?

Leukopoiesis is the production of white blood cells (primarily in the bone marrow). The primary purpose of white blood cells is to protect the body against infections, foreign invaders, and abnormal cells.

What is the maturation sequence of the granulocytic series?

Myeloblast → Promyelocyte → Myelocyte → Metamyelocyte → Band cell → Mature granulocyte (neutrophil, eosinophil, basophil).

Name four morphologic features that help differentiate cells of the granulocytic series.

Nuclear shape: round in myeloblasts; Cytoplasmic granules: non-specific; Cell size decreases with maturation; Nucleoli: present in early stages.

What are the major CD markers for T cells?

CD3 (all), CD4 (helper), CD8 (cytotoxic).

What are the major CD markers listed for B cells?

CD19, CD20, CD2.

What are the major CD markers listed for NK cells?

CD3-negative.

What are the major CD markers listed for Monocytes?

Marker not specified in notes.

What are the major CD markers for Neutrophils?

CD15, CD11b.

What are the major CD markers for Eosinophils?

CD125 (IL-5 receptor).

What are the major CD markers for Basophils?

CD123, CD203.

Describe the function of the myeloid stem cell relative to the lymphoid stem cell.

Myeloid stem cells give rise to granulocytes, monocytes, erythrocytes, and megakaryocytes; lymphoid stem cells give rise to lymphocytes (T cells, B cells, and NK cells). Thus myeloid cells contribute to innate immunity and other blood components, while lymphoid cells are central to adaptive immunity.

Using the Rule of 3, what is the approximate Hematocrit (HCT) when Hb = 13.4 g/dL?

HCT ≈ Hb × 3 = 40.2%.

If RBC = 5.6 × 10^12/L, what is Hb approximately?

Hb ≈ RBC × 3 = 16.8 g/dL.

How do you calculate MCV given HCT and RBC?

MCV = (HCT/RBC)10 (with consistent units).

Calculate MCV when HCT = 40.4% and RBC = 4.79 × 10^12/L.

MCV ≈ (40.4 × 10) / 4.79 ≈ 84.3 fL.

Calculate MCH given Hgb = 12.9 g/dL and RBC = 4.79 × 10^12/L.

MCH ≈ (Hgb × 10) / RBC = (12.9 × 10) / 4.79 ≈ 26.9 pg.

What is the normal MCV range?

80–100 fL.

True or False: The normal MCHC range is 42–46%.

False; normal MCHC is about 32–36 g/dL.

How do you calculate the absolute value of lymphocytes?

Absolute lymphocyte count = Total WBC × % lymphocytes.

What is the relative value of segmented neutrophils given counts: Segmented 52, Lymphocytes 30, Eosinophils 5, Basophils 13 (out of 100 cells)?

52%.

What is the difference between absolute and relative WBC values?

Absolute value is the actual number of a specific WBC per microliter; Relative value is the percentage of a specific WBC relative to total WBC.

Describe the lymphatic system and its relationship to lymphocyte production.

The lymphatic system is a network of vessels, nodes, and organs that supports immune function: filters lymph, transports lymphocytes, and provides sites for lymphocyte activation and proliferation (lymph nodes). Primary lymphoid organs are bone marrow and thymus; secondary lymphoid organs are lymph nodes, spleen, and tonsils.

What is the role of T cells?

Part of adaptive immunity; CD4+ T cells help activate B cells and macrophages; CD8+ T cells kill virus-infected and cancerous cells.

What is the role of B cells?

Produce antibodies; when activated, differentiate into plasma cells that secrete antibodies specific to pathogens.

What is the role of NK cells?

Part of innate immunity; destroy virus-infected and tumor cells without prior sensitization; recognize stressed cells in the absence of antibodies or MHC.