Study Guide Flashcards Blood

State the 7 physical characteristics of blood.

1. Color (scarlet to dark red) 2. Volume (~5 L) 3. Viscosity (4-5x thicker than water) 4. Plasma solute concentration (0.9%) 5. Temperature (38°C / 100.4°F) 6. pH (7.35-7.45) 7. Fluid connective tissue status

What are the 3 primary functional categories of blood and their specific roles?

Transportation (gases, nutrients, wastes, hormones), Protection (leukocytes against pathogens, platelets/clotting proteins against blood loss), Regulation (body temp, pH via buffers, fluid/osmotic balance)

What are the 3 components seen in a centrifuged blood sample and their relative volume percentages?

Plasma (~55%), Buffy Coat (<1% - Leukocytes & Platelets), Erythrocytes (~44%)

What is hematocrit?

Percentage of volume of all formed elements (clinically refers specifically to the percentage of erythrocytes)

What are the main functions of Red Blood Cells (Erythrocytes)?

Transport oxygen and carbon dioxide; help maintain blood viscosity and oxygen-carrying capacity

What are the dimensions and shape of a mature erythrocyte?

Diameter: ~7.5 µm; Thickness: ~2.6 µm (edge) to 0.75 µm (center); Shape: Biconcave disc

What is the average number of RBCs per cubic millimeter of blood?

4.2 to 6.2 million cells per cubic millimeter (mm³)

Describe the molecular structure of hemoglobin (Hb).

4 globin protein chains (2 alpha, 2 beta), each with a heme group containing an iron ion (Fe2+) at its center

How many hemoglobin molecules are contained in a single red blood cell?

~280 million molecules per erythrocyte

What is the specific function of iron (Fe2+) in hemoglobin?

Binds oxygen weakly to allow rapid attachment in the lungs and rapid detachment in body tissues

Trace the locations of RBC production from early embryonic life into adulthood.

Yolk sac wall (early embryo) -> Liver and spleen/thymus (middle trimester) -> Red bone marrow (latter gestation & childhood) -> Axial skeleton red bone marrow (after age 20)

List the developmental cellular stages of erythropoiesis in red bone marrow.

Hemocytoblast (stem cell) -> Myeloid stem cell -> Proerythroblast -> Erythroblast -> Normoblast -> Reticulocyte -> Erythrocyte

What are reticulocytes, and what does an elevated reticulocyte count signify?

Immature red blood cells containing ribosomes; their presence indicates the rate of active RBC production (increased numbers indicate accelerated erythropoiesis)

Outline the pathway of Erythropoiesis regulation starting with hypoxic kidneys.

Kidneys detect low blood O2 (hypoxia) -> release EPO into blood -> EPO stimulates red bone marrow myeloid cells -> increased RBC production -> higher blood O2 inhibits EPO release (negative feedback)

Which two B vitamins are essential for normal RBC production and DNA synthesis?

Vitamin B12 and Folic Acid (or B-complex vitamins)

What is the average lifespan of a circulating erythrocyte?

Approximately 120 days

Outline the step-by-step breakdown and recycling of destroyed RBCs.

Phagocytized by macrophages in spleen/liver; Globins -> amino acids; Iron -> bound to ferritin/transferrin for reuse; Heme -> biliverdin -> bilirubin -> excreted via bile/urine/feces

Define anemia and list its general clinical symptoms.

Lower percentage of erythrocytes or reduced oxygen-carrying capacity. Symptoms: lethargy, shortness of breath, pallor, palpitations

Briefly describe the 7 types of anemia highlighted in Chapter 18.

Aplastic (marrow destruction), Congenital hemolytic (genetic RBC destruction), Erythroblastic (immature cells), Hemorrhagic (blood loss), Pernicious (lack of intrinsic factor/B12), Sickle-cell (abnormal Hb), Renal failure/Chronic disease (reduced EPO)

What is polycythemia?

An abnormally high percentage of erythrocytes, which increases blood viscosity and forces the heart to work harder

List general characteristics and normal cell counts for Leukocytes (WBCs).

Nucleated with organelles, no hemoglobin, motile/flexible (diapedesis and chemotaxis), mostly reside in tissues. Count: 4,500 - 11,000 per mm³

List the 3 types of Granulocytes, their abundance, and primary functions.

Neutrophils (50-70%, multilobed, acute bacterial infections), Eosinophils (1-4%, bilobed/red granules, parasites/allergies), Basophils (0.5-1%, blue-violet granules, histamine/heparin)

List the 2 types of Agranulocytes, their abundance, and primary functions.

Lymphocytes (20-40%, round nucleus, T/B/NK cell immunity) and Monocytes (2-8%, C-shaped nucleus, transform into macrophages)

What is the developmental lineage of Granulocytes during leukopoiesis?

Hemocytoblast -> Myeloid stem cell -> Progenitor cell -> Myeloblast -> Promyelocyte -> Granulocyte

What are the developmental lineages for Monocytes and Lymphocytes?

Monocytes: Myeloid line -> Monoblast -> Promonocyte -> Monocyte; Lymphocytes: Lymphoid stem cell -> Lymphoblast -> Lymphocyte

State the average lifespans of the 5 leukocyte types.

Neutrophils: hours to days; Eosinophils: days; Basophils: hours to days; Monocytes: days to months (as macrophages); Lymphocytes: months to years

What are the functions, normal count, and lifespan of Thrombocytes (Platelets)?

Form platelet plugs and release procoagulants for hemostasis; Count: 150,000 - 400,000 / mm³; Lifespan: 8 - 10 days

Describe the genesis of platelets (Thrombopoiesis).

Myeloid stem cell -> Megakaryoblast -> Megakaryocyte -> extends proplatelets into blood vessels -> sliced by blood flow into platelets

List the exact components and percentages that make up blood plasma.

Water (92%), Plasma Proteins (7%: Albumin 58%, Globulins 37%, Fibrinogen 4%, Regulatory <1%), Other Solutes (1%: electrolytes, nutrients, gases, wastes)

Name and order the 3 mechanisms of hemostasis.

1. Vascular Spasm (vasoconstriction) 2. Platelet Plug Formation (adhesion & aggregation) 3. Coagulation Phase (fibrin meshwork creation)

How do the intrinsic and extrinsic coagulation pathways differ in activation and factors?

Intrinsic pathway: initiated by internal blood vessel damage (Factors XII, XI, IX, VIII, PF3); Extrinsic pathway: initiated by external tissue damage (Factor III/Tissue Factor, VII, Ca2+)

Outline the Common Pathway of blood coagulation.

Factor X activated -> forms Prothrombin Activator -> converts Prothrombin (Factor II) to Thrombin -> converts soluble Fibrinogen (Factor I) to insoluble Fibrin -> Factor XIII cross-links fibrin polymer

Diagram the ABO blood groups: antigens on RBCs vs antibodies in plasma.

Type A (A antigen, anti-B antibody); Type B (B antigen, anti-A antibody); Type AB (A & B antigens, no antibodies); Type O (no antigens, anti-A & anti-B antibodies)

Explain the Rh blood group system, antigens present, and antibody production conditions.

Rh+ has surface Antigen D (no anti-D antibodies); Rh- has no surface Antigen D (produces anti-D antibodies ONLY after exposure to Rh+ blood)

Define Agranulocytosis, Leucopenia, Leucocytosis, Leukemia, and Mononucleosis.

Agranulocytosis: severe WBC reduction; Leucopenia: low WBC count; Leucocytosis: high WBC count; Leukemia: WBC malignancy; Mononucleosis: viral infection with atypical lymphocytes

Differentiate between Clot Retraction and Fibrinolysis (lysis of blood clots).

Clot Retraction: actinomyosin contracts to squeeze out serum; Fibrinolysis: degradation of fibrin strands by plasmin starting within 2 days

Define Thrombus, Embolus, Embolism, Anticoagulant, and Procoagulant.

Thrombus: stationary clot in unbroken vessel; Embolus: free-floating dislodged mass; Embolism: vessel blockage by an embolus; Anticoagulant: inhibits clotting; Procoagulant: promotes clotting