Red Blood Cells 1 Lecture 1- Exam 1 Correct 100%

What is clinical pathology slide - Answer - Typically antemortem☺ - Making a patient diagnosis via: ◦ Hematology & ◦ Biochemistry ◦ Urinalysis ◦ Blood gas ◦ So much more!!!!!! - Cytology o Examining cells under a microscope - typically from a mass o Tissues and body fluids ◦ Urine, cerebrospinal fluid; peritoneal, pleural, and pericardial effusions - Answer What is clinical pathology? Erythron - Answer All erythroid cells (red blood cells or RBCs) in an animal ◦ Includes precursor cells, and RBCs in blood vessels and sinuses in the spleen, liver, and bone marrow Erythron - Answer hemoglobin - Answer 95% of an erythrocyte is _____ *KNOW THIS!* -Hgb (with Fe2+) transports oxygen from lungs to tissues ◦ In health, hgb is 100% saturated with O2 in arterial blood -*Iron must be in the reduced state (Fe2+) to transport oxygen!* -Hemoglobin bound to Fe3+ (methemoglobin) CANNOT carry oxygen - Answer What is the function of Hemoglobin? Hemoglobin slide - Answer Hemoglobin function slide - Answer 1. Erythrocyte hgb (50-70%) 2. Tissue storage (25-40%) -most of the time in macrophages 3. Remainder in other molecules (myoglobin, cytochromes, enzymes) - Answer Where are the 3 major sites of iron distribution in the body? Body distribution of iron slide - Answer Iron -Hemoglobin synthesis is a series of enzymatic reactions - Answer What is the hemoglobin synthesis dependent on? Hemoglobin synthesis slide - Answer Erythropoiesis - Answer erythrocyte production ◦ Occurs mostly in the bone marrow Extrameduallary hematopoiesis - Answer hematopoiesis outside the bone marrow ◦ *Spleen* ◦ *Liver* ◦ Lymph node, lungs, many others (not as significant) erythrocyte production ◦ Occurs mostly in the *bone marrow* -Erythroid committed stem cells (CFU-E)→rubriblasts (first microscopically recognizable erythroid cell) -*Extrameduallary hematopoiesis*= hematopoiesis outside the bone marrow ◦ Spleen ◦ Liver ◦ Lymph node, lungs, many others (not as significant) - Answer What is Erythropoiesis? hematopoiesis outside the bone marrow ◦ *Spleen!* ◦ *Liver* ◦ Lymph node, lungs, many others (not as significant) - Answer What is Extramedullary hematopoiesis and where does it usually occur? 1. Hormonal factors: ◦ Primarily *erythropoietin* (produced by kidney) 2. Bone marrow factors: ◦ Stem cells ◦ Stroma ◦ Blood supply - Answer What controls Erythropoiesis? (2) Bone marrow microenvironment slide - Answer 1. Horomones: ◦ *Erythropoietin* (produced by kidney) ◦ Corticosteriods ◦ Thyroxine 2. Nutritional factors: A. Nucleic acid metabolism ◦ *Vitamin B12* ◦ Folate B. Cytoplasmic maturation and hemoglobin formation -Amino acids -*Vitamin B6* -*Iron(critical for hgb synthesis)* -Copper - Answer What are the Promoters of Erythropoiesis? (2) 1. Nucleic acid metabolism ◦ *Vitamin B12* ◦ Folate 2. Cytoplasmic maturation and hemoglobin formation -Amino acids -*Vitamin B6* -*Iron(critical for hgb synthesis)* -Copper - Answer What are the nutrition factors that promote erythropoiesis? *EPO is produced by:* - *Kidney* →peritubular interstitial fibroblasts - Liver, CNS tissue, Reproductive organs *EPO production stimulated by tissue hypoxia* *Clinical Importance:* - Chronic renal failure (nonregenerative anemia)- -Human EPO used occasionally in severely anemic patients o development of antibodies against human recombinant protein - Answer What is Erythropoietin produced by? What stimulates its production? Why is it clinically important? Erythropoietin (EPO) - Answer 1. *Estrogen* o Clinically important: - Estrogen producing tumors - Estrogen creams/ pills 2. *TNF and IL-6 (inflammation)* - Anemia of inflammatory disease (nonregenerative anemia - Answer What are some Inhibitors of Erythropoiesis and what are some clinically important scenarios that can cause this? (2) Inhibitors of Erythropoiesis slide - Answer 1. Rubriblast 2. Prorubricyte 3. Rubricyte: basophilic and polychromatophilic ◦ Last mitotic stage 4. Metarubricyte/nRBC ◦ Last stage in which the developing RBC is nucleated 5. Reticulocyte ◦ Anucleated ◦ Larger and more basophilic (more blue) than a mature erythrocyte - still has stainable cytoplasmic RNA 6. Mature erythrocyte - Answer What are the stages of Erythrocycte Development? (6) -Only need to focus on last 3! Metarubricyte/nRBC - Answer ◦ Last stage in which the developing RBC is nucleated Reticulocyte - Answer Stage of Erythrocyte development: ◦ Anucleated ◦ Larger and more basophilic (more blue) than a mature erythrocyte - still has stainable cytoplasmic RNA - Rubriblast→erythrocyte steps: 1. Cells undergo mitoses to produce more erythroid cells that have progressively more hemoglobin 2. As hemoglobin synthesis increases in the developing cell, DNA synthesis decreases and fewer mitotic divisions occur 3. Maturation is characterized by: -Decreasing cell size -Decreasing nuclear size -Increasing chromatin condensation/extrusion of nuclei (polychromatophils and mature RBCs) -Decreasing cytoplasmic basophilia (loss of ribosomes, increased hemoglobin) ◦ Time from erythropoietic progenitor cell→reticulocyte is ~ *5 days* in most species - Answer Describe what occurs with Erythrocyte Development: (Rubriblast -> Erythrocyte) ~ *5 days* - Answer Time from erythropoietic progenitor cell→reticulocyte is _____ in most species 1. Decreasing cell size 2. Decreasing nuclear size 3. Increasing chromatin condensation/extrusion of nuclei (polychromatophils and mature RBCs) 4. Decreasing cytoplasmic basophilia (loss of ribosomes, increased hemoglobin) - Answer Maturation of Erythrocyte development is characterized by: (4 things) Erythrocyte development stages slide - Answer