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Questions and Answers
What primarily stimulates erythropoiesis?
What primarily stimulates erythropoiesis?
- Erythropoietin hormone (correct)
- Liver enzymes
- Testosterone
- Platelet count
Where is the majority of erythropoietin produced in the body?
Where is the majority of erythropoietin produced in the body?
- Liver
- Bone marrow
- Kidneys (correct)
- Spleen
Which of the following conditions can lead to hypoxia?
Which of the following conditions can lead to hypoxia?
- Low red blood cell count (Anemia) (correct)
- High blood pressure
- Increased white blood cell count
- Excessive hydration
Which factor stimulates erythropoietin production apart from hypoxia?
Which factor stimulates erythropoietin production apart from hypoxia?
What role does erythropoietin play in the body?
What role does erythropoietin play in the body?
What is the role of plasmin in the body?
What is the role of plasmin in the body?
Which of the following is essential for the activation of certain clotting factors?
Which of the following is essential for the activation of certain clotting factors?
What condition is caused by a deficiency of platelets?
What condition is caused by a deficiency of platelets?
What effect does warfarin have on the body?
What effect does warfarin have on the body?
What condition is described by the liver's inability to process bilirubin effectively, leading to bilirubin accumulation?
What condition is described by the liver's inability to process bilirubin effectively, leading to bilirubin accumulation?
What is a potential cause of post-hepatic jaundice?
What is a potential cause of post-hepatic jaundice?
Which drug inhibits thrombin by enhancing the activity of antithrombin III?
Which drug inhibits thrombin by enhancing the activity of antithrombin III?
Which type of jaundice is characterized by an unconjugated hyperbilirubinaemia due to excessive breakdown of red blood cells?
Which type of jaundice is characterized by an unconjugated hyperbilirubinaemia due to excessive breakdown of red blood cells?
What is the fate of most bilirubin after conjugation in the liver?
What is the fate of most bilirubin after conjugation in the liver?
Which condition may prevent infants from effectively eliminating bilirubin, leading to jaundice?
Which condition may prevent infants from effectively eliminating bilirubin, leading to jaundice?
Which condition is associated with high erythropoietin levels and polycythemia?
Which condition is associated with high erythropoietin levels and polycythemia?
What is the primary storage form of iron in the liver?
What is the primary storage form of iron in the liver?
What vitamin is essential for the absorption of Vitamin B12?
What vitamin is essential for the absorption of Vitamin B12?
Which vitamin deficiency leads to megaloblastic anemia?
Which vitamin deficiency leads to megaloblastic anemia?
What is the primary role of erythropoietin?
What is the primary role of erythropoietin?
What leads to the development of pernicious anemia?
What leads to the development of pernicious anemia?
Which of these components is NOT part of hemoglobin's iron content?
Which of these components is NOT part of hemoglobin's iron content?
Which factor does NOT affect erythropoiesis?
Which factor does NOT affect erythropoiesis?
What role does albumin play in relation to bilirubin?
What role does albumin play in relation to bilirubin?
What characterizes prehepatic jaundice?
What characterizes prehepatic jaundice?
What is the normal range of bilirubin in the blood?
What is the normal range of bilirubin in the blood?
Which condition is associated with intrahepatic jaundice?
Which condition is associated with intrahepatic jaundice?
What bilirubin level is indicative of jaundice?
What bilirubin level is indicative of jaundice?
What type of cells are included in the category of granular leukocytes?
What type of cells are included in the category of granular leukocytes?
What symptom is characteristic of posthepatic jaundice?
What symptom is characteristic of posthepatic jaundice?
Which cell type is responsible for forming platelets?
Which cell type is responsible for forming platelets?
What is a common treatment for neonatal jaundice with high bilirubin levels?
What is a common treatment for neonatal jaundice with high bilirubin levels?
What is a progenitor cell that can form erythrocytes called?
What is a progenitor cell that can form erythrocytes called?
Which condition might lead to prehepatic jaundice?
Which condition might lead to prehepatic jaundice?
What typically follows a complete obstruction in posthepatic jaundice?
What typically follows a complete obstruction in posthepatic jaundice?
Which of the following is an agranular leukocyte?
Which of the following is an agranular leukocyte?
What happens to the nucleus of a red blood cell during its maturation?
What happens to the nucleus of a red blood cell during its maturation?
What is the normal concentration of unconjugated bilirubin in plasma?
What is the normal concentration of unconjugated bilirubin in plasma?
What is the consequence of excessive breakdown of extravasated blood?
What is the consequence of excessive breakdown of extravasated blood?
Flashcards
Erythropoiesis Stimulation
Erythropoiesis Stimulation
Erythropoiesis, the production of red blood cells (RBCs), is triggered by erythropoietin (EPO), a hormone primarily produced by the kidneys.
Erythropoietin Production Trigger
Erythropoietin Production Trigger
Erythropoietin (EPO) release is stimulated by low oxygen levels in the blood (hypoxia) which can arise from various factors like low RBC count, hemorrhage, high altitude, heart failure, or lung disease.
Kidney's Role in EPO
Kidney's Role in EPO
EPO is mainly produced by fibroblast cells in the kidney's cortex and outer medulla. These cells are highly sensitive to low oxygen levels and release EPO in response.
EPO's Composition and Origin
EPO's Composition and Origin
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Hypoxia's effect on EPO
Hypoxia's effect on EPO
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What is Jaundice?
What is Jaundice?
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Types of Jaundice
Types of Jaundice
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Pre-Hepatic Jaundice
Pre-Hepatic Jaundice
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Intrahepatic Jaundice
Intrahepatic Jaundice
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Post-Hepatic Jaundice
Post-Hepatic Jaundice
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Unconjugated Bilirubin
Unconjugated Bilirubin
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Conjugated Bilirubin
Conjugated Bilirubin
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Neonatal Jaundice
Neonatal Jaundice
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Kernicterus
Kernicterus
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Phototherapy
Phototherapy
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Plasminogen's Role
Plasminogen's Role
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Plasmin's Action
Plasmin's Action
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What Happens to the Clot?
What Happens to the Clot?
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Causes of Excessive Bleeding
Causes of Excessive Bleeding
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How Does Vitamin K Affect Clotting?
How Does Vitamin K Affect Clotting?
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Bilirubin Binding
Bilirubin Binding
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Why Bilirubin Binds Albumin
Why Bilirubin Binds Albumin
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Normal Bilirubin Range
Normal Bilirubin Range
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Jaundice
Jaundice
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Red Blood Cell Characteristics
Red Blood Cell Characteristics
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Scanning Electron Microscopy (SEM)
Scanning Electron Microscopy (SEM)
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Blood Cell Formation
Blood Cell Formation
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Red Blood Cell Production
Red Blood Cell Production
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What stimulates erythropoiesis?
What stimulates erythropoiesis?
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What conditions lead to high erythropoietin levels?
What conditions lead to high erythropoietin levels?
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Hemoglobin's role
Hemoglobin's role
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Types of Hemoglobin
Types of Hemoglobin
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Where is iron stored?
Where is iron stored?
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What is Apotransferrin?
What is Apotransferrin?
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What factors affect erythropoiesis?
What factors affect erythropoiesis?
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What is Intrinsic Factor?
What is Intrinsic Factor?
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Study Notes
Blood Physiology
- Blood is a connective tissue in fluid form, considered the fluid of life. It carries oxygen from lungs to body parts and carbon dioxide from body parts to lungs.
- Blood is red in color. Arterial blood is scarlet red due to oxygenated hemoglobin (HbO2) and venous blood is purple-red due to carbon dioxide.
- Average blood volume in normal adult is 5 liters. In a newborn, its 450 ml, and increases to 5 liters during puberty. In females, it's slightly less, around 4.5 liters, and roughly 8% of body weight in a healthy young adult (70kg).
Blood Composition
- Blood consists of two parts:
- Plasma (55% of blood volume): mainly water (91%), with ions, plasma proteins (albumin, globulin, fibrinogen), nutrients, waste products, gases, and regulatory substances. Plasma has the same ionic composition as interstitial fluid.
- Formed elements (45% of blood volume): Red blood cells (erythrocytes), White blood cells (leukocytes) and Platelets (thrombocytes).
Functions of Blood
- Transport of oxygen, carbon dioxide, nutrients, hormones, and waste products.
- Maintain homeostasis (body temperature, ECF pH).
- Protect against infection (white blood cells, antibodies).
- Blood clotting to prevent blood loss.
Blood Cells Formation
- Erythropoiesis: Formation of red blood cells (RBCs).
- Leucopoiesis: Formation of white blood cells (WBCs).
- Thrombopoiesis: Formation of platelets (thrombocytes).
Hematopoiesis
- Production of blood cells starts in early embryonic life.
- Different locations throughout development: Yolk sac (early weeks), Liver & spleen & lymph nodes (middle trimester), Bone marrow of all bones (last few months)
- After birth, bone marrow of flat bones continues RBC production. The shaft of long bones stops producing RBCs at puberty, though the epiphyses continue.
Sites of Active Bone Marrow
- In adults, red bone marrow is primarily found in the axial skeleton, pelvic and pectoral girdles, and proximal epiphyses of the humerus and femur.
Normal Bone Marrow Conversion
- Stages in humans: Infancy (<1 year) - all red marrow. Childhood (1-10 years) - centralized red marrow. Adolescence (10-20 years) and Adulthood (>25 years) - centralized yellow marrow with some red in certain sites.
Blood Cell Characteristics
- Red Blood Cells (RBCs):
- Biconcave discs, 7.5 µm diameter.
- Flexible membrane.
- No mitochondria, ribosomes, or RNA.
- Anaerobic glycolysis.
- Life span of 120 days.
- Normal count 4.7-5.2 million/mm³.
- Hemoglobin (Hb) concentration 14-16 g/dL.
- Function: transport oxygen and carbon dioxide, buffer.
- White Blood Cells (WBCs): Granulocytes (polymorphonuclear leukocytes): Neutrophils (60%), Eosinophils (2%), Basophils (0.4%). Agranulocytes (mononuclear leukocytes): Lymphocytes (30%), Monocytes (5%).
- Platelets (thrombocytes):
- Small irregular cell fragments (2-3 µm).
- Formed in cytoplasm of megakaryocytes.
- Normal count 150,000-450,000/cu mm of blood.
Erythropoiesis
- Characterized by: Reduction in cell size. Disappearance of the nucleus. Appearance of hemoglobin.
- Production is stimulated by erythropoietin (EPO), a hormone produced by the kidneys in response to hypoxia (low oxygen). Hypoxia can be caused by low RBC count (anemia), hemorrhage, high altitude, prolonged heart failure, or lung disease.
Hemoglobin
- Composed of four globin protein chains (two alpha, two beta).
- Each globin chain has a heme group.
- Heme groups contain iron, which binds oxygen.
- Types of hemoglobin: Hb A (major type in adults), Hb A2, Hb F (fetal hemoglobin).
Iron Metabolism
- Iron is part of hemoglobin and myoglobin.
- Most iron is in hemoglobin (~65%).
- About 1% of iron in various heme compounds.
- Some iron is in plasma (combined with transferrin).
- Some iron is stored in the liver as ferritin.
Extravascular RBC Destruction
- Old or damaged red blood cells are destroyed in the spleen, liver, and bone marrow
- Components are recycled: Heme → bilirubin; Globin → amino acids, Fe2+.
- Bilirubin is processed by the liver and excreted in bile.
Jaundice
- Yellow discoloration of skin/eyes due to bilirubin build up in blood
- Prehepatic Jaundice: Excessive red blood cell breakdown overwhelms liver's ability to conjugate bilirubin.
- Intrahepatic Jaundice: Dysfunction of liver cells, preventing bilirubin conjugation.
- Posthepatic Jaundice: Obstruction of the biliary tree, causing conjugated bilirubin buildup
White Blood Cell Types and Functions
- Neutrophils and macrophages: Phagocytosis (cellular ingestion of foreign matter or pathogens). Neutrophils are the primary responders present in large numbers during infections
- Monocytes: Immature cells in the blood, mature into macrophages in tissues; more powerful phagocytes and can survive for months.
- Eosinophils: Attack and destroy parasites, participate in allergic responses.
- Basophils: Release heparin (prevents blood clotting) and histamine (related to allergic reactions).
- Lymphocytes: Responsible for acquired immunity. B lymphocytes produce antibodies, while T lymphocytes directly destroy infected cells and cancer cells.
Hemostasis and Blood Coagulation
- Hemostasis: Prevention of blood loss when a vessel is ruptured.
- Vascular constriction (spasm): Immediate narrowing of the vessel to reduce blood flow.
- Platelet plug formation: Platelets adhere to collagen exposed by injury; thromboxane and ADP release leads to further platelet aggregation.
- Coagulation (blood clot formation): Cascade of reactions in which fibrinogen is converted into fibrin, forming a mesh that traps blood cells and platelets.
- Clot retraction: Contraction of platelets to tighten the clot, closing the vessel opening further.
- Fibrinolysis: The breakdown of the clot by plasmin, which digests fibrin and other clotting factors.
Anticoagulants
- Substances that inhibit clotting.
- Intravascular factors: Endothelial surface factors (smoothness, glycocalyx layer and thrombomodulin). Inhibit clotting in normal blood vessels. Prostacyclin and Nitric Oxide produced by healthy endothelial cells inhibit platelet aggregation.
- In vitro Anti-coagulants: EDTA, Oxalate, Heparin, Sodium Citrate. They prevent clotting in collected blood samples.
Effects of Anemia and Polycythemia
-
Anemia: Reduced RBC count/hemoglobin; decreased blood viscosity. Increased blood flow and cardiac output because of tissue hypoxia. Reduced resistance to blood flow, leading to higher blood flow throughout the tissues and higher cardiac output.
-
Polycythemia: Increased RBC count, increased blood viscosity; more sluggish blood flow. Reduced venous return to the heart.
Blood Disorders
- Excessive increase in white blood cells in the absence of infection is leukemia. The increase in white blood cells as a result of infection is leukocytosis. Different types of anemia exist, based on the underlying cause such as blood loss, poor diet, or a genetic disorder affecting the red blood cells.
- Various types of blood disorders can occur (polycythemia, anemia, and others). These are characterized by abnormal or reduced numbers/function of blood cells. Causes can range from deficiencies in nutritional aspects of the diet, or genetic diseases that affect blood cell creation and maintenance. Note: This is not an exhaustive list, but highlights the main categories.
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