blood and lymph WTFSDKJAFVHAJWEHFBJAEFAFV Flashcards
Hematopoietic System
Erythrocytes ideally suited for primary function: transport of oxygen from lungs into peripheral tissues
Hemoglobin: complex molecule consisting of four heme groups & four globins
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Objective measurements of red blood cell parameters: done with instruments estimating mean size of red blood cells & their hemoglobin content
Mean corpuscular volume (MCV)
Mean corpuscular hemoglobin (MCH)
Mean corpuscular hemoglobin concentration (MCHC)
White blood cells participate in body’s defense against infections
Neutrophils: short-lived cells that survive no more than 4 days in peripheral circulation
Monocytes & lymphocytes: long-lived blood cells
Platelets or thrombocytes: essential clotting factors
Malignant transformation of hematopoietic cells may result in solid tumors or leukemia
Anemia
Reduction of hemoglobin in blood to below normal levels
In practice, this means
Anemia may be a consequence of:
Decreased hematopoiesis
Abnormal hematopoiesis
Increased loss or destruction of red blood cells
Decreased Hematopoiesis
Bone marrow failure
- -Aplastic anemia
- -Myelophthisic anemia
Deficiencies of nutrients
- -Deficiency of vitamin B12 & folic acid (megaloblastic anemia)
- -Protein deficiency
Abnormal Hematopoiesis
- Usually a consequence of genetic abnormalities
- Sickle cell anemia
Increased Loss & Destruction of Red Blood Cells
Bleeding
Intrasplenic sequestration
Immune hemolysis
Infections (malaria)
Morphology of Anemias
Normocytic, normochromic anemia
-“Dilutional anemia”
Microcytic, hypochromic anemia
-Iron deficiency
Macrocytic, normochromic anemia
-Deficiency of vitamin B12 and/or folic acid
Anemias characterized by abnormal red blood shapes
-Elliptocytosis, spherocytosis, sickle cell
Aplastic Anemia
Idiopathic, secondary
Bone marrow depleted of hematopoietic cells; consists only of fibroblasts, fat cells, scattered lymphocytes
Anemia, leukopenia, thrombocytopenia
Uncontrollable infections, bleeding tendency, chronic fatigue, sleepiness, weakness
Thrombocytopenia
Deficiency of platelets in the blood.
This causes bleeding into the tissues, bruising, and slow blood clotting after injury.
Iron Deficiency Anemia
Most common form of anemia Hypochromic, microcytic anemia Etiology: Increased loss of iron (e.g., chronic bleeding) Inadequate iron intake or absorption Increased iron requirements
Megaloblastic Anemia
Caused by deficiency of vitamin B12 or folic acid Vitamin B12 deficiency -Pernicious anemia -Lack of gastric intrinsic factor -Atrophic gastritis Folic acid deficiency --Inadequate intake in diet or malabsorption caused by -=intestinal disease Bone marrow -Hypercellular, numerous megaloblasts Peripheral blood -Macrocytic anemia Hypersegmentation of neutrophils
Fatigue, shortness of breath, weakness
Destruction of posterior & lateral columns in spinal cord:
results in loss of sense of vibration, proprioception, & loss of deep tendon reflexes
Hemolytic Anemia
-Increased red blood cell destruction (hemolysis)
-Intracorpuscular defects
Structural abnormalities
Sickle cell anemia, thalassemia, hereditary spherocytosis
-Extracorpuscular defects
Antibodies, infectious agents, mechanical factors
Autoimmune hemolytic anemia, hemolytic disease of newborn, transfusion reactions, malaria, hemolytic anemia caused by cardiac valve prosthesis, disseminated intravascular coagulation
–Anemia (i.e., low erythrocyte count)
-Compensatory erythroid hyperplasia of bone marrow
-Hyperbilirubinemia, jaundice
Sickle Cell Anemia
Substitution of glutamic acid by valine
Synthesis of abnormal beta chain of globin
Most prevalent among African Americans
Multiple infarcts in various organs
Neurologic defects; sharp pain in bones, spleen (autosplenectomy), extremities; retinal infarcts
Hyperbilirubinemia, jaundice (bile stones)
Sickle Cell Anemia:Long-Term Complications
Retarded intellectual development, neurologic deficits
Cardiopulmonary insufficiency
Recurrent infections
Thalassemia
- Genetic defect in synthesis of hemoglobin A (HbA); reduced rate of globin chain synthesis
- No abnormal hemoglobin produced
- Beta-thalassemia: reduced synthesis of beta chain of globin
- Alpha-thalassemia: reduced synthesis of alpha chain of globin
---Thalassemia minor, or thalassemia trait Heterozygotes Mild, nonspecific symptoms ---Thalassemia major Homozygotes Severe, serious disease
Hyperbilirubinemia, jaundice
Chronic anemia that retards growth of children
Impairment of normal intellectual development
Cardiorespiratory insufficiency
*Hemosiderosis(US) or haemosiderosis (Br)
is a form of iron overload disorder resulting in the accumulation of hemosiderin. Types include: Transfusionhemosiderosis. Idiopathic pulmonaryhemosiderosis.