Lead Poisoning and Megaloblastic Anemia (Exam 2) Flashcards
What are the 7 common causes of lead poisoning?
battery production | paint | water pipes | lead weight | gasoline | certain diarrhea meds | dirt eating
What are the 4 effects of lead on the body?
affects protoporphyrin synthesis | direct effect on mitochondria | damages cell membranes | damages CNS cells (unrepairable)
How many children are affected by lead poisoning?
1 in 6 under 6y/o
How does lead inhibit Hb synthesis?
inhibits heme synthesis due to its effect on making protoporphyrin
What are the 4 major causes of megaloblastic anemia?
B12 deficiency | folic acid deficiency | drugs impairng DNA metabolism | idiopathic
What are the 4 causes of B12 deficiency?
inadequate production of intrinsic factor (IF) | terminal ileum disorder | competition for B12 | TCBII (transcobalamin II) deficiency
What are the 4 reasons inadequate production of intrinsic factor causing the megaloblastic anemia can be due to?
gastrectomy | congenital and absence of IF (genetic) | congenital production of dysfunctional IF | pernicious anemia
What is gastrectomy?
removal of stomach = removes parietal cells producing IF
What are the 5 things that result in terminal ileum disorder causing megaloblastic anemia?
Tropical Sprue / Non-tropical Sprue (idiopathic diarrhea) | regional enteritis | intestinal resection | neoplasm | Crohn’s disease
What is competition for B12 causing megaloblastic anemia due to?
bacterial and parasitic infections that also use up B12 stores
What are the 3 causes of folic acid deficiency?
inadequate intake | malabsorption (Tropical and Nontropical Sprue) | increased need for folic acid
In what 4 situations is there an increased need for folic acid?
pregnancy | infancy | malignancy | impaired metabolism (alcohol)
What are the morphological characteristics of megaloblastic anemia in peripheral blood?
macropolycytes | macrocytosis | poikilocytosis
What are the morphological characteristics of megaloblastic anemia in the bone marrow?
erythroid hyperplasia (more RBC) | hyper-segmented megakaryocytes | giant metamyelocytes (large granulocytes with 5-6 lobes)
