Nokea
The parents of a child with sickle cell anemia (SCA) are concerned about subsequent children having the disease. What statement most accurately reflects inheritance of SCA?
- A. SCA is not inherited.
- B. All siblings will have SCA.
- C. Each sibling has a 25% chance of having SCA.
- D. There is a 50% chance of siblings having SCA.
Correct Answer: C
Rationale: SCA is an autosomal recessive disorder, so each sibling has a 25% chance of inheriting SCA, 25% chance of being unaffected, and 50% chance of having the trait. SCA is inherited, not all siblings will have it, and 50% applies to the trait, not the disease.
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What statement best describes b-thalassemia major (Cooley anemia)?
- A. It is an acquired hemolytic anemia.
- B. Inadequate numbers of red blood cells (RBCs) are present.
- C. Increased incidence occurs in families of Mediterranean extraction.
- D. It commonly occurs in individuals from West Africa.
Correct Answer: C
Rationale: B-thalassemia major has a higher incidence in Mediterranean populations and is inherited, not acquired. It involves overproduction of unstable RBCs, not inadequate numbers, and is distinct from sickle cell anemia, which is common in West African populations.
In which condition are all the formed elements of the blood simultaneously depressed?
- A. Aplastic anemia
- B. Sickle cell anemia
- C. Thalassemia major
- D. Iron deficiency anemia
Correct Answer: A
Rationale: Aplastic anemia involves bone marrow failure, depressing all blood elements (RBCs, WBCs, platelets). Sickle cell anemia affects hemoglobin, thalassemia major impacts hemoglobin chain production, and iron deficiency reduces RBC size and hemoglobin, not all elements.
The regulation of red blood cell (RBC) production is thought to be controlled by which physiologic factor?
- A. Hemoglobin
- B. Tissue hypoxia
- C. Reticulocyte count
- D. Number of RBCs
Correct Answer: B
Rationale: Tissue hypoxia triggers the kidneys to release erythropoietin, stimulating bone marrow to produce RBCs. Hemoglobin levels indirectly influence this through oxygen delivery, reticulocyte count monitors production, and RBC numbers don?t directly control production.
What information should the nurse include when teaching the mother of a 9-month-old infant about administering liquid iron preparations?
- A. Give with meals.
- B. Stop immediately if nausea and vomiting occur.
- C. Adequate dosage will turn the stools a tarry green color.
- D. Allow preparation to mix with saliva and bathe the teeth before swallowing.
Correct Answer: C
Rationale: Adequate iron dosage turns stools tarry green, indicating sufficient absorption. Iron is best given between meals for acidic absorption, nausea may require dose adjustment, not cessation, and liquid iron should be given through a straw to avoid tooth staining.
What explanation provides the rationale for why iron-deficiency anemia is common during infancy?
- A. Cows milk is a poor source of iron.
- B. Iron cannot be stored during fetal development.
- C. Fetal iron stores are depleted by 1 month of age.
- D. Dietary iron cannot be started until 12 months of age.
Correct Answer: A
Rationale: Cows milk, common in diets of 12-36-month-olds, is low in iron, increasing anemia risk. Fetal iron stores, dependent on maternal stores, last 5-6 months, and iron-fortified foods can be introduced before 12 months via breastfeeding or formula.