Ch. 13-Disorders of Red Blood Cells
Why do so many older people develop anemia
because of chronic disease
Why can skin and mucous membranes are pale in someone who presents with anemia
because of insufficient hemoglobin
Why don't the effects of sickle cell anemia show up until a patient is school aged
because of the different hemoglobin in babies
Why are the red blood cells of older adults are not replaced as promptly as younger people
because of the effects of stress over time
What kind of thalassimias affects only adult hemoglobin
beta thalassimias (alpha affects both fetal and adult)
In what form of thalassemia do Heinz bodies impair DNA synthesis and cause damage to the red cell membrane
beta-thalassemia
What are 3 causes of anemia
blood loss, hemolysis, and impaired RBC production
Red blood cells (erythrocytes) are made in the ________ and destroyed in the _________
bone marrow, spleen
How do you calculate the mean cell volume (MCV) of a red cell
by dividing hematocrit by red cell count
What causes anemia due to raynaud phenomenon
cold-reacting antibodies
Mature red blood cells are also known as _________
erythrocytes
What kind of blood cells is the most common
erythrocytes
What occurs when red cells become less deformable, making it difficult for them to traverse the splenic sinusoids
extravascular hemolysis
True or False: Thalassemias are inherited disorders of platelet synthesis that cause severe bruising and bleeding
false
True or false: iron deficiency anemia only affects infants and toddlers
false
What can provide an index of body iron store for a low hemoglobin count
ferritin
How many molecules of oxygen can be carried by one molecule of hemoglobin
four (each hemoglobin molecule has two alpha and two beta protein chains. Each chain contains one heme group that binds to O2)
Rh disease of the newborn is an example of __________ anemia
hemolytic
What stimulates the secretion of erythropoietin
hypoxia (erythropoiesis is governed for the most part by tissue oxygen needs)
Why would administration of albumin help a burn patient
in burn patients, protein leaks out of the vascular spaces and leads to edema. Administration of albumin will help to increase intravascular volume and blood pressure and decrease edema
What occurs as a result of transfusion reaction
intravascular hemolysis
The rate at which hemoglobin is synthesized depends on availability of which substance
iron (for heme synthesis)
What usually causes microcytic hemochromic anemia
iron defficiency
What is a major complication of beta-thalassemia
iron overload (can be reduced by iron chelation therapy)
How do erythrocytes bring oxygen to the tissues
it binds to its heme groups
What are the benefits of umbilical blood donation
it can provide stem cells for transplantation
What does fluorescent light at 420 nm to 470 nm wavelength do to the bilirubin in physiologic anemia
it converts the bilirubin into a soluble form that is easily excreted in the stool and urine
If red blood cell destruction is excessive, bilirubin production is increased, causing a yellow discoloration of the skin called _________
jaundice
What are caused by impaired DNA synthesis that results in enlarged red cells
megaloblastic anemias (the mean corpuscular volume is over 100 fL)
The function of red blood cells is to transport __________ from the lungs to the tissues
oxygen
What is a form of megaloblastic anemia (elevated MCV) caused by atropic gastritis or gastrectomy, ileal resection, inflammation or neoplasms in the terminal ileum and malabsorption syndromes that leads to failure to absorb vitamin B12
pernicious anemia
What kind of anemia results from a vitamin B12 deficiency
pernicious anemia (from things like gastrectomy)
What causes increased red cell breakdown and the inability of the immature liver to conjugate bilirubin and can develop on the 2nd or 3rd day of life
physiologic jaundice
What is unregulated overproduction of the red cell mass is termed as
polycythemia
What is a neoplastic disease of the pluripotent cells of the bone marrow characterized by an absolute increase in total red blood cell (RBC) mass accompanied by elevated white cell and platelet counts.
polycythemia vera
What is characterized by an absolute increase in total red blood cell mass
polycythemia vera (primary polycythemia)
What results in a loss of plasma volume
relative polycythemia
What results from a physiologic increase in the level of erythropoietin, commonly as a compensatory response to hypoxia (conditions causing hypoxia include living at high altitudes, chronic heart and lung disease, and smoking)
secondary polycythemia
After birth, red blood cells are normally made in what location
the bone marrow
Which organ is responsible for erythropoietin production
the kidneys
What sites are used in all people older than 12 to 18 months of age for a bone marrow biopsy
the posterior or anterior iliac crest, the sternum, and the spinous processes of T10-L4
What organ is particularly vulnerable to abnormal hemoglobin S (associated with sickle cell anemia)
the spleen
What organ is responsible for destruction of red blood cells
the spleen
Why is a biconcave shape best for the erythrocyte
the thinness of the cell membrane enables oxygen to diffuse rapidly between the exterior and innermost regions of the cell
How can polycythemia lead to a blood clot
too much red blood cells cause a thickening of the blood and an increased risk of clots
Sickle cell disease is a chronic disorder that results from changes in the shape, rather than the size, of red blood cells
true
True or false: the rate at which hemoglobin is synthesized depends on the availability of iron for heme synthesis
true
True or false: there are two major types of hemoglobin: adult hemoglobin (HbA) and fetal hemoglobin (HbF)
true
Which foods are rich in folic acid
vegetables (especially greens), fruit, cereal, and meat (however, much of the vitamin is lost in cooking)
When is a blood transfusion recommended
when hemoglobin is below 7 g/dL
What is the typical life span of mature red blood cells
120 days
If an Rh-negative mother is giving birth to an Rh-positive infant, what should the nurse be prepared to administer
Rh immune globulin
Which type of deficiency is caused by pernicious anemia
Vitamin B12
What is a commonly performed screening test that determines the number of red blood cells, white blood cells, and platelets per unit of blood
a CBC (complete blood count)
What is used to diagnose immune hemolytic anemias by detecting the presence of antibody or complement on the surface of the red cell
a Coombs test
What kind of polycythemia results in increased red cell mass
absolute polycythemia
What is the most abundant type of plasma protein
albumin
What is polycythemia
an increased RBC count and hematocrit greater than 50%
__________ anemia describes a primary condition of bone marrow stem cells that results in a reduction of all three hematopoietic cell lines: red blood cells, white blood cells, and platelets
aplastic
What is caused by bone marrow suppression and usually results in a reduction of white blood cells and platelets, as well as red blood cells
aplastic anemia
What describes a disorder that results in a reduction of all three hematopoietic cell lines - red blood cells, white blood cells and platelets
aplastic anemia (in 2/3rds or the cases, the cause is unknown and it is referred to as idiopathic aplastic anemia)
