Question 1

How is stroma-free hemoglobin solution prepared?

Accepted Answer

Stroma-free hemoglobin solution is prepared by lysing outdated red blood cells and then removing the stroma, leaving behind a solution of hemoglobin.

Question 2

What is the normal life span of an RBC?

Accepted Answer

The normal life span of a red blood cell (RBC) is approximately 120 days. After this time period, the RBC is typically removed from circulation and broken down in the spleen or liver. Choices A, C, and D are incorrect because they suggest considerably shorter life spans for RBCs, which is not the case.

Question 3

Regarding loss of RBC membrane deformability, all of the following are true except:

Accepted Answer

An increase in ATP level would actually improve RBC membrane deformability by increasing the energy available for the membrane to maintain its flexibility. Decrease in ATP levels, increase in calcium levels, and decrease in spectrin phosphorylation level are all associated with loss of RBC membrane deformability.

Question 4

Platelets are anucleated but are composed of organelles. Generally most of these organelles are composed of cytoplastic granules. When stimulated, which one of these granules would be most important in satisfying the metabolic need of the platelet?

Accepted Answer

Dense granules contain high concentrations of ADP and ATP which are crucial for platelet activation and aggregation, and for satisfying the metabolic needs of the platelet during this process. Alpha granules contain various growth factors and clotting factors, but they are not as important for immediate metabolic needs. Lysosomes and coarse granules do not play a significant role in platelet activation and metabolism.

Question 5

What is the normal platelet count range per cubic millimeter?

Accepted Answer

The normal platelet count range per cubic millimeter is 150,000 to 350,000. Option A is too low, option C is too low and option D is too high. Therefore, option B is the best choice.

Question 6

Which of the following statements about perfluorocarbons (PFCs) is not true?

Accepted Answer

PFCs are not currently available for use as a red blood cell substitute in the United States or any other country. Some studies have shown promise for their potential use in medical applications, but further research and testing is needed before they can be approved for use as a blood substitute.

Question 7

Which of the following is not a major factor that influences platelet shape and activation while the platelet is in storage?

Accepted Answer

Volume is not a major factor that influences platelet shape and activation while the platelet is in storage. The major factors that influence platelet shape and activation in storage are pH, agitation, and temperature.

Question 8

In order to maintain ATP levels in stored blood, _____________can be added to CPD to extend the shelf-life of stored RBCs from 21 days to 35 days. This new preservative is designated as CPDA-1.

Accepted Answer

Adenine and glucose are added to CPD to provide energy for ATP synthesis and to improve the shelf-life of stored RBCs. Mannitol and adenine saline are not effective in maintaining ATP levels in stored blood, while Rejuvenix is not a known preservative for RBCs.

Question 9

A rare unit of blood became outdated 48 hours ago but is needed for a patient. Which of the following concepts applies to this situation?

Accepted Answer

Once blood has expired, it cannot be rejuvenated or used. Therefore, option A and D are not viable. Option C is also incorrect because the blood is still physically present and can be rejuvenated with Rejuvesol, washed, and immediately transfused to the patient. So, the best choice is B.

Question 10

If platelets are to be stored for 5 days on a rotator, what is the optimal storage temperature?

Accepted Answer

Platelets are best stored at a temperature range of 20°C to 24°C on a gentle and continuous agitator to maintain their viability and function.

Question 11

What cryoprotective agent is added to red blood cells upon freezing?

Accepted Answer

Glycerol is the most commonly used cryoprotective agent for preserving red blood cells upon freezing. Dextrose and Adsol are used as additives to enhance preservation, but glycerol is the primary agent.

Question 12

Which of the following best describes "integral" membrane proteins?

Accepted Answer

Integral membrane proteins span the entire membrane surface, meaning they are embedded within the lipid bilayer of the membrane rather than residing solely at the cytoplasmic surface. The red blood cell cytoskeleton is formed by other types of proteins, such as spectrin and actin.

Question 13

All of the following are consistent with a "shift to the right" of the hemoglobin-oxygen dissociation curve except:

Accepted Answer

A shift to the right of the hemoglobin-oxygen dissociation curve indicates a decrease in hemoglobin affinity for oxygen, meaning that a higher partial pressure of oxygen is required to achieve the same level of hemoglobin saturation. Increased 2,3-DPG levels and decreased hemoglobin affinity for oxygen (option D) are both consistent with a shift to the right. A saturation of 50% (option B) does not provide information on the position of the curve, as it could be on the left or right side. However, decreased 2,3-DPG levels (option C) would actually cause a shift to the left, increasing hemoglobin affinity for oxygen. Therefore, choice C is not consistent with a shift to the right.

Question 14

The normal position of the oxygen dissociation curve depends on three ligands normally found within the RBC. Which one of the following is not one of these ligands?

Accepted Answer

Na+ ions are not one of the three ligands that affect the position of the oxygen dissociation curve. The three ligands are H+ ions, 2,3-DPG, and CO2.

Question 15

Hemoglobin-based oxygen carriers have been produced from which of the following sources?

Accepted Answer

Hemoglobin-based oxygen carriers have been produced from various sources including bovine (cow) hemoglobin, human hemoglobin, and recombinant hemoglobin, which is genetically engineered.

Question 16

One of the most important controls of hemoglobin's affinity for oxygen is:

Accepted Answer

2,3-Diphosphoglycerate (2,3-DPG) is a small molecule that binds to hemoglobin and reduces its affinity for oxygen. This allows hemoglobin to release more oxygen to tissues that need it. Changes in the concentration of 2,3-DPG in the blood can affect hemoglobin's affinity for oxygen, making it an important control of oxygen delivery to tissues. Glucose, K+, and Ca++ do not significantly affect hemoglobin's affinity for oxygen.

Question 17

Which type of blood storage container is no longer available for use in the United States because it may limit the viability of RBCs?

Accepted Answer

Glass bottles are no longer used for blood storage in the United States because they can limit the viability of red blood cells (RBCs). Modern blood storage uses plastic bags, which are better at preserving the quality and function of stored blood.

Question 18

Generally, the quality control measurements required by various accreditation organizations for platelet concentrates include:

Accepted Answer

Platelet concentrate volume and platelet count are essential quality control measurements required by all accreditation organizations. Additionally, if claims of leukoreduction are made, leukocyte count is also required to be measured. The pH of the unit is also an important parameter that needs monitoring to ensure the platelet concentrate's stability and efficacy. Therefore, all the options are correct, and the best choice is D.

Question 19

What role do platelets play in hemostasis?

Accepted Answer

Platelets play multiple roles in hemostasis. They help maintain vascular integrity, which is important in preventing bleeding in the first place. When there is injury to the blood vessel, platelets are the first to respond and form a temporary "plug" to stop bleeding. Then, they help stabilize this plug by releasing a variety of chemicals that promote healing and clotting. Therefore, all of the above choices are correct.

Question 20

Which of the following events does not occur while RBCs are stored?

Accepted Answer

During storage, RBCs undergo several changes collectively known as storage lesions. One of the well-documented changes is the decrease in 2,3-DPG levels, which leads to an increased affinity of hemoglobin for oxygen, making it less available to tissues. Potassium levels in the storage medium increase due to leakage from the red cells.

Quiz 1: Red Blood Cells and Platelet Preservation: Historical Perspectives and Current Trends