How is carbon dioxide primarily transported in the blood?
As dissolved gas in plasma
In its solid form
Converted into bicarbonate ions
Attached to white blood cells
The Correct Answer is C
A. As dissolved gas in plasma: Approximately 7% of carbon dioxide is transported physically dissolved in the plasma. While this contributes to the partial pressure of the gas, it represents a minor fraction of the total transport capacity. Most carbon dioxide must undergo chemical transformation for efficient systemic removal.
B. In its solid form: Carbon dioxide exists as a gas at physiological temperatures and pressures and cannot form solids within the human body. Solid carbon dioxide, known as dry ice, occurs only at temperatures far below the biological threshold. Such a state would be incompatible with cellular life.
C. Converted into bicarbonate ions: Roughly 70% of carbon dioxide enters erythrocytes and is converted by carbonic anhydrase into bicarbonate and hydrogen ions. The bicarbonate then diffuses into the plasma in exchange for chloride. This mechanism provides the largest capacity for transporting metabolic CO2 to the lungs.
D. Attached to white blood cells: Carbon dioxide does not utilize leukocytes as primary transport vehicles. While a portion of CO2 binds to the globin chains of hemoglobin to form carbaminohemoglobin, this occurs in red blood cells. White blood cells are specialized for immunological defense rather than gas exchange.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is B
Explanation
False: Arterial blood gases (ABGs) provide definitive data on pH, PCO2, and bicarbonate levels, while serum electrolytes help calculate the anion gap. Together, these tests allow clinicians to differentiate between respiratory and metabolic origins of a disorder. They are the cornerstone of clinical acid-base assessment.
Correct Answer is B
Explanation
A. In the digestive tract: While potassium is ingested through the diet, it is rapidly absorbed into the bloodstream and then sequestered into cells. The lumen of the gut does not serve as a primary storage site. Most potassium is located within the soft tissues.
B. In the intracellular fluid (ICF): Approximately 98% of total body potassium is sequestered within the cells, primarily in skeletal muscle. This high internal concentration is maintained by the active transport of the Na+/K+-ATPase pump. It is essential for maintaining the resting membrane potential.
C. In the extracellular fluid (ECF): Plasma potassium represents only a tiny fraction of the total body store, usually measured between 3.5 and 5.0 mmol/L. Even minor shifts in this ECF concentration can have lethal effects on cardiac rhythm. The ECF is not a reservoir.
D. In the renal filtrate: The kidneys filter potassium, but the vast majority is reabsorbed in the proximal tubule and Loop of Henle. The amount present in the filtrate at any given time is minimal. The renal system manages the narrow margin of potassium excretion.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.